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HomeMy WebLinkAbout20230222Attachment C.pdfAvista’s Application to Revise its Electric and Natural Gas Book Depreciation Rates Attachment C: Gannett Fleming, Inc. Depreciation Study 2021 DEPRECIATION STUDY CALCULATED ANNUAL DEPRECIATION ACCRUALS RELATED TO ELECTRIC, GAS AND COMMON PLANT AS OF DECEMBER 31, 2021 Prepared by: Attachment C J. Spanos, AvistaPage 1 of 800 AVISTA CORPORATION Spokane, Washington 2021 DEPRECIATION STUDY CALCULATED ANNUAL DEPRECIATION ACCRUALS RELATED TO ELECTRIC, GAS AND COMMON PLANT AS OF DECEMBER 31, 2021 GANNETT FLEMING VALUATION AND RATE CONSULTANTS, LLC Camp Hill, Pennsylvania Attachment C J. Spanos, Avista Page 2 of 800 January 3, 2023 Avista Corporation 1411 Mission Avenue Spokane, WA 99220-3727 Attention: Ryan Krasselt Vice President, Controller and Principal Accounting Officer Ladies and Gentlemen: Pursuant to your request, we have conducted a depreciation study related to the electric, gas and common plant of Avista Corporation (“Avista”) as of December 31, 2021. The attached report presents a description of the methods used in the estimation of depreciation, the summary of annual depreciation accrual rates, the statistical support for the life and net salvage estimates and the detailed tabulations of annual depreciation. Respectfully submitted, GANNETT FLEMING VALUATION AND RATE CONSULTANTS, LLC JOHN J. SPANOS President JJS:jmr 069194.000 Attachment C J. Spanos, Avista Page 3 of 800 TABLE OF CONTENTS Executive Summary .............................................................................................. iii PART I. INTRODUCTION ....................................................................................... I-1Scope ..................................................................................................................... I-2Plan of Report ......................................................................................................... I-2 Basis of the Study ................................................................................................... I-3Depreciation ................................................................................................. I-3Service Life and Net Salvage Estimates ....................................................... I-4 PART II. ESTIMATION OF SURVIVOR CURVES .................................................. II-1Survivor Curves ....................................................................................................... II-2 Iowa Type Curves ......................................................................................... II-3Retirement Rate Method of Analysis ............................................................ II-9Schedules of Annual Transactions in Plant Records .................................... II-10 Schedule of Plant Exposed to Retirement .................................................... II-13Original Life Table ....................................................................................... II-15Smoothing the Original Survivor Curve ........................................................ II-17 PART III. SERVICE LIFE CONSIDERATIONS ...................................................... III-1Field Trips ............................................................................................................... III-2 Service Life Analysis ............................................................................................... III-4Life Span Estimates ...................................................................................... III-9 PART IV. NET SALVAGE CONSIDERATIONS .................................................... IV-1Net Salvage Analysis .............................................................................................. IV-2Net Salvage Considerations ......................................................................... IV-2 PART V. CALCULATION OF ANNUAL AND ACCRUED DEPRECIATION .......... V-1Group Depreciation Procedures .............................................................................. V-2 Single Unit of Property .................................................................................. V-2Remaining Life Annual Accruals ................................................................... V-3Average Service Life Procedure ................................................................... V-3 Calculation of Annual and Accrued Amortization .................................................... V-4 PART VI. RESULTS OF STUDY ........................................................................... VI-1 Qualification of Results ............................................................................................ VI-2Description of Detailed Tabulations ......................................................................... VI-2 _____________________________________________________________________________________________ Avista Corporation December 31, 2021L Attachment C J. Spanos, Avista Page 4 of 800 TABLE OF CONTENTS, cont. Table 1. Summary of Estimated Survivor Curve, Net Salvage Percent, Original Cost, Book Depreciation Reserve and Calculated Annual Depreciation Accruals Related to Electric, Gas and Common Plant as of December 31, 2021 ................................................................ VI-4 PART VII. SERVICE LIFE STATISTICS ................................................................. VII-1 Electric Plant................................................................................................. VII-2 Gas Plant .................................................................................................... VII-186 Common Plant ............................................................................................ VII-263 Electric, Gas and Common Plant ................................................................ VII-268 PART VIII. NET SALVAGE STATISTICS .............................................................. VIII-1 Electric Plant............................................................................................... VIII-7 Gas Plant ................................................................................................... VIII-93 Common Plant ............................................................................................ VIII-110 Electric, Gas and Common Plant ................................................................ VIII-112 PART IX. DETAILED DEPRECIATION CALCULATIONS ..................................... IX-1 Electric Plant................................................................................................. IX-2 Gas Plant ...................................................................................................... IX-209 Common Plant .............................................................................................. IX-297 _____________________________________________________________________________________________ Avista Corporation December 31, 2021LL Attachment C J. Spanos, Avista Page 5 of 800 AVISTA CORPORATION DEPRECIATION STUDY EXECUTIVE SUMMARY Pursuant to Avista Corporation’s (“Avista” or “Company”) request, Gannett Fleming Valuation and Rate Consultants, LLC (“Gannett Fleming”) conducted a depreciation study related to Avista’s electric, gas and common plant as of December 31, 2021. The purpose of this study was to determine the annual depreciation accrual rates and amounts for book and ratemaking purposes. The depreciation rates determined as a result of this study are based on the straight line method using the average service life (“ASL”) procedure and were applied on a remaining life basis. The calculations were based on attained ages and estimated average service life and net salvage for each depreciable group of assets. Avista’s accounting policy has not changed since the last depreciation study was prepared as of December 31, 2016. There have been significant changes to plant in service and the average service life and net salvage parameters have been updated. The proposed depreciation rates produce an overall increase for electric, gas and common plant as of December 31, 2021. Specifically, electric plant increases and gas and common plant decrease slightly. Gannett Fleming recommends the calculated annual depreciation accrual rates set forth herein apply specifically to electric, gas and common plant in service as of December 31, 2021 as summarized in Table 1 of the study. Supporting analysis and calculations are provided within the study. _____________________________________________________________________________________________ Avista Corporation December 31, 2021LLL Attachment C J. Spanos, Avista Page 6 of 800 The study results set forth an annual depreciation expense of $189.8 million when applied to depreciable plant balances as of December 31, 2021. The results are summarized at the functional level as follows: SUMMARY OF ORIGINAL COST, PROPOSED ACCRUAL RATES AND AMOUNTS ORIGINAL COST AS OF ACCRUAL ACCRUAL FUNCTION DECEMBER 31, 2021 RATE AMOUNT ELECTRIC PLANT Steam Production Plant 445,087,172.12 4.31 19,195,620 Hydro Production Plant 694,904,473.45 2.27 15,767,090 Other Production Plant 327,546,910.58 3.09 10,124,666 Transmission Plant 948,182,505.39 2.32 21,986,055 Distribution Plant 2,081,784,379.62 2.55 53,141,642 General Plant 166,852,916.86 4.64 7,738,766 Total Electric Plant 4,664,358,358.02 2.74 127,953,839 GAS PLANT - Washington and Idaho Natural Gas Storage and Processing Plant 47,265,475.76 1.51 713,563 Distribution Plant 889,754,251.07 2.41 21,414,569 General Plant 50,261,857.69 3.28 1,648,085 Total Gas Plant - Washington and Idaho 987,281,584.52 2.41 23,776,217 GAS PLANT - Allocated All General Plant 6,617,857.53 5.90 390,484 GAS PLANT - Oregon Natural Gas Storage and Processing Plant 7,180,697.93 1.85 132,599 Distribution Plant 469,227,390.41 2.30 10,771,102 General Plant 10,642,537.06 4.43 471,417 Total Gas Plant - Oregon 487,050,625.40 2.34 11,375,118 COMMON PLANT General Plant 395,947,482.60 6.96 27,541,449 Total Common Plant 395,947,482.60 6.96 27,541,449 UNRECOVERED RESERVE Electric Plant - 310,780 Gas Plant - Washington and Idaho - (2,269) Gas Plant - Allocated All - (23,622) Gas Plant - Oregon - (81,582) Common Plant - (1,445,958) Total Unrecovered Reserve (1,242,651) Total Electric, Gas, and Common Depreciable Plant 6,541,255,908.07 2.90 189,794,456 _____________________________________________________________________________________________ Avista Corporation December 31, 2021LY Attachment C J. Spanos, Avista Page 7 of 800 PART I. INTRODUCTION _____________________________________________________________________________________________ Avista Corporation December 31, 2021I-1 Attachment C J. Spanos, Avista Page 8 of 800 AVISTA CORPORATION DEPRECIATION STUDY PART I. INTRODUCTION SCOPE This report sets forth the results of the depreciation study for Avista Corporation (“Avista”), to determine the annual depreciation accrual rates and amounts for book purposes applicable to the original cost of electric, gas and common plant as of December 31, 2021. The rates and amounts determined as a result of this study are based on the straight line remaining life method of depreciation. This report also describes the concepts, methods and judgments which underlie the recommended annual depreciation accrual rates related to electric, gas and common plant in service as of December 31, 2021. The service life and net salvage estimates resulting from the study were based on informed judgment which incorporated analyses of historical plant retirement data as recorded through 2021, a review of Company practice and outlook as they relate to plant operation and retirement, and consideration of current practice in the electric and gas industry, including knowledge of service lives and net salvage estimates used for other electric and gas companies. PLAN OF REPORT Part I, Introduction, contains statements with respect to the plan of the report, and the basis of the study. Part II, Estimation of Survivor Curves, presents the methods used in the service life analyses. Part III, Service Life Considerations, presents the factors and judgment utilized in the service life study. Part IV, Net Salvage Considerations, presents the judgment utilized for the net salvage study. Part V, Calculation of Annual and Accrued Depreciation, describes the procedures used in the calculation of group depreciation. Part _____________________________________________________________________________________________ Avista Corporation December 31, 2021I-2 Attachment C J. Spanos, Avista Page 9 of 800 VI, Results of Study, presents a summary by depreciable group of annual depreciation accrual rates and amounts, as well as composite remaining lives. Part VII, Service Life Statistics presents the statistical analysis of service life estimates, Part VIII, Net Salvage Statistics sets forth the statistical indications of net salvage percents, and Part IX, Detailed Depreciation Calculations presents the detailed tabulations of annual depreciation. BASIS OF THE STUDY Depreciation Depreciation, in public utility regulation, is the loss in service value not restored by current maintenance, incurred in connection with the consumption or prospective retirement of utility plant in the course of service from causes which are known to be in current operation and against which the utility is not protected by insurance. Among causes to be given consideration are wear and tear, deterioration, action of the elements, inadequacy, obsolescence, changes in the art, changes in demand, and the requirements of public authorities. Depreciation, as used in accounting, is a method of distributing fixed capital costs, less net salvage, over a period of time by allocating annual amounts to expense. Each annual amount of such depreciation expense is part of that year's total cost of providing utility service. Normally, the period of time over which the fixed capital cost is allocated to the cost of service is equal to the period of time over which an item renders service, that is, the item's service life. The most prevalent method of allocation is to distribute an equal amount of cost to each year of service life. This method is known as the straight- line method of depreciation. For most accounts, the annual depreciation was calculated by the straight line method using the average service life procedure and the remaining life basis. For certain General Plant accounts, the annual depreciation is based on amortization accounting. _____________________________________________________________________________________________ Avista Corporation December 31, 2021I-3 Attachment C J. Spanos, Avista Page 10 of 800 Both types of calculations were based on original cost, attained ages, and estimates of service lives and net salvage. The straight line method, average service life procedure is a commonly used depreciation calculation procedure that has been widely accepted in jurisdictions throughout North America. Gannett Fleming recommends its continued use in this study. Amortization accounting is used for certain General Plant accounts because of the disproportionate plant accounting effort required when compared to the minimal original cost of the large number of items in these accounts. An explanation of the calculation of annual and accrued amortization is presented beginning on page V-4 of the report. Service Life and Net Salvage Estimates The service life and net salvage estimates used in the depreciation and amortization calculations were based on informed judgment which incorporated a review of management’s plans, policies and outlook, a general knowledge of the electric and gas utility industry, and comparisons of the service life and net salvage estimates from our studies of other electric and gas utilities. The use of survivor curves to reflect the expected dispersion of retirement provides a consistent method of estimating depreciation for utility plant. Iowa type survivor curves were used to depict the estimated survivor curves for the plant accounts not subject to amortization accounting. The procedure for estimating service lives consisted of compiling historical data for the plant accounts or depreciable groups, analyzing this history through the use of widely accepted techniques, and forecasting the survivor characteristics for each depreciable group on the basis of interpretations of the historical data analyses and the probable future. The combination of the historical experience and estimates of future experience yielded estimated survivor curves from which the average service lives were derived. _____________________________________________________________________________________________ Avista Corporation December 31, 2021I-4 Attachment C J. Spanos, Avista Page 11 of 800 PART II. ESTIMATION OF SURVIVOR CURVES _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-1 Attachment C J. Spanos, Avista Page 12 of 800 PART II. ESTIMATION OF SURVIVOR CURVES The calculation of annual depreciation based on the straight line method requires the estimation of survivor curves and the selection of group depreciation procedures. The estimation of survivor curves is discussed below and the development of net salvage is discussed in later sections of this report. SURVIVOR CURVES The use of an average service life for a property group implies that the various units in the group have different lives. Thus, the average life may be obtained by determining the separate lives of each of the units or by constructing a survivor curve by plotting the number of units which survive at successive ages. The survivor curve graphically depicts the amount of property existing at each age throughout the life of an original group. From the survivor curve, the average life of the group, the remaining life expectancy, the probable life, and the frequency curve can be calculated. In Figure 1, a typical smooth survivor curve and the derived curves are illustrated. The average life is obtained by calculating the area under the survivor curve, from age zero to the maximum age, and dividing this area by the ordinate at age zero. The remaining life expectancy at any age can be calculated by obtaining the area under the curve, from the observation age to the maximum age, and dividing this area by the percent surviving at the observation age. For example, in Figure 1, the remaining life at age 30 is equal to the crosshatched area under the survivor curve divided by 29.5 percent surviving at age 30. The probable life at any age is developed by adding the age and remaining life. If the probable life of the property is calculated for each year of age, the probable life curve shown in the chart can be developed. The frequency curve presents the number of units retired in each age interval. It is derived by obtaining the differences between the amount of property surviving at the beginning and at the end of each interval. _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-2 Attachment C J. Spanos, Avista Page 13 of 800 This study has incorporated the use of Iowa curves developed from a retirement rate analysis of historical retirement history. A discussion of the concepts of survivor curves and of the development of survivor curves using the retirement rate method is presented below. Iowa Type Curves The range of survivor characteristics usually experienced by utility and industrial properties is encompassed by a system of generalized survivor curves known as the Iowa type curves. There are four families in the Iowa system, labeled in accordance with the location of the modes of the retirements (or the portion of the frequency curve with the highest level of retirements) in relationship to the average life and the relative height of the modes. The left moded curves, presented in Figure 2, are those in which the greatest frequency of retirement occurs to the left of, or prior to, average service life. The symmetrical moded curves, presented in Figure 3, are those in which the greatest frequency of retirement occurs at average service life. The right moded curves, presented in Figure 4, are those in which the greatest frequency occurs to the right of, or after, average service life. The origin moded curves, presented in Figure 5, are those in which the greatest frequency of retirement occurs at the origin, or immediately after age zero. The letter designation of each family of curves (L, S, R or O) represents the location of the mode of the associated frequency curve with respect to the average service life. The numbers represent the relative heights of the modes of the frequency curves within each family. A higher number designates a higher mode curve. The Iowa curves were developed at the Iowa State College Engineering Experiment Station through an extensive process of observation and classification of the ages at which industrial property had been retired. A report of the study which resulted in the classification of property survivor characteristics into 18 type curves, which constitute three of the four families, was published in 1935 in the form of the Experiment Station’s Bulletin 125. _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-3 Attachment C J. Spanos, Avista Page 14 of 800 0102030405060708090 10 0 0 5 1 0 1 5 2 0 2 5 3 0 3 5 4 0 4 5 5 0 5 5 6 0 Percent Surviving Ag e i n Y e a r s Av e r a g e L i f e Ma x i m u m L i f e Pr o b a b l e L i f e Ag e Ex p e c t a n c y Su r v i v o r C u r v e Pr o b a b l e L i f e C u r v e Fr e q u e n c y C u r v e Mo d e FI G 85 (  1. 7 < 3 , & $ /  6 8 5 9 , 9 2 5  & 8 5 9 (  $ ND D (5 , 9 ( D &8 5 9 ( 6 _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-4 Attachment C J. Spanos, Avista Page 15 of 800 L0 L1 L2 L3 L4 L5 0102030405060708090 10 0 0 2 5 5 0 7 5 1 0 0 1 2 5 1 5 0 1 7 5 2 0 0 2 2 5 2 5 0 2 7 5 3 0 0 Percent Surviving Ag e , P e r c e n t o f A v e r a g e L i f e L0 L1L2 L3 L4 L5 05101520253035404550 0 2 5 5 0 7 5 1 0 0 1 2 5 1 5 0 1 7 5 2 0 0 2 2 5 2 5 0 2 7 5 3 0 0 Frequency, Percent for 10 Percent Intervals Ag e , P e r c e n t o f A v e r a g e L i f e F,G85 ( . / ( F7 0 2 D$/  2 5   /   , 2 : $  7 < 3 (  6 8 5 9 , 9 2 5  & 8 5 9 ( 6 _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-5 Attachment C J. Spanos, Avista Page 16 of 800 S0 S1 S2 S3 S4 S5 S6 0102030405060708090 10 0 0 2 5 5 0 7 5 1 0 0 1 2 5 1 5 0 1 7 5 2 0 0 2 2 5 2 5 0 2 7 5 3 0 0 Percent Surviving Ag e , P e r c e n t o f A v e r a g e L i f e S0 S1 S2 S3S4 S5 S6 05101520253035404550 0 2 5 5 0 7 5 1 0 0 1 2 5 1 5 0 1 7 5 2 0 0 2 2 5 2 5 0 2 7 5 3 0 0 Frequency,Percentfor10PercentIntervals Ag e , P e r c e n t o f A v e r a g e L i f e FI G 85 (   . 6 < 0 0 ( 7 5 , & $ /  2 5   6  ,2 : $  7 < 3 (  6 8 5 9 , 9 2 5  & 8 5 9 ( 6 _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-6 Attachment C J. Spanos, Avista Page 17 of 800 R1 R2 R3 R4 R5 0102030405060708090 10 0 0 2 5 5 0 7 5 1 0 0 1 2 5 1 5 0 1 7 5 2 0 0 2 2 5 2 5 0 2 7 5 3 0 0 Percent Surviving Ag e , P e r c e n t o f A v e r a g e L i f e R1R2R3R4 R5 05101520253035404550 0 2 5 5 0 7 5 1 0 0 1 2 5 1 5 0 1 7 5 2 0 0 2 2 5 2 5 0 2 7 5 3 0 0 Frequency, Percent for 10 Percent Intervals Ag e , P e r c e n t o f A v e r a g e L i f e FI G 85 (   . 5 , * + 7  0 2 ' $ /  2 5   5   , 2 : $  7 < 3 (  6 8 5 9 , 9 2 5  & 8 5 9 ( 6 _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-7 Attachment C J. Spanos, Avista Page 18 of 800 O1 O2 O3 O4 0102030405060708090 10 0 0 2 5 5 0 7 5 1 0 0 1 2 5 1 5 0 1 7 5 2 0 0 2 2 5 2 5 0 2 7 5 3 0 0 Percent Surviving Ag e , P e r c e n t o f A v e r a g e L i f e O1 O2 O3 O4 02468101214161820 0 2 5 5 0 7 5 1 0 0 1 2 5 1 5 0 1 7 5 2 0 0 2 2 5 2 5 0 2 7 5 3 0 0 Frequency, Percent for 10 Percent Intervals Ag e , P e r c e n t o f A v e r a g e L i f e FI G U R E 5 . 25 , * , 1  0 2 ' $ /  2 5   2   , 2 : $  7 < 3 (  6 8 5 9 , 9 2 5  & 8 5 9 ( 6 _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-8 Attachment C J. Spanos, Avista Page 19 of 800 These curve types have also been presented in subsequent Experiment Station bulletins and in the text, "Engineering Valuation and Depreciation."1 In 1957, Frank V. B. Couch, Jr., an Iowa State College graduate student, submitted a thesis presenting his development of the fourth family consisting of the four O type survivor curves. Retirement Rate Method of Analysis The retirement rate method is an actuarial method of deriving survivor curves using the average rates at which property of each age group is retired. The method relates to property groups for which aged accounting experience is available and is the method used to develop the original stub survivor curves in this study. The method (also known as the annual rate method) is illustrated through the use of an example in the following text and is also explained in several publications including "Statistical Analyses of Industrial Property Retirements,"2 "Engineering Valuation and Depreciation,"3 and "Depreciation Systems."4 The average rate of retirement used in the calculation of the percent surviving for the survivor curve (life table) requires two sets of data: first, the property retired during a period of observation, identified by the property's age at retirement; and second, the property exposed to retirement at the beginning of the age intervals during the same period. The period of observation is referred to as the experience band. The band of years which represent the installation dates of the property exposed to retirement during the experience band is referred to as the placement band. An example of the calculations used in the development of a life table follows. The example includes schedules of annual aged property transactions, a schedule of plant exposed to retirement, a life table and illustrations of smoothing the stub survivor curve. 1Marston, Anson, Robley Winfrey and Jean C. Hempstead. Engineering Valuation and Depreciation, 2nd Edition. New York, McGraw-Hill Book Company. 1953. 2Winfrey, Robley, Statistical Analyses of Industrial Property Retirements. Iowa State College, Engineering Experiment Station, Bulletin 125. 1935. 3Marston, Anson, Robley Winfrey, and Jean C. Hempstead, Supra Note 1. 4Wolf, Frank K. and W. Chester Fitch. Depreciation Systems. Iowa State University Press. 1994. _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-9 Attachment C J. Spanos, Avista Page 20 of 800 Schedules of Annual Transactions in Plant Records The property group used to illustrate the retirement rate method is observed for the experience band 2012-2021 for which there were placements during the years 2007- 2021. In order to illustrate the summation of the aged data by age interval, the data were compiled in the manner presented in Schedules 1 and 2 on pages II-11 and II-12. In Schedule 1, the year of installation (year placed) and the year of retirement are shown. The age interval during which a retirement occurred is determined from this information. In the example which follows, $10,000 of the dollars invested in 2007 were retired in 2012. The $10,000 retirement occurred during the age interval between 4½ and 5½ years on the basis that approximately one-half of the amount of property was installed prior to and subsequent to July 1 of each year. That is, on the average, property installed during a year is placed in service at the midpoint of the year for the purpose of the analysis. All retirements also are stated as occurring at the midpoint of a one-year age interval of time, except the first age interval which encompasses only one-half year. The total retirements occurring in each age interval in a band are determined by summing the amounts for each transaction year-installation year combination for that age interval. For example, the total of $143,000 retired for age interval 4½-5½ is the sum of the retirements entered on Schedule 1 immediately above the stair step line drawn on the table beginning with the 2012 retirements of 2007 installations and ending with the 2021 retirements of the 2016 installations. Thus, the total amount of 143 for age interval 4½- 5½ equals the sum of: 10 + 12 + 13 + 11 + 13 + 13 + 15 + 17 + 19 + 20. _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-10 Attachment C J. Spanos, Avista Page 21 of 800 Ye a r To t a l D u r i n g A g e Pl a c e d 20 1 2 20 1 3 20 1 4 20 1 5 20 1 6 20 1 7 20 1 8 20 1 9 20 2 0 20 2 1 Ag e I n t e r v a l I n t e r v a l 1 2 3 4 5 6 7 8 9 10 11 12 13 20 0 7 1 0 1 1 1 2 1 3 1 4 1 6 2 3 2 4 2 5 2 6 26 1 3 ½ - 1 4 ½ 20 0 8 1 1 1 2 1 3 1 5 1 6 1 8 2 0 2 1 2 2 1 9 44 1 2 ½ - 1 3 ½ 20 0 9 1 1 1 2 1 3 1 4 1 6 1 7 1 9 2 1 2 2 1 8 64 1 1 ½ - 1 2 ½ 20 1 0 8 9 1 0 1 1 1 1 1 3 1 4 1 5 1 6 1 7 83 1 0 ½ - 1 1 ½ 20 1 1 9 1 0 1 1 1 2 1 3 1 4 1 6 1 7 1 9 2 0 9 3 9 ½ - 1 0 ½ 20 1 2 4 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 2 0 1 0 5 8½ - 9 ½ 20 1 3 5 1 1 1 2 1 3 1 4 1 5 1 6 1 8 2 0 1 1 3 7½ - 8 ½ 20 1 4 6 1 2 1 3 1 5 1 6 1 7 1 9 1 9 1 2 4 6½ - 7 ½ 20 1 5 6 1 3 1 5 1 6 1 7 1 9 1 9 1 3 1 5½ - 6 ½ 20 1 6 7 1 4 1 6 1 7 1 9 2 0 1 4 3 4½ - 5 ½ 20 1 7 8 1 8 2 0 2 2 2 3 1 4 6 3½ - 4 ½ 20 1 8 9 2 0 2 2 2 5 1 5 0 2½ - 3 ½ 20 1 9 11 2 3 2 5 1 5 1 1½ - 2 ½ 20 2 0 11 2 4 1 5 3 ½- 1 ½ 20 2 1 13 80 0- ½ To t a l 53 6 8 8 6 1 0 6 1 2 8 1 5 7 1 9 6 2 3 1 2 7 3 3 0 8 1 , 6 0 6 Re t i r e m e n t s , T h o u s a n d s o f D o l l a r s Du r i n g Y e a r SC H E D U L E 1 . R E T I R E M E N T S F O R E A C H Y E A R 2 0 1 2 - 2 0 2 1 SU M M A R I Z E D B Y A G E I N T E R V A L E x p e r i e n c e B a n d 2 0 1 2 - 2 0 2 1 Pl a c e m e n t B a n d 2 0 0 7 - 2 0 2 1 _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-11 Attachment C J. Spanos, Avista Page 22 of 800 Ex p e r i e n c e B a n d 2 0 1 2 - 2 0 2 1 P l a c e m e n t B a n d 2 0 0 7 - 2 0 2 1 Ye a r To t a l D u r i n g A g e Pl a c e d 20 1 2 20 1 3 20 1 4 20 1 5 20 1 6 20 1 7 20 1 8 20 1 9 20 2 0 20 2 1 ge I n t e r v a l In t e r v a l (1 ) (2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) ( 8 ) ( 9 ) ( 1 0 ) ( 1 1 ) ( 1 2 ) ( 1 3 ) 20 0 7 - - - - - - 60 a - - - - 1 3 ½ - 1 4 ½ 20 0 8 - - - - - - - - - - - 1 2 ½ - 1 3 ½ 20 0 9 - - - - - - - - - - - 1 1 ½ - 1 2 ½ 20 1 0 - - - - - - - (5 ) b - - 60 1 0 ½ - 1 1 ½ 20 1 1 - - - - - - - 6a - - - 9 ½ - 1 0 ½ 20 1 2 - - - - - - - - - - (5 ) 8 ½ - 9 ½ 20 1 3 - - - - - - - - - 6 7½ - 8 ½ 20 1 4 - - - - - - - - - 6 ½ - 7 ½ 20 1 5 - - - - (1 2 ) b - - - 5 ½ - 6 ½ 20 1 6 - - - - 22 a - - 4 ½ - 5 ½ 20 1 7 - - (1 9 ) b - - 10 3 ½ - 4 ½ 20 1 8 - - - - - 2 ½ - 3 ½ 20 1 9 - - (1 0 2 ) c (1 2 1 ) 1 ½ - 2 ½ 20 2 0 - - - ½ - 1 ½ 20 2 1 - 0 - ½ To t a l - - - - - - 6 0 ( 3 0 ) 2 2 ( 10 2 ) ( 5 0 ) a T r a n s f e r A f f e c t i n g E x p o s u r e s a t B e g i n n i n g o f Y e a r T r a n s f e r A f f e c t i n g E x p o s u r e s a t E n d o f Y e a r c S a l e w i t h C o n t i n u e d U s e P a r e n t h e s e s D e n o t e C r e d i t A m o u n t . Ac q u i s i t i o n s , T r a n s f e r s a n d S a l e s , T h o u s a n d s o f D o l l a r s Du r i n g Y e a r SC H E D U L E 2 . O T H E R T R A N S A C T I O N S F O R E A C H Y E A R 2 0 1 2 - 2 0 2 1 SU M M A R I Z E D B Y A G E I N T E R V A L _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-12 Attachment C J. Spanos, Avista Page 23 of 800 In Schedule 2, other transactions which affect the group are recorded in a similar manner. The entries illustrated include transfers and sales. The entries which are credits to the plant account are shown in parentheses. The items recorded on this schedule are not totaled with the retirements, but are used in developing the exposures at the beginning of each age interval. Schedule of Plant Exposed to Retirement The development of the amount of plant exposed to retirement at the beginning of each age interval is illustrated in Schedule 3 on page II-14. The surviving plant at the beginning of each year from 2012 through 2021 is recorded by year in the portion of the table headed "Annual Survivors at the Beginning of the Year." The last amount entered in each column is the amount of new plant added to the group during the year. The amounts entered in Schedule 3 for each successive year following the beginning balance or addition are obtained by adding or subtracting the net entries shown on Schedules 1 and 2. For the purpose of determining the plant exposed to retirement, transfers-in are considered as being exposed to retirement in this group at the beginning of the year in which they occurred, and the sales and transfers-out are considered to be removed from the plant exposed to retirement at the beginning of the following year. Thus, the amounts of plant shown at the beginning of each year are the amounts of plant from each placement year considered to be exposed to retirement at the beginning of each successive transaction year. For example, the exposures for the installation year 2017 are calculated in the following manner: Exposures at age 0 = amount of addition = $750,000 Exposures at age ½ = $750,000 - $ 8,000 = $742,000 Exposures at age 1½ = $742,000 - $18,000 = $724,000 Exposures at age 2½ = $724,000 - $20,000 - $19,000 = $685,000 Exposures at a e 3½ = $685,000 - $22,000 = $663,000 _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-13 Attachment C J. Spanos, Avista Page 24 of 800 To t a l a t Ye a r Be g i n n i n g o f A g e Pl a c e d 20 1 2 20 1 3 20 1 4 20 1 5 20 1 6 20 1 7 20 1 8 20 1 9 20 2 0 20 2 1 Ag e I n t e r v a l I n t e r v a l (1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) ( 8 ) ( 9 ) ( 1 0 ) ( 1 1 ) ( 1 2 ) ( 1 3 ) 20 0 7 2 5 5 2 4 5 2 3 4 2 2 2 2 0 9 1 9 5 2 3 9 2 1 6 1 9 2 1 6 7 1 6 7 1 3 ½ - 1 4 ½ 20 0 8 2 7 9 2 6 8 2 5 6 2 4 3 2 2 8 2 1 2 1 9 4 1 7 4 1 5 3 1 3 1 3 2 3 1 2 ½ - 1 3 ½ 20 0 9 3 0 7 2 9 6 2 8 4 2 7 1 2 5 7 2 4 1 2 2 4 2 0 5 1 8 4 1 6 2 5 3 1 1 1 ½ - 1 2 ½ 20 1 0 3 3 8 3 3 0 3 2 1 3 1 1 3 0 0 2 8 9 2 7 6 2 6 2 2 4 2 2 2 6 8 2 3 1 0 ½ - 1 1 ½ 20 1 1 3 7 6 3 6 7 3 5 7 3 4 6 3 3 4 3 2 1 3 0 7 2 9 7 2 8 0 2 6 1 1 , 0 9 7 9 ½ - 1 0 ½ 20 1 2   ୹ 41 6 4 0 7 3 9 7 3 8 6 3 7 4 3 6 1 3 4 7 3 3 2 3 1 6 1 , 5 0 3 8 ½ - 9 ½ 20 1 3   ୹ 45 5 4 4 4 4 3 2 4 1 9 4 0 5 3 9 0 3 7 4 3 5 6 1 , 9 5 2 7 ½ - 8 ½ 20 1 4   ୹ 50 4 4 9 2 4 7 9 4 6 4 4 4 8 4 3 1 4 1 2 2 , 4 6 3 6 ½ - 7 ½ 20 1 5   ୹ 57 4 5 6 1 5 4 6 5 3 0 5 0 1 4 8 2 3 , 0 5 7 5 ½ - 6 ½ 20 1 6   ୹ 65 3 6 3 9 6 2 3 6 2 8 6 0 9 3 , 7 8 9 4 ½ - 5 ½ 20 1 7   ୹ 74 2 7 2 4 6 8 5 6 6 3 4 , 3 3 2 3 ½ - 4 ½ 20 1 8   ୹ 84 1 8 2 1 7 9 9 4 , 9 5 5 2 ½ - 3 ½ 20 1 9   ୹ 94 9 9 2 6 5 , 7 1 9 1 ½ - 2 ½ 20 2 0         ୹ 1, 0 6 9 6 , 5 7 9 ½ - 1 ½ 20 2 1        ୹ 7 , 4 9 0 0 - ½ To t a l 1, 9 7 5 2, 3 8 2 2, 8 2 4 3, 3 1 8 3, 8 7 2 4, 4 9 4 5, 2 4 7 6, 0 1 7 6, 8 5 2 7, 7 9 9 4 4 , 7 8 0 ୹$ G G L W L R Q V  G X U L Q J  W K H  \ H D U Ex p o s u r e s , T h o u s a n d s o f D o l l a r s An n u a l S u r v i v o r s a t t h e B e g i n n i n g o f t h e Y e a r JA N U A R Y 1 O F E A C H Y E A R 2 0 1 2 - 2 0 2 1 SC H E D U L E 3 . P L A N T E X P O S E D T O R E T I R E M E N T SU M M A R I Z E D B Y A G E I N T E R V A L E x p e r i e n c e B a n d 2 0 1 2 - 2 0 2 1 Pl a c e m e n t B a n d 2 0 0 7 - 2 0 2 1 _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-14 Attachment C J. Spanos, Avista Page 25 of 800 For the entire experience band 2012-2021, the total exposures at the beginning of an age interval are obtained by summing diagonally in a manner similar to the summing of the retirements during an age interval (Schedule 1). For example, the figure of 3,789, shown as the total exposures at the beginning of age interval 4½-5½, is obtained by summing: 255 + 268 + 284 + 311 + 334 + 374 + 405 + 448 + 501 + 609. Original Life Table The original life table, illustrated in Schedule 4 on page II-16, is developed from the totals shown on the schedules of retirements and exposures, Schedules 1 and 3, respectively. The exposures at the beginning of the age interval are obtained from the corresponding age interval of the exposure schedule, and the retirements during the age interval are obtained from the corresponding age interval of the retirement schedule. The retirement ratio is the result of dividing the retirements during the age interval by the exposures at the beginning of the age interval. The percent surviving at the beginning of each age interval is derived from survivor ratios, each of which equals one minus the retirement ratio. The percent surviving is developed by starting with 100% at age zero and successively multiplying the percent surviving at the beginning of each interval by the survivor ratio, i.e., one minus the retirement ratio for that age interval. The calculations necessary to determine the percent surviving at age 5½ are as follows: The totals of the exposures and retirements (columns 2 and 3) are shown for the purpose of checking with the respective totals in Schedules 1 and 3. The ratio of the total retirements to the total exposures, other than for each age interval, is meaningless. Percent surviving at age 4½ = 88.15 Exposures at age 4½ = 3,789,000 Retirements from age 4½ to 5½ = 143,000 Retirement Ratio = 143,000 ÷ 3,789,000 = 0.0377 Survivor Ratio = 1.000 - 0.0377 = 0.9623 Percent survivin at a e 5½ = 88.15 x 0.9623 = 84.83 _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-15 Attachment C J. Spanos, Avista Page 26 of 800 SCHEDULE 4. ORIGINAL LIFE TABLE CALCULATED BY THE RETIREMENT RATE METHOD Experience Band 2012-2021 Placement Band 2007-2021 Exposure and Retirement Amounts are in Thousands of Dollars Age at Beginning of Interval Exposures at Beginning of Age Interval Retirements During Age Interval Retirement Ratio Survivor Ratio Percent Surviving at Beginning of Age Interval 1 2 3 4 5 6 0.0 7,490 80 0.0107 0.9893 100.00 0.5 6,579 153 0.0233 0.9767 98.93 1.5 5,719 151 0.0264 0.9736 96.62 2.5 4,955 150 0.0303 0.9697 94.07 3.5 4,332 146 0.0337 0.9663 91.22 4.5 3,789 143 0.0377 0.9623 88.15 5.5 3,057 131 0.0429 0.9571 84.83 6.5 2,463 124 0.0503 0.9497 81.19 7.5 1,952 113 0.0579 0.9421 77.11 8.5 1,503 105 0.0699 0.9301 72.65 9.5 1,097 93 0.0848 0.9152 67.57 10.5 823 83 0.1009 0.8991 61.84 11.5 531 64 0.1205 0.8795 55.60 12.5 323 44 0.1362 0.8638 48.90 13.5 167 26 0.1557 0.8443 42.24 35.66 Total 44,780 1,606 Column 2 from Schedule 3, Column 12, Plant Exposed to Retirement. Column 3 from Schedule 1, Column 12, Retirements for Each Year. Column 4 = Column 3 Divided by Column 2. Column 5 = 1.0000 Minus Column 4. Column 6 = Column 5 Multiplied by Column 6 as of the Preceding Age Interval. _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-16 Attachment C J. Spanos, Avista Page 27 of 800 The original survivor curve is plotted from the original life table (column 6, Schedule 4). When the curve terminates at a percent surviving greater than zero, it is called a stub survivor curve. Survivor curves developed from retirement rate studies generally are stub curves. Smoothing the Original Survivor Curve The smoothing of the original survivor curve eliminates any irregularities and serves as the basis for the preliminary extrapolation to zero percent surviving of the original stub curve. Even if the original survivor curve is complete from 100% to zero percent, it is desirable to eliminate any irregularities, as there is still an extrapolation for the vintages which have not yet lived to the age at which the curve reaches zero percent. In this study, the smoothing of the original curve with established type curves was used to eliminate irregularities in the original curve. The Iowa type curves are used in this study to smooth those original stub curves which are expressed as percents surviving at ages in years. Each original survivor curve was compared to the Iowa curves using visual and mathematical matching in order to determine the better fitting smooth curves. In Figures 6, 7, and 8, the original curve developed in Schedule 4 is compared with the L, S, and R Iowa type curves which most nearly fit the original survivor curve. In Figure 6, the L1 curve with an average life between 12 and 13 years appears to be the best fit. In Figure 7, the S0 type curve with a 12-year average life appears to be the best fit and appears to be better than the L1 fitting. In Figure 8, the R1 type curve with a 12-year average life appears to be the best fit and appears to be better than either the L1 or the S0. In Figure 9, the three fittings, 12-L1, 12-S0 and 12-R1 are drawn for comparison purposes. It is probable that the 12-R1 Iowa curve would be selected as the most representative of the plotted survivor characteristics of the group. _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-17 Attachment C J. Spanos, Avista Page 28 of 800 FI G U R E 6 . I L L U S T R A T I O N O F T H E M A T C H I N G O F A N O R I G I N A L S U R V I V O R C U R V E W I T H A N L 1 I O W A T Y P E C U R V E OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-18 Attachment C J. Spanos, Avista Page 29 of 800 FI G U R E 7 . I L L U S T R A T I O N O F T H E M A T C H I N G O F A N O R I G I N A L S U R V I V O R C U R V E W I T H A N S 0 I O W A T Y P E C U R V E OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-19 Attachment C J. Spanos, Avista Page 30 of 800 FI G U R E 8 . I L L U S T R A T I O N O F T H E M A T C H I N G O F A N O R I G I N A L S U R V I V O R C U R V E W I T H A N R 1 I O W A T Y P E C U R V E OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-20 Attachment C J. Spanos, Avista Page 31 of 800 FI G U R E 9 . I L L U S T R A T I O N O F T H E M A T C H I N G O F A N O R I G I N A L S U R V I V O R C U R V E W I T H A N L 1 , S 0 A N D R 1 I O W A T Y P E C U R V E OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021II-21 Attachment C J. Spanos, Avista Page 32 of 800 PART III. SERVICE LIFE CONSIDERATIONS _____________________________________________________________________________________________ Avista Corporation December 31, 2021III-1 Attachment C J. Spanos, Avista Page 33 of 800 PART III. SERVICE LIFE CONSIDERATIONS FIELD TRIPS In order to be familiar with the operation of the Company and observe representative portions of the plant, a field trip was conducted for the study. A general understanding of the function of the plant and information with respect to the reasons for past retirements and the expected future causes of retirements are obtained during field trips. This knowledge and information were incorporated in the interpretation and extrapolation of the statistical analyses. The following is a list of the locations visited during the most recent field trips. November 30 - December 1, 2021 Kettle Falls Generating Station Long Lake Hydro Plant Little Falls Hydro Plant Monroe Street Hydro Plant August 9, 2017 Noxon Rapids Hydro Plant Cabinet Gorge Hydro Plant July 11-13, 2017 Long Lake Hydro Plant Little Falls Hydro Plant Millwood Substation Opportunity Substation Green Acres Substation Boulder Park Substation Boulder Park Generating Station Avista Headquarters and Central Operations Facility Downtown Campus Nine Mile City Gate Station Francis Avenue and Cannon Street Regulating Station #1763 Kaiser-Trentwood Regulating Station Country Vista Drive and Henry Road Regulating Station #1787 Chase Road City Gate Station _____________________________________________________________________________________________ Avista Corporation December 31, 2021III-2 Attachment C J. Spanos, Avista Page 34 of 800 September 14, 2011 Colstrip Generating Station Rosebud Mine March 9-11, 2011 Kettle Falls Generating Station Mica City Gate Station Barker Bridge Crossing Idaho and 4th Street Regulating Station #217 Post Falls Hydro Plant Idaho Road Substation Spokane Customer Service Center Post Street Substation Upper Falls Hydro Plant Monroe Street Hydro Plant Nine Mile Falls Gate and Regulating Station West Side Substation Nine Mile Hydro Plant Nine Mile Substation Indian Trail Substation Central Operations Facility May 24, 2005 Rathdrum CT Facility Rathdum Substation Boekel Road City Gate Station #600 Boekel Road City Gate Station #210 Post Falls Hydro Plant April 4-6, 2005 Decatur and Crestline Regulating Station #12 Crestline and Lincoln Road Regulating Station #718 Mead City Gate Station Freya Station #17 Freya and Lincoln Regulating Station #76 Dollar Road Operations Center Noxon Rapids Hydro Plant Noxon Rapids Substation Cabinet Gorge Hydro Plant Cabinet Gorge Substation Coyote Springs CT Plant Boulder Park Generating Station Boulder Park Substation Ross Park Substation _____________________________________________________________________________________________ Avista Corporation December 31, 2021III-3 Attachment C J. Spanos, Avista Page 35 of 800 SERVICE LIFE ANALYSIS The service life estimates were based on informed judgment which considered a number of factors. The primary factors were the statistical analyses of data; current Company policies and outlook as determined during conversations with management; and the survivor curve estimates from previous studies of this company and other electric and gas companies. For many of the plant accounts and subaccounts for which survivor curves were estimated, the statistical analyses using the retirement rate method resulted in reasonable indications of the survivor patterns experienced. These accounts represent 72 percent of depreciable plant. Generally, the information external to the statistics led to little or no significant departure from the indicated survivor curves for the accounts listed below. The statistical support for the service life estimates is presented in the section beginning on page VII-2. Account No. Account Description ELECTRIC PLANT Steam Production Plant 311.00 Structures and Improvements 312.00 Boiler Plant Equipment 314.00 Turbogenerators 315.00 Accessory Electric Equipment 316.00 Miscellaneous Power Plant Equipment Hydro Production Plant 331.00 Structures and Improvements 333.00 Turbines and Generators 334.00 Accessory Electric Equipment 335.00 Miscellaneous Power Plant Equipment Other Production Plant 342.00 Fuel Holders, Producers and Accessories 345.00 Accessory Electric Equipment 346.00 Miscellaneous Power Plant Equipment Transmission Plant 352.00 Structures and Improvements 353.00 Station Equipment 355.00 Poles and Fixtures 358.00 Underground Conductors and Devices _____________________________________________________________________________________________ Avista Corporation December 31, 2021III-4 Attachment C J. Spanos, Avista Page 36 of 800 Distribution Plant 361.00 Structures and Improvements 362.00 Station Equipment 364.00 Poles, Towers and Fixtures 367.00 Underground Conductors and Devices 368.00 Line Transformers 369.10 Services – Overhead 369.20 Services – Underground - Spokane Network 369.30 Services – Underground - Other 370.10 Meters – Idaho 370.30 Meters – Washington Standard 373.10 Street Lighting & Signal Systems – Mercury Vapor 373.20 Street Lighting & Signal Systems – Underground Conductor 373.30 Street Lighting & Signal Systems – Decorative and Metal Standards 373.40 Street Lighting & Signal Systems – High Pressure Sodium Vapor 373.50 Street Lighting & Signal Systems – LED General Plant 390.10 Structures and Improvements – Company 392.20 Transportation Equipment – Light Trucks 392.30 Transportation Equipment – Medium Trucks 392.40 Transportation Equipment – Heavy Trucks 392.50 Transportation Equipment – Other 396.30 Power Operated Equipment – Medium Trucks 396.40 Power Operated Equipment – Heavy Trucks 396.50 Power Operated Equipment – Other GAS PLANT Natural Gas Storage and Processing Plant 354.00 Compressor Station Equipment 355.00 Measuring and Regulating Equipment 357.00 Other Equipment Distribution Plant 375.00 Structures and Improvements 376.00 Mains 378.00 Measuring and Regulating Equipment - General 379.00 Measuring and Regulating Equipment - City Gate 380.00 Services 381.00 Meters General Plant 390.10 Structures and Improvements – Company 392.20 Transportation Equipment – Light Trucks 392.30 Transportation Equipment – Medium Trucks 392.40 Transportation Equipment – Heavy Trucks 392.50 Transportation Equipment – Other 396.40 Power Operated Equipment – Heavy Trucks 396.50 Power Operated Equipment – Other _____________________________________________________________________________________________ Avista Corporation December 31, 2021III-5 Attachment C J. Spanos, Avista Page 37 of 800 COMMON PLANT 392.10 Transportation Equipment – Autos 392.20 Transportation Equipment – Light Trucks 392.30 Transportation Equipment – Medium Trucks 392.40 Transportation Equipment – Heavy Trucks 392.50 Transportation Equipment – Other 396.30 Power Operated Equipment – Medium Trucks 396.50 Power Operated Equipment – Other Electric Plant Account 353.00 Station Equipment, is used to illustrate the manner in which the study was conducted for the groups in the preceding list. Aged plant accounting data for the transmission plant originally owned by Avista Corporation have been compiled for the years 1989 through 2021. These data have been coded in the course of the Company's normal record keeping according to account or property group, type of transaction, year in which the transaction took place, and year in which the electric plant was placed in service. The retirements, other plant transactions, and plant additions were analyzed by the retirement rate method. The survivor curve estimate is based on the statistical indications for the period 1989 through 2021. The Iowa 46-R2 is a reasonable fit of the stub original survivor of station equipment. The 46-year service life is within the typical service life range of 40 to 55 years for station equipment. The 46-year life reflects the Company's plans to continue to upgrade equipment when necessary with expectations that some assets will be in service for a long time. The previous estimate for this account was a 44-R2 survivor curve. The determination of life characteristics for electric meters required different data analysis due to the classification of meters between Idaho and Washington. For Idaho meters, there is a program to convert to remote read meters by end of 2028. The remote read meters will have shorter life characteristics than the older standard meters. The _____________________________________________________________________________________________ Avista Corporation December 31, 2021III- Attachment C J. Spanos, Avista Page 38 of 800 assets in Account 370.1, Meters - Idaho , is best represented by the 33-L1.5 survivor curve and end of life date of 2028.. In Washington, the standard meters are placed in Account 370.3, Meters - Washington Standard and are best represented by the 12-L2.5 survivor curve which reflects the remaining life cycle for these meters. The relatively new meters in Account 370.4, Meters – Washington AMI have life characteristics best estimated by the 15-S2.5 Iowa curve. The life characteristics for gas meters did not require the same classification or revised analysis, as the replacement practices between the two jurisdictions and the types of meters will be comparable. However, the gas meters were segregated by state in this study. The 35- R1 survivor curve is a good fit of the historical indications and future expectations for most meters. There are new meters in Account 381.00, Metrers – Washington- AMI which represent new technology meters that will have a life of 15-S2.5 consistent with the comparable electric meters. The survivor curve estimate for Electric Account 364, Poles, Towers and Fixtures, is based on the statistical indications for the period 1989-2021. The Iowa 63-R3 is a reasonable fit of the original survivor curve. The 63-year service life is beyond the upper end of the typical service life range of 40 to 60 years for distribution poles. The 63-year life reflects the Company’s plans to replace poles consistently in the future as has been retired over the last thirty-three years. The previous estimate was a 65-R2.5 survivor curve. The survivor curve estimate for Electric Account 368, Line Transformers is the 50- R2.5 and is based on the statistical indication for the period 1989-2021. The previous estimate for this account is the 47-R2. Assets in this account primarily include _____________________________________________________________________________________________ Avista Corporation December 31, 2021III- Attachment C J. Spanos, Avista Page 39 of 800 transformers, both pole mounted and pad mounted. Retirements are often due to failure, but also occur due to upgrades required to meet the load. The 50-R2.5 represents a reasonable fit of the historical data through age 66, as shown on page VII-154 is consistent with management outlook for a continuation of the historical experience; and at the upper end of the typical range of service lives experienced for line transformers. Analysis for Account 380, Services, is used to provide an example for gas assets. The survivor curve estimate is the 52-R3 and is based on the statistical indications for the periods 1964-2021 and 2002-2021. The previous estimate for this account is the 50-R3. Assets in this account represents plastic, wrapped steel and bare steel services. Most retirements are due to changes in the associated mains, or leaks. The 52-R3 survivor curve sets forth a good fit of the historical data through age 63, as shown on page VII- 241, is consistent with management plans and within the typical 40-55 year range experienced for gas services. The statistical analyses for the foregoing plant accounts are presented in Part VII of the report. In addition, analyses are included for several accounts for which historical survivor curves are not yet definitive of the probable service life characteristics. These charts illustrate the historical experience to date against the anticipated life curve. Similar studies were performed for the remaining plant accounts. Each of the judgments represented a consideration of statistical analyses of aged plant activity, management’s outlook for the future, and the typical range of lives used by other electric and gas companies. The selected amortization periods for other General Plant accounts are described in the section “Calculated Annual and Accrued Amortization.” _____________________________________________________________________________________________ Avista Corporation December 31, 2021III- Attachment C J. Spanos, Avista Page 40 of 800 Life Span Estimates The life span method is appropriate for electric production facilities and some gas plant facilities in which all assets at the facility are expected to be retired concurrently upon the final retirement of the facility. The life span estimates for these facilities were based on current Company policies and outlook as determined during field review, discussions with management and the range of estimates from other electric and gas utility companies. Inasmuch as production plant consists of large generating units, the life span technique was employed in conjunction with the use of interim survivor curves which reflect interim retirements that occur prior to the ultimate retirement of the major unit. An interim survivor curve was estimated for each plant account, inasmuch as the rate of interim retirements differs from account to account. The interim survivor curves estimated were based on the retirement rate method of life analysis which incorporated experienced retirements for the period 1977 through 2021 for steam production plant, 1989 through 2021 for hydro production plant, and 1990 through 2021 for other production plant. The life span estimates for power generating stations were the result of considering experienced life spans of similar units, the age of survivor units, general operating characteristics of the units, major refurbishing, and discussions with management personnel concerning the probable long-term outlook for the units, and the estimate of the operating partner, if applicable. The life span estimate for the steam plant, base-load units are 39 to 55 years, which is on the lower end of the typical 50- to 60-year range of life spans expected for such units, however, in recent years steam facilities have been consistently retired with life spans of 45-50 years. These life spans represent the expected depreciable life of _____________________________________________________________________________________________ Avista Corporation December 31, 2021III- Attachment C J. Spanos, Avista Page 41 of 800 each facility under their current configuration. Future capital expenditures can extend a facility’s depreciable life, however, such changes to the depreciable life may not be prudent until the capital expenditures are actually put into plant in service. The life span for hydro facilities is based on the license or relicense date. A life span of 36-40 years was estimated for the majority of combustion turbines and combined cycle units. These life span estimates are typical for units which are used primarily as peaking units or load driven facilities. The life span for solar assets is 20 years which is within the industry range for similarly designed facilities. A summary of the major year in service, probable retirement date and life span for each unit follows: Probable Year in Retirement Depreciable Group Service Year Life Span Steam Production Plant Kettle Falls 1983 2038 55 Colstri 3 - Idaho 1984 2027 43 Colstri 4 - Idaho 1986 2027 41 Colstri 3 - Washin ton 1984 2025 41 Colstri 4 - Washin ton 1986 2025 39 H dro Production Plant Monroe Street 1992 2072 80 Little Falls 1910 2059 149 Lon Lake 1915 2055 140 Spokane Upper Falls 1922 2060 138 Nine Mile 1908 2060 152 Post Falls 1906 2060 154 Cabinet Gor e 1952 2072 120 Noxon Rapids 1959 2079 120 _____________________________________________________________________________________________ Avista Corporation December 31, 2021III- Attachment C J. Spanos, Avista Page 42 of 800 Rathdrum Turbine 1999 2034 35 Lancaster 2010 2040 30 Central Operations 2009 2029 20 The survivor curve estimates for the remaining accounts were based on judgment incorporating the statistical analyses and previous studies for this and other electric and gas utilities. Other Production Plant 2002 2038 36 1978,2002 2035 57,33 2002 2042 40 Kettle Falls Northeast Turbine Boulder Park Coyote Springs 2 2003 2043 40 _____________________________________________________________________________________________ Avista Corporation December 31, 2021III- Attachment C J. Spanos, Avista Page 43 of 800 PART IV. NET SALVAGE CONSIDERATIONS _____________________________________________________________________________________________ Avista Corporation December 31, 2021IV-1 Attachment C J. Spanos, Avista Page 44 of 800 PART IV. NET SALVAGE CONSIDERATIONS NET SALVAGE ANALYSIS The estimates of net salvage by account were based in part on historical data compiled through 2021. Cost of removal and gross salvage were expressed as percents of the original cost of plant retired, both on annual and three-year moving average bases. The most recent five-year average also was calculated for consideration. The net salvage estimates by account are expressed as a percent of the original cost of plant retired. Net Salvage Considerations The estimates of future net salvage are expressed as percentages of surviving plant in service, i.e., all future retirements. In cases in which removal costs are expected to exceed salvage receipts, a negative net salvage percentage is estimated. The net salvage estimates were based on judgment which incorporated analyses of historical cost of removal and gross salvage data, expectations with respect to future removal requirements and markets for retired equipment and materials. The analyses of historical cost of removal and gross salvage data are presented in the section titled “Net Salvage Statistics” for the plant accounts for which the net salvage estimate relied partially on those analyses. Statistical analyses of historical data for the period 1983 through 2021 contributed significantly toward the net salvage estimates for many plant accounts or subaccounts, representing 89 percent of the depreciable plant, listed below. _____________________________________________________________________________________________ Avista Corporation December 31, 2021IV-2 Attachment C J. Spanos, Avista Page 45 of 800 Account No. Account Description ELECTRIC PLANT Steam Production Plant 311.00 Structures and Improvements 312.00 Boiler Plant Equipment 314.00 Turbogenerators 315.00 Accessory Electric Equipment Hydro Production Plant 331.00 Structures and Improvements 332.00 Reservoirs, Dams and Waterways 333.00 Turbines and Generators 334.00 Accessory Electric Equipment 335.00 Miscellaneous Power Plant Equipment Other Production Plant 341.00 Structures and Improvements 344.00 Generators 345.00 Accessory Electric Equipment 346.00 Miscellaneous Power Plant Equipment Transmission Plant 352.00 Structures and Improvements 353.00 Station Equipment 355.00 Poles and Fixtures 356.00 Overhead Conductors and Devices Distribution Plant 361.00 Structures and Improvements 362.00 Station Equipment 364.00 Poles, Towers and Fixtures 365.00 Overhead Conductors and Devices 366.00 Underground Conduit 367.00 Underground Conductors and Devices 368.00 Line Transformers 369.10 Services – Overhead 369.20 Services – Underground – Spokane Network 369.30 Services – Underground – Other 370.10 Meters – Idaho 370.30 Meters – Washington Standard 370.40 Meters – Washington AMI 373.10 Street Lighting & Signal Systems – Mercury Vapor 373.20 Street Lighting & Signal Systems – Underground Conductor 373.30 Street Lighting & Signal Systems – Decorative and Metal Standards 373.40 Street Lighting & Signal Systems – High Pressure Sodium Vapor 373.50 Street Lighting & Signal Systems – LED _____________________________________________________________________________________________ Avista Corporation December 31, 2021IV-3 Attachment C J. Spanos, Avista Page 46 of 800 General Plant 390.10 Structures and Improvements – Company GAS PLANT Distribution Plant 375.00 Structures and Improvements 376.00 Mains 378.00 Measuring and Regulating Equipment – General 379.00 Measuring and Regulating Equipment – City Gate 380.00 Services 381.00 Meters 385.00 Industrial Measuring and Regulating Station Equipment COMMON PLANT 390.10 Structures and Improvements - Company Electric Plant Account 368.00, Line Transformers, is used to illustrate the manner in which the study was conducted for the groups in the preceding list. Net salvage data for the period 1983 through 2021 were analyzed for this account. The data include cost of removal, gross salvage and net salvage amounts and each of these amounts is expressed as a percent of the original cost of regular retirements. Three-year moving averages for the 1983-1985 through 2019-2021 periods were computed to smooth the annual amounts. Cost of removal fluctuated during the 39-year period. The primary cause of cost of removal was the effort needed to take out the transformers. Cost of removal for the most recent five years averaged 47 percent, however, 2015 and 2016 were considerably higher. Gross salvage has varied throughout the period, however it has been low in recent years, except for 2021. The most recent five-year average of 87 percent gross salvage is not a reflection of future expectations for line transformers as the 2021 amount is not indicative of future scrap value. The net salvage percent based on the overall period _____________________________________________________________________________________________ Avista Corporation December 31, 2021IV-4 Attachment C J. Spanos, Avista Page 47 of 800 1983 through 2021 is 3 percent negative net salvage and based on the most recent five- year period when excluding the 2021 amount is negative 43 percent. The range of estimates made by other electric companies for line transformers is positive 5 to negative 15 percent. The net salvage estimate for line transformers is negative 10 percent, is within the range of other estimates and reflects expectations of the future for negative net salvage. For Electric Account 364.00, Poles, Towers and Fixtures, cost of removal fluctuated throughout the period but has trended to a high level since 2002. The primary cause of the high level of cost of removal was the required effort needed to take out the poles and towers. Cost of removal for the most recent five years averaged 48 percent. Gross salvage was generally high until 2011, then has been minimal for the last ten years. The most recent five-year average of 1 percent gross salvage reflects recent trends and the reduced market for poles. The net salvage percent based on the overall period 1983 through 2021 is 57 percent negative net salvage and based on the most recent five-year period is 47 percent. The range of estimates made by other electric companies for Poles, Towers and Fixtures is negative 20 to negative 75 percent. The net salvage estimate for poles is negative 60 percent, is within the range of other estimates but does not reflect the trend toward lower negative net salvage due to the lag in recording some cost of removal. The overall net salvage percent for steam, hydro and other production facilities include costs for final retirement. The calculation of the weighted net salvage percent includes costs by unit for final retirement as well as interim retirements prior to final retirement. The overall net salvage for each production facility combines the interim net _____________________________________________________________________________________________ Avista Corporation December 31, 2021IV-5 Attachment C J. Spanos, Avista Page 48 of 800 salvage amount with the final dismantlement amount factored to the total plant cost. The calculation for each facility is set forth on pages VIII-2 through VIII-6 of this study. The net salvage estimates for the remaining plant accounts were estimated using the above-described process of historical indications, judgment and reviewing the typical range of estimates used by other electric and gas companies. The results of the net salvage for each plant account are presented in account sequence in the section titled “Net Salvage Statistics”, beginning on page VIII-8. Generally, the net salvage estimates for the general plant accounts were zero percent, consistent with amortization accounting. _____________________________________________________________________________________________ Avista Corporation December 31, 2021IV-6 Attachment C J. Spanos, Avista Page 49 of 800 PART V. CALCULATION OF ANNUAL AND ACCRUED DEPRECIATION _____________________________________________________________________________________________ Avista Corporation December 31, 2021V-1 Attachment C J. Spanos, Avista Page 50 of 800 PART V. CALCULATION OF ANNUAL AND ACCRUED DEPRECIATION GROUP DEPRECIATION PROCEDURES A group procedure for depreciation is appropriate when considering more than a single item of property. Normally the items within a group do not have identical service lives, but have lives that are dispersed over a range of time. There are two primary group procedures, namely, average service life and equal life group. In the average service life procedure, which was used in this study, the rate of annual depreciation is based on the average life or average remaining life of the group, and this rate is applied to the surviving balances of the group's cost. A characteristic of this procedure is that the cost of plant retired prior to average life is not fully recouped at the time of retirement, whereas the cost of plant retired subsequent to average life is more than fully recouped. Over the entire life cycle, the portion of cost not recouped prior to average life is balanced by the cost recouped subsequent to average life. Single Unit of Property The calculation of straight line depreciation for a single unit of property is straightforward. For example, if a $1,000 unit of property attains an age of four years and has a life expectancy of six years, the annual accrual over the total life is: $1,000 4 + 6 $100 per year. The accrued depreciation is: $1,000 1 - 6 10 $400.§ ©¨· ¹¸ _____________________________________________________________________________________________ Avista Corporation December 31, 2021V-2 Attachment C J. Spanos, Avista Page 51 of 800 Remaining Life Annual Accruals For the purpose of calculating remaining life accruals as of December 31, 2021, the depreciation reserve for each plant account is allocated among vintages in proportion to the calculated accrued depreciation for the account. Explanations of remaining life accruals and calculated accrued depreciation follow. The detailed calculations as of December 31, 2021, are set forth in the Results of Study section of the report. Average Service Life Procedure In the average service life procedure, the remaining life annual accrual for each vintage is determined by dividing future book accruals (original cost less book reserve) by the average remaining life of the vintage. The average remaining life is a directly weighted average derived from the estimated future survivor curve in accordance with the average service life procedure. The calculated accrued depreciation for each depreciable property group represents that portion of the depreciable cost of the group which would not be allocated to expense through future depreciation accruals if current forecasts of life characteristics are used as the basis for such accruals. The accrued depreciation calculation consists of applying an appropriate ratio to the surviving original cost of each vintage of each account based upon the attained age and service life. The straight line accrued depreciation ratios are calculated as follows for the average service life procedure: Ratio = 1 - Average Remaining Life Average Service Life . _____________________________________________________________________________________________ Avista Corporation December 31, 2021V-3 Attachment C J. Spanos, Avista Page 52 of 800 CALCULATION OF ANNUAL AND ACCRUED AMORTIZATION Amortization is the gradual extinguishment of an amount in an account by distributing such amount over a fixed period, over the life of the asset or liability to which it applies, or over the period during which it is anticipated the benefit will be realized. Normally, the distribution of the amount is in equal amounts to each year of the amortization period. The calculation of annual and accrued amortization requires the selection of an amortization period. The amortization periods used in this report were based on judgment which incorporated a consideration of the period during which the assets will render most of their service, the amortization period and service lives used by other utilities, and the service life estimates previously used for the asset under depreciation accounting. Amortization accounting is proposed for a number of accounts that represent numerous units of property, but a very small portion of depreciable utility plant in service. The accounts and their amortization periods are as follows: AMORTIZATION PERIOD, ACCT TITLE YEARS Electric Plant 391.00 Office Furniture and Equipment 15 391.10, Computer Hardware 5 391.12, Computer Hardware – AMI 5 393.00, Stores Equipment 25 394.00, Tools, Shop and Gara e Equipment 20 395.00, Laborator Equipment 15 395.12, Laborator Equipment – AMI 15 397.00, Communication Equipment 15 397.50, Sub Inte ration 15 397.60, Distribution 15 398.00, Miscellaneous Equipment 10 _____________________________________________________________________________________________ Avista Corporation December 31, 2021V- Attachment C J. Spanos, Avista Page 53 of 800 AMORTIZATION PERIOD, ACCT TITLE YEARS Gas Plant 391.10, Computer Hardware 5 393.00, Stores Equipment 25 394.00, Tools, Shop and Gara e Equipment 20 395.00, Laborator Equipment 15 395.12, Laborator Equipment – AMI 15 397.00, Communication Equipment 15 397.12, Communication Equipment – AMI 15 398.00, Miscellaneous Equipment 10 Common Plant 391.00, Office Furniture and Equipment 15 391.10, Computer Hardware 5 391.12, Computer Hardware – AMI 5 391.13, Computer Hardware – MDM 5 393.00, Stores Equipment 25 394.00, Tools, Shop and Gara e Equipment 20 395.00, Laborator Equipment 15 397.00, Communication Equipment 15 397.12, Communication Equipment – AMI 15 397.20, Communication Equipment – Portable 10 398.00, Miscellaneous Equipment 10 For the purpose of calculating annual amortization amounts as of December 31, 2021, the book depreciation reserve for each plant account or subaccount is assigned or allocated to vintages. The book reserve assigned to vintages with an age greater than the amortization period is equal to the vintage’s original cost. The remaining book reserve is allocated among vintages with an age less than the amortization period in proportion to the calculated accrued amortization. The calculated accrued amortization is equal to the original cost multiplied by the ratio of the vintage’s age to its amortization period. The annual amortization amount is determined by dividing the future amortizations (original cost less allocated book reserve) by the remaining period of amortization for the vintage. _____________________________________________________________________________________________ Avista Corporation December 31, 2021V- Attachment C J. Spanos, Avista Page 54 of 800 PART VI. RESULTS OF STUDY _____________________________________________________________________________________________ Avista Corporation December 31, 2021VI-1 Attachment C J. Spanos, Avista Page 55 of 800 PART VI. RESULTS OF STUDY QUALIFICATION OF RESULTS The calculated annual and accrued depreciation are the principal results of the study. Continued surveillance and periodic revisions are normally required to maintain continued use of appropriate annual depreciation accrual rates. An assumption that accrual rates can remain unchanged over a long period of time implies a disregard for the inherent variability in service lives and net salvage and for the change of the composition of property in service. The annual accrual rates were calculated in accordance with the straight line remaining life method of depreciation, using the average service life procedure based on estimates which reflect considerations of current historical evidence and expected future conditions. The annual depreciation accrual rates are applicable specifically to the electric, gas and common plant in service as of December 31, 2021. For most plant accounts, the application of such rates to future balances that reflect additions subsequent to December 31, 2021, is reasonable for a period of up to five years. DESCRIPTION OF DETAILED TABULATIONS Table 1 is a summary of the results of the study as applied to the original cost of electric, gas and common plant respectively, as of December 31, 2021. The summary schedules are presented on pages VI-4 through VI-15 of this report. The service life estimates were based on judgment that incorporated statistical analysis of retirement data, discussions with management and consideration of estimates made for other electric and gas utilities. The results of the statistical analysis of service _____________________________________________________________________________________________ Avista Corporation December 31, 2021VI- Attachment C J. Spanos, Avista Page 56 of 800 life are presented in the section beginning on page VII-2, within the supporting documents of this report. For each depreciable group analyzed by the retirement rate method, a chart depicting the original and estimated survivor curves is followed by a tabular presentation of the original life table(s) plotted on the chart. The survivor curves estimated for the depreciable groups are shown as dark smooth curves on the charts. Each smooth survivor curve is denoted by a numeral followed by the curve type designation. The numeral used is the average life derived from the entire curve from 100 percent to zero percent surviving. The titles of the chart indicate the group, the symbol used to plot the points of the original life table, and the experience and placement bands of the life tables which where plotted. The experience band indicates the range of years for which retirements were used to develop the stub survivor curve. The placements indicate, for the related experience band, the range of years of installations which appear in the experience. The analyses of net salvage data are presented in the section titled, “Net Salvage Statistics”. The tabulations present annual cost of removal and gross salvage data, three- year moving averages and the most recent five-year average. Data are shown in dollars and as percentages of original costs retired. The tables of the calculated annual depreciation applicable to depreciable assets as of December 31, 2021 are presented in account sequence starting on page IX-3 of the supporting documents. The tables indicate the estimated survivor curve and net salvage percent for the account and set forth, for each installation year, the original cost, the calculated accrued depreciation, the allocated book reserve, future accruals, the remaining life, and the calculated annual accrual amount. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VI-3 Attachment C J. Spanos, Avista Page 57 of 800 AV I S T A C O R P O R A T I O N TA B L E 1 . S U M M A R Y O F E S T I M A T E D S U R V I V O R C U R V E , N E T S A L V A G E P E R C E N T , O R I G I N A L C O S T , B O O K D E P R E C I A T I O N R E S E R V E A N D CA L C U L A T E D A N N U A L D E P R E C I A T I O N A C C R U A L S R E L A T E D T O E L E C T R I C , G A S A N D C O M M O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 PR O B A B L E NE T OR I G I N A L C O S T BO O K FU T U R E CA L C U L A T E D CO M P O S I T E RE T I R E M E N T SU R V I V I O R SA L V A G E AS O F DE P R E C I A T I O N BO O K AN N U A L A C C R U A L RE M A I N I N G DE P R E C I A B L E G R O U P DA T E CU R V E PE R C E N T DE C E M B E R 3 1 , 2 0 2 1 RE S E R V E AC C R U A L S AM O U N T RA T E LIF E (1 ) (2 ) (3 ) (4 ) (5 ) (6 ) (7 ) (8 ) (9 ) = ( 8 ) / ( 5 ) (1 0 ) = ( 7 ) / ( 8 ) EL E C T R I C P L A N T ST E A M P R O D U C T I O N P L A N T 31 0 . 3 0 RE M O V I N G O T H E R P R O P E R T Y K E T T L E F A L L S 12 - 2 0 3 8 SQ U A R E * 0 13 8 , 1 7 4 . 5 0 12 5 , 7 5 0 12 , 4 2 4 73 1 0.5 3 17 . 0 31 0 . 4 0 EA S E M E N T S , P E R M I T S K E T T L E F A L L S 12 - 2 0 3 8 SQ U A R E * 0 28 9 , 1 1 1 . 1 5 13 , 8 9 1 27 5 , 2 2 0 16 , 1 9 0 5.6 0 17 . 0 31 1 . 0 0 ST R U C T U R E S A N D I M P R O V E M E N T S K E T T L E F A L L S 12 - 2 0 3 8 75 - S 1 . 5 * (5 ) 25 , 2 8 8 , 2 7 2 . 1 9 20 , 8 4 8 , 8 6 6 5,7 0 3 , 8 2 0 34 8 , 4 7 0 1.3 8 16 . 4 C O L S T R I P 3 A N D C O M M O N - I D A H O 12 - 2 0 2 7 75 - S 1 . 5 * (3 ) 20 , 1 5 2 , 7 3 6 . 0 8 17 , 0 3 3 , 0 8 1 3,7 2 4 , 2 3 7 62 8 , 5 5 9 3.1 2 5.9 C O L S T R I P 3 A N D C O M M O N - W A S H I N G T O N 12 - 2 0 2 5 75 - S 1 . 5 * (3 ) 38 , 0 1 2 , 9 4 4 . 0 7 33 , 3 9 9 , 9 3 4 5,7 5 3 , 3 9 8 1,4 4 9 , 5 9 6 3.8 1 4.0 C O L S T R I P 4 - I D A H O 12 - 2 0 2 7 75 - S 1 . 5 * (4 ) 18 , 7 7 6 , 4 1 5 . 3 0 16 , 4 7 0 , 1 1 9 3,0 5 7 , 3 5 3 51 6 , 2 0 3 2.7 5 5.9 C O L S T R I P 4 - W A S H I N G T O N 12 - 2 0 2 5 75 - S 1 . 5 * (4 ) 35 , 4 1 6 , 9 7 3 . 9 4 31 , 0 1 4 , 1 1 5 5,8 1 9 , 5 3 8 1,4 6 7 , 4 4 0 4.1 4 4.0 TO T A L A C C O U N T 3 1 1 . 0 0 13 7 , 6 4 7 , 3 4 1 . 5 8 11 8 , 7 6 6 , 1 1 6 24 , 0 5 8 , 3 4 6 4,4 1 0 , 2 6 8 3.2 0 31 1 . 1 0 ST R U C T U R E S A N D I M P R O V E M E N T S - L A N D F I L L K E T T L E F A L L S 12 - 2 0 3 8 55 - S 3 * 0 3,6 4 8 , 8 5 1 . 1 6 3, 0 3 8 , 7 0 4 61 0 , 1 4 7 38 , 4 0 6 1.0 5 15 . 9 31 2 . 0 0 BO I L E R P L A N T E Q U I P M E N T K E T T L E F A L L S 12 - 2 0 3 8 55 - R 1 * (5 ) 46 , 8 0 1 , 6 8 5 . 6 0 30 , 0 1 4 , 1 1 4 19 , 1 2 7 , 6 5 6 1,2 2 8 , 3 7 1 2.6 2 15 . 6 C O L S T R I P 3 A N D C O M M O N - I D A H O 12 - 2 0 2 7 55 - R 1 * (3 ) 30 , 4 2 4 , 8 0 1 . 1 3 24 , 6 5 6 , 4 2 1 6,6 8 1 , 12 4 1,14 5 , 7 5 7 3.7 7 5.8 C O L S T R I P 3 A N D C O M M O N - W A S H I N G T O N 12 - 2 0 2 5 55 - R 1 * (3 ) 55 , 9 6 0 , 8 6 2 . 7 8 48 , 2 7 7 , 4 9 1 9,3 6 2 , 1 9 8 2,3 8 2 , 6 0 6 4.26 3.9 C O L S T R I P 4 - I D A H O 12 - 2 0 2 7 55 - R 1 * (4 ) 21 , 5 6 5 , 5 8 5 . 2 5 15 , 9 3 0 , 2 7 0 6,4 9 7 , 9 3 8 1,1 1 0 , 1 7 4 5.1 5 5.9 C O L S T R I P 4 - W A S H I N G T O N 12 - 2 0 2 5 55 - R 1 * (4 ) 39 , 3 9 1 , 8 9 1 . 5 3 29 , 7 2 5 , 2 0 2 11 , 2 4 2 , 3 6 5 2,8 5 7 , 3 1 9 7.2 5 3.9 TO T A L A C C O U N T 3 1 2 . 0 0 19 4 , 1 4 4 , 8 2 6 . 2 9 14 8 , 6 0 3 , 4 9 8 52 , 9 1 1 , 2 8 1 8,7 2 4 , 2 2 7 4.4 9 31 3 . 0 0 EN G I N E S A N D E N G I N E - D R I V E N G E N E R A T O R S C O L S T R I P 3 A N D C O M M O N - I D A H O 12 - 2 0 2 7 50 - R 2 . 5 * (3 ) 17 5 , 4 6 0 . 6 5 12 , 3 9 4 16 8 , 3 3 1 28 , 1 5 0 16 . 0 4 6.0 C O L S T R I P 3 A N D C O M M O N - W A S H I N G T O N 12 - 2 0 2 5 50 - R 2 . 5 * (3 ) 33 3 , 1 2 2 . 6 5 37 , 1 1 9 30 5 , 9 9 7 76 , 6 9 2 23 . 0 2 4.0 C O L S T R I P 4 - I D A H O 12 - 2 0 2 7 50 - R 2 . 5 * (4 ) 11 , 3 9 4 . 2 9 7,8 2 4 4,0 2 6 67 3 5.9 1 6.0 C O L S T R I P 4 - W A S H I N G T O N 12 - 2 0 2 5 50 - R 2 . 5 * (4 ) 21 , 0 8 2 . 7 2 26 , 4 7 9 (4 , 5 5 3 ) 0 - - TO T A L A C C O U N T 3 1 3 . 0 0 54 1 , 0 6 0 . 3 1 83 , 8 1 6 47 3 , 8 0 1 10 5 , 5 1 5 19 . 5 0 31 4 . 0 0 TU R B O G E N E R A T O R S K E T T L E F A L L S 12 - 2 0 3 8 37 - R 0 . 5 * (5 ) 18 , 6 3 2 , 0 8 8 . 9 0 12 , 1 8 4 , 2 9 8 7,3 7 9 , 3 9 6 51 9 , 7 8 5 2.7 9 14 . 2 C O L S T R I P 3 A N D C O M M O N - I D A H O 12 - 2 0 2 7 37 - R 0 . 5 * (3 ) 8,3 3 0 , 8 0 8 . 1 8 6, 5 5 3 , 8 4 9 2,0 2 6 , 8 8 3 35 7 , 0 2 1 4.2 9 5. 7 C O L S T R I P 3 A N D C O M M O N - W A S H I N G T O N 12 - 2 0 2 5 37 - R 0. 5 * (3 ) 15 , 7 1 4 , 3 5 3 . 7 4 11 , 7 0 3 , 6 3 0 4,4 8 2 , 1 5 4 1,1 6 6 , 3 7 5 7.4 2 3.8 C O L S T R I P 4 - I D A H O 12 - 2 0 2 7 37 - R 0 . 5 * (4 ) 6,0 1 8 , 1 0 0 . 9 1 3, 6 9 3 , 4 4 6 2,5 6 5 , 3 7 9 45 1 , 0 0 0 7.4 9 5.7 C O L S T R I P 4 - W A S H I N G T O N 12 - 2 0 2 5 37 - R 0 . 5 * (4 ) 11 , 3 6 1 , 0 5 1 . 53 6, 7 8 1 , 4 8 4 5,0 3 4 , 0 1 0 1,3 0 4 , 7 5 6 11 . 4 8 3.9 TO T A L A C C O U N T 3 1 4 . 0 0 60 , 0 5 6 , 4 0 3 . 2 6 40 , 9 1 6 , 7 0 7 21 , 4 8 7 , 8 2 2 3,7 9 8 , 9 3 7 6.3 3 31 5 . 0 0 AC C E S S O R Y E L E C T R I C E Q U I P M E N T K E T T L E F A L L S 12 - 2 0 3 8 50 - S 1 * (5 ) 12 , 5 9 6 , 0 4 9 . 0 1 7, 1 9 1 , 5 0 0 6,0 3 4 , 3 5 2 39 3 , 9 8 7 3.1 3 15 . 3 C O L S T R I P 3 A N D C O M M O N - I D A H O 12 - 2 0 2 7 50 - S 1 * (3 ) 3,8 7 5 , 9 4 0 . 3 1 2, 9 9 4 , 7 6 2 99 7 , 4 5 7 17 1 , 4 7 7 4.4 2 5.8 C O L S T R I P 3 A N D C O M M O N - W A S H I N G T O N 12 - 2 0 2 5 50 - S 1 * (3 ) 7,3 8 3 , 2 4 4 . 1 2 5, 8 2 2 , 7 1 1 1,7 8 2 , 0 3 0 45 3 , 7 4 0 6.1 5 3.9 C O L S T R I P 4 - I D A H O 12 - 2 0 2 7 50 - S 1 * (4 ) 2,6 7 7 , 7 5 6 . 9 2 2, 0 2 7 , 6 9 2 75 7 , 1 7 6 13 0 , 6 5 0 4.8 8 5.8 C O L S T R I P 4 - W A S H I N G T O N 12 - 2 0 2 5 50 - S 1 * (4 ) 4,9 8 6 , 6 4 1 . 5 5 3, 8 7 2 , 9 2 5 1,3 1 3 , 1 8 2 33 5 , 9 9 9 6.7 4 3.9 TO T A L A C C O U N T 3 1 5 . 0 0 31 , 5 1 9 , 6 3 1 . 9 1 21 , 9 0 9 , 5 9 0 10 , 8 8 4 , 1 9 7 1,4 8 5 , 8 5 3 4.7 1 31 6 . 0 0 MIS C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T K E T T L E F A L L S 12 - 2 0 3 8 60 - R 2 * (5 ) 2,4 7 6 , 9 5 9 . 1 9 2, 0 1 6 , 9 7 7 58 3 , 8 3 0 37 , 5 9 3 1.5 2 15 . 5 C O L S T R I P 3 A N D C O M M O N - I D A H O 12 - 2 0 2 7 60 - R 2 * (3 ) 3,4 9 2 , 5 9 0 . 3 8 3, 0 4 6 , 99 9 55 0 , 36 9 93 , 3 0 5 2.6 7 5.9 C O L S T R I P 3 A N D C O M M O N - W A S H I N G T O N 12 - 2 0 2 5 60 - R 2 * (3 ) 6,5 8 9 , 2 3 8 . 9 2 5, 6 2 2 , 3 0 5 1,1 6 4 , 6 1 1 29 4 , 7 4 7 4.4 7 4.0 C O L S T R I P 4 - I D A H O 12 - 2 0 2 7 60 - R 2 * (4 ) 1,5 7 4 , 2 8 4 . 7 1 1, 3 7 0 , 8 7 5 26 6 , 3 8 1 45 , 3 9 0 2.8 8 5.9 C O L S T R I P 4 - W A S H I N G T O N 12 - 2 0 2 5 60 - R 2 * (4 ) 2,9 6 8 , 6 9 8 . 7 6 2, 5 1 8 , 3 1 4 56 9 , 1 3 3 14 4 , 4 5 8 4.8 7 3.9 TO T A L A C C O U N T 3 1 6 . 0 0 17 , 1 0 1 , 7 7 1 . 9 6 14 , 5 7 5 , 4 7 1 3,13 4 , 3 2 4 61 5 , 4 9 3 3.6 0 TO T A L S T E A M P R O D U C T I O N P L A N T 44 5 , 0 8 7 , 1 7 2 . 1 2 34 8 , 0 3 3 , 5 4 3 11 3 , 8 4 7 , 5 6 2 19 , 1 9 5 , 6 2 0 4.3 1 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VI-4 Attachment C J. Spanos, Avista Page 58 of 800 AV I S T A C O R P O R A T I O N TA B L E 1 . S U M M A R Y O F E S T I M A T E D S U R V I V O R C U R V E , N E T S A L V A G E P E R C E N T , O R I G I N A L C O S T , B O O K D E P R E C I A T I O N R E S E R V E A N D CA L C U L A T E D A N N U A L D E P R E C I A T I O N A C C R U A L S R E L A T E D T O E L E C T R I C , G A S A N D C O M M O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 PR O B A B L E NE T OR I G I N A L C O S T BO O K FU T U R E CA L C U L A T E D CO M P O S I T E RE T I R E M E N T SU R V I V I O R SA L V A G E AS O F DE P R E C I A T I O N BO O K AN N U A L A C C R U A L RE M A I N I N G DE P R E C I A B L E G R O U P DA T E CU R V E PE R C E N T DE C E M B E R 3 1 , 2 0 2 1 RE S E R V E AC C R U A L S AM O U N T RA T E LIF E (1 ) (2 ) (3 ) (4 ) (5 ) (6 ) (7 ) (8 ) (9 ) = ( 8 ) / ( 5 ) (1 0 ) = ( 7 ) / ( 8 ) HY D R O P R O D U C T I O N P L A N T 33 0 . 1 0 AS S E T A G R E E M E N T - S E T T L E M E N T L I T T L E F A L L S 12 - 2 0 5 9 50 - S Q 0 4,2 0 0 , 0 0 0 . 0 0 2, 1 0 7 , 1 0 0 2,0 9 2 , 9 0 0 83 , 3 9 4 1.9 9 25 . 1 33 0 . 3 0 RE M O V I N G P R O P E R T Y O F O T H E R S L I T T L E F A L L S 12 - 2 0 5 9 10 0 - R 4 * 0 13 , 6 3 3 . 6 0 10 , 6 7 6 2,9 5 8 17 0 1.2 5 17 . 4 L O N G L A K E 12 - 2 0 5 5 10 0 - R 4 * 0 17 1 , 0 7 9 . 5 5 10 9 , 4 3 4 61 , 6 4 5 2, 2 9 6 1.3 4 26 . 8 S P O K A N E U P P E R F A L L S 12 - 2 0 6 0 10 0 - R 4 * 0 63 , 5 6 3 . 7 6 54 , 9 2 0 8,6 4 4 54 1 0.8 5 16 . 0 N I N E M I L E 12 - 2 0 6 0 10 0 - R 4 * 0 9,9 3 6 . 7 5 7,7 4 7 2,1 9 0 58 0.5 8 37 . 8 P O S T F A L L S 12 - 2 0 6 0 10 0 - R 4 * 0 23 , 1 6 6 . 8 9 16 , 8 5 1 6,3 1 6 32 0 1.3 8 19 . 7 C A B I N E T G O R G E 12 - 2 0 7 2 10 0 - R 4 * 0 6,7 8 3 , 2 3 6 . 8 9 2, 5 2 4 , 1 5 9 4,2 5 9 , 0 7 7 12 5 , 2 0 2 1.8 5 34 . 0 N O X O N R A P I D S 12 - 2 0 7 9 10 0 - R 4 * 0 29 , 4 1 3 , 6 2 1 . 6 4 9, 3 3 2 , 6 4 7 20 , 0 8 0 , 9 7 5 51 2 , 6 3 7 1.7 4 39 . 2 TO T A L A C C O U N T 3 3 0 . 3 0 36 , 4 7 8 , 2 3 9 . 0 8 12 , 0 5 6 , 4 3 4 24 , 4 2 1 , 8 0 5 64 1 , 2 2 4 1.7 6 33 0 . 3 1 TW I N C R E E K C H A N N E L R E S T O R A T I O N C A B I N E T G O R G E 12 - 2 0 7 2 10 0 - R 4 * 0 24 2 , 0 3 3 . 0 2 60 , 6 0 9 18 1 , 4 2 4 3, 6 2 3 1.5 0 50 . 1 33 0 . 4 0 LA N D E A S E M E N T S L I T T L E F A L L S 12 - 2 0 5 9 90 - R 4 * 0 3,6 2 6 . 6 7 3,6 2 7 0 0 - - L O N G L A K E 12 - 2 0 5 5 90 - R 4 * 0 24 6 , 5 6 2 . 2 5 23 9 , 8 9 6 6,6 6 6 29 8 0.1 2 22 . 4 N I NE M I L E 12 - 2 0 6 0 90 - R 4 * 0 97 9 . 5 0 98 0 0 0 - - P O S T F A L L S 12 - 2 0 6 0 90 - R 4 * 0 2,7 0 8 , 4 3 7 . 1 1 1, 6 8 4 , 6 4 7 1,0 2 3 , 7 9 1 28 , 2 1 0 1.0 4 36 . 3 C A B I N E T G O R G E 12 - 2 0 7 2 90 - R 4 * 0 36 5 , 9 2 4 . 3 5 16 5 , 0 7 5 20 0 , 8 5 0 7, 5 6 3 2.0 7 26 . 6 N O X O N R A P I D S 12 - 2 0 7 9 90 - R 4 * 0 80 , 8 6 9 . 9 1 13 , 1 0 5 67 , 7 6 5 1, 2 5 1 1.5 5 54 . 2 TO T A L A C C O U N T 3 3 0 . 4 0 3,4 0 6 , 3 9 9 . 7 9 2, 1 0 7 , 3 2 9 1,2 9 9 , 0 7 2 37 , 3 2 2 1.1 0 33 0 . 4 1 LA N D E A S E M E N T S - C O N S E R V A T I O N - H A B I T A T C A B I N E T G O R G E 12 - 2 0 7 2 90 - R 4 * 0 1,9 9 2 , 2 0 8 . 0 4 21 4 , 5 1 0 1,7 7 7 , 6 9 8 35 , 3 4 4 1.7 7 50 . 3 N O X O N R A P I D S 12 - 2 0 7 9 90 - R 4 * 0 98 2 , 2 3 4 . 9 7 21 2 , 5 9 2 76 9 , 6 4 3 13 , 8 6 5 1.4 1 55 . 5 TO T A L A C C O U N T 3 3 0 . 4 1 2,9 7 4 , 4 4 3 . 0 1 42 7 , 1 0 2 2,5 4 7 , 3 4 1 49 , 2 0 9 1.6 5 33 1 . 0 0 ST R U C T U R E S A N D I M P R O V E M E N T S M O N R O E S T R E E T 12 - 2 0 7 2 11 0 - R 1 . 5 * (7 ) 8,1 9 8 , 9 8 6 . 3 5 1, 8 3 1 , 7 4 7 6,9 4 1 , 1 6 8 14 9 , 6 3 8 1.8 3 46 . 4 L I T T L E F A L L S 12 - 2 0 5 9 11 0 - R 1 . 5 * (5 ) 5,4 7 1 , 9 2 9 . 5 4 1, 1 4 0 , 9 8 0 4,6 0 4 , 5 4 6 12 6 , 9 4 0 2.3 2 36 . 3 L O N G L A K E 12 - 2 0 5 5 11 0 - R 1 . 5 * (6 ) 7,68 6 , 25 2 . 0 1 1, 4 6 6 , 5 8 8 6,6 8 0 , 8 3 9 20 6 , 7 0 0 2.6 9 32 . 3 S P O K A N E U P P E R F A L L S 12 - 2 0 6 0 11 0 - R 1 . 5 * (6 ) 1,1 1 4 , 5 7 9 . 6 1 53 5 , 1 1 5 64 6 , 3 3 9 17 , 5 0 2 1.5 7 36 . 9 N I N E M I L E 12 - 2 0 6 0 11 0 - R 1 . 5 * (4 ) 20 , 0 4 9 , 0 5 9 . 5 2 2, 1 8 9 , 9 1 1 18 , 6 6 1 , 1 1 1 50 2 , 4 6 4 2.5 1 37 . 1 P O S T F A L L S 12 - 2 0 6 0 11 0 - R 1 . 5 * (4 ) 6,7 5 1 , 6 6 6 . 1 6 89 9 , 7 5 4 6,1 2 1 , 9 7 8 16 4 , 1 5 9 2.4 3 37 . 3 C A B I N E T G O R G E 12 - 2 0 7 2 11 0 - R 1 . 5 * (1 3 ) 23 , 4 3 4 , 8 6 8 . 7 0 5, 7 1 6 , 4 1 5 20 , 7 6 4 , 9 8 6 44 6 , 4 8 4 1.9 1 46 . 5 N O X O N R A P I D S 12 - 2 0 7 9 11 0 - R 1 . 5 * (2 1 ) 21 , 4 8 7 , 7 5 9 . 8 5 5, 8 9 9 , 7 3 4 20 , 1 0 0 , 4 5 5 39 1 , 3 4 9 1.8 2 51 . 4 TO T A L A C C O U N T 3 3 1 . 0 0 94 , 1 9 5 , 1 0 1 . 7 4 19 , 6 8 0 , 2 4 5 84 , 5 2 1 , 4 2 2 2,0 0 5 , 2 3 6 2.1 3 33 1 . 1 0 ST R U C T U R E S A N D I M P R O V E M E N T S - F I S H A N D W I L D L I F E C O N S E R V A T I O N L O N G L A K E 12 - 2 0 5 5 55 - S 2 . 5 * (6 ) 66 , 3 7 8 . 3 3 64 , 9 1 4 5,4 4 7 20 5 0.3 1 26 . 6 P O S T F A L L S 12 - 2 0 6 0 55 - S 2 . 5 * (4 ) 6,1 8 1 . 0 9 2,6 7 3 3,7 5 6 10 1 1.6 3 37 . 2 C A B I N E T G O R G E 12 - 2 0 7 2 55 - S 2 . 5 * (1 3 ) 31 , 6 5 0 . 0 7 11 , 6 2 0 24 , 1 4 4 61 6 1.9 5 39 . 2 N O X O N R A P I D S 12 - 2 0 7 9 55 - S 2 . 5 * (2 1 ) 1,0 9 0 , 1 2 1 . 0 7 11 5 , 4 8 6 1,2 0 3 , 5 6 1 26 , 8 3 6 2.4 6 44 . 8 TO T A L A C C O U N T 3 3 1 . 1 0 1,1 9 4 , 3 3 0 . 5 6 19 4 , 6 9 3 1,2 3 6 , 9 0 8 27 , 7 5 8 2.3 2 33 1 . 2 0 ST R U C T U R E S A N D I M P R O V E M E N T S - R E C R E A T I O N M O N R O E S T R E E T 12 - 2 0 7 2 50 - R 2 . 5 * (7 ) 4,0 3 7 , 0 2 4 . 9 4 66 0 , 3 9 5 3,6 5 9 , 2 2 2 96 , 2 6 5 2.3 8 38 . 0 L O N G L A K E 12 - 2 0 5 5 50 - R 2 . 5 * (6 ) 1,7 2 0 , 6 8 1 . 9 1 39 8 , 5 9 8 1,4 2 5 , 3 2 5 46 , 2 1 7 2.6 9 30 . 8 S P O K A N E U P P E R F A L L S 12 - 2 0 6 0 50 - R 2 . 5 * (6 ) 5,9 7 9 . 7 0 6,4 0 1 (6 2 ) 0 - - N I N E M I L E 12 - 2 0 6 0 50 - R 2 . 5 * (4 ) 37 0 , 7 5 1 . 6 6 84 , 11 6 30 1 , 4 6 6 8, 6 6 4 2.3 4 34 . 8 P O S T F A L L S 12 - 2 0 6 0 50 - R 2 . 5 * (4 ) 90 1 , 1 7 8 . 7 4 14 2 , 1 9 4 79 5 , 0 3 2 23 , 3 1 6 2. 5 9 34 . 1 C A B I N E T G O R G E 12 - 2 0 7 2 50 - R 2 . 5 * (1 3 ) 2,3 5 4 , 0 4 2 . 2 6 49 3 , 5 5 9 2, 1 6 6 , 5 0 9 53 , 8 4 0 2. 2 9 40 . 2 N O X O N R A P I D S 12 - 2 0 7 9 50 - R 2 . 5 * (2 1 ) 2,3 3 2 , 3 0 9 . 5 1 50 2 , 1 9 9 2, 3 1 9 , 8 9 5 57 , 3 4 3 2. 4 6 40 . 5 TO T A L A C C O U N T 3 3 1 . 2 0 11 , 7 2 1 , 9 6 8 . 7 2 2, 2 8 7 , 4 6 2 10 , 6 6 7 , 3 8 7 28 5 , 6 4 5 2. 4 4 33 1 . 2 6 ST R U C T U R E S A N D I M P R O V E M E N T S - R E C R E A T I O N I N F O R M A T I O N A N D E D U C A T I O N C A B I N E T G O R G E 12 - 2 0 7 2 50 - R 3 * (1 3 ) 37 , 9 1 0 . 9 1 18 , 0 7 7 24 , 7 6 3 64 2 1. 6 9 38 . 6 N O X O N R A P I D S 12 - 2 0 7 9 50 - R 3 * (2 1 ) 13 , 6 0 5 . 5 6 6,0 9 9 10 , 3 6 4 28 9 2. 1 2 35 . 9 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VI-5 Attachment C J. Spanos, Avista Page 59 of 800 AV I S T A C O R P O R A T I O N TA B L E 1 . S U M M A R Y O F E S T I M A T E D S U R V I V O R C U R V E , N E T S A L V A G E P E R C E N T , O R I G I N A L C O S T , B O O K D E P R E C I A T I O N R E S E R V E A N D CA L C U L A T E D A N N U A L D E P R E C I A T I O N A C C R U A L S R E L A T E D T O E L E C T R I C , G A S A N D C O M M O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 PR O B A B L E NE T OR I G I N A L C O S T BO O K FU T U R E CA L C U L A T E D CO M P O S I T E RE T I R E M E N T SU R V I V I O R SA L V A G E AS O F DE P R E C I A T I O N BO O K AN N U A L A C C R U A L RE M A I N I N G DE P R E C I A B L E G R O U P DA T E CU R V E PE R C E N T DE C E M B E R 3 1 , 2 0 2 1 RE S E R V E AC C R U A L S AM O U N T RA T E LIF E (1 ) (2 ) (3 ) (4 ) (5 ) (6 ) (7 ) (8 ) (9 ) = ( 8 ) / ( 5 ) (1 0 ) = ( 7 ) / ( 8 ) 33 2 . 0 0 RE S E R V O I R S , D A M S A N D W A T E R W A Y S M O N R O E S T R E E T 12 - 2 0 7 2 11 0 - R 1 * (7 ) 9,9 7 2 , 0 1 9 . 5 3 2, 0 2 9 , 3 2 7 8,6 4 0 , 7 3 4 18 9 , 6 5 2 1.9 0 45 . 6 L I T T L E F A L L S 12 - 2 0 5 9 11 0 - R 1 * (5 ) 6,3 7 9 , 5 5 2 . 4 6 3, 2 9 9 , 9 7 6 3,3 9 8 , 5 5 4 95 , 3 4 5 1.4 9 35 . 6 L O N G L A K E 12 - 2 0 5 5 11 0 - R 1 * (6 ) 37 , 6 9 4 , 8 7 4 . 9 7 16 , 2 7 0 , 7 0 1 23 , 6 8 5 , 8 6 6 73 4 , 5 4 6 1.9 5 32 . 2 S P O K A N E U P P E R F A L L S 12 - 2 0 6 0 11 0 - R 1 * (6 ) 7,7 2 8 , 5 7 3 . 3 9 3, 1 9 9 , 6 6 1 4,9 9 2 , 6 2 7 13 7 , 4 7 7 1.7 8 36 . 3 N I N E M I L E 12 - 2 0 6 0 11 0 - R 1 * (4 ) 30 , 7 9 2 , 7 7 1 . 9 0 (2 9 5 , 0 5 1 ) 32 , 3 1 9 , 5 3 4 88 6 , 4 5 2 2.8 8 36 . 5 P O S T F A L L S 12 - 2 0 6 0 11 0 - R 1 * (4 ) 24 , 3 5 5 , 8 7 0 . 1 1 4, 5 9 6 , 6 7 5 20 , 7 3 3 , 4 3 0 56 6 , 6 5 0 2.3 3 36 . 6 C A B I N E T G O R G E 12 - 2 0 7 2 11 0 - R 1 * (1 3 ) 26 , 8 4 0 , 9 6 2 . 1 9 10 , 0 1 5 , 8 2 3 20 , 3 1 4 , 4 6 5 45 9 , 4 0 6 1.7 1 44 . 2 N O X O N R A P I D S 12 - 2 0 7 9 11 0 - R 1 * (2 1 ) 32 , 6 0 0 , 3 1 7 . 9 1 13 , 0 9 6 , 4 3 9 26 , 3 4 9 , 9 4 5 55 3 , 7 0 1 1.7 0 47 . 6 TO T A L A C C O U N T 3 3 2 . 0 0 17 6 , 3 6 4 , 9 4 2 . 4 6 52 , 2 1 3 , 5 5 0 14 0 , 4 3 5 , 1 5 5 3,6 2 3 , 2 2 9 2.0 5 33 2 . 1 0 RE S E R V O I R S , D A M S A N D W A T E R W A Y S - F I S H A N D W I L D L I F E C O N S E R V A T I O N L O N G L A K E 12 - 2 0 5 5 65 - S 1 . 5 * (6 ) 83 , 7 8 0 . 6 2 10 , 1 5 2 78 , 6 5 5 2, 4 2 0 2.8 9 32 . 5 N I N E M I L E 12 - 2 0 6 0 65 - S 1 . 5 * (4 ) 82 , 4 5 7 . 9 3 8,9 4 3 76 , 8 1 3 2, 0 9 2 2.5 4 36 . 7 P O S T F A L L S 12 - 2 0 6 0 65 - S1. 5 * (4 ) 1,3 6 9 , 2 4 7 . 8 2 15 9 , 8 6 5 1,2 6 4 , 1 5 2 34 , 4 9 4 2.5 2 36 . 6 C A B I N E T G O R G E 12 - 2 0 7 2 65 - S 1 . 5 * (1 3 ) 16 , 3 5 3 , 51 1 . 4 9 4, 4 5 8 , 5 0 4 14 , 0 2 0 , 9 6 4 33 5 , 5 9 7 2.0 5 41 . 8 N O X O N R A P I D S 12 - 2 0 7 9 65 - S 1 . 5 * (2 1 ) 2,3 3 3 , 2 2 5 . 3 7 76 5 , 4 8 0 2,0 5 7 , 7 2 2 46 , 4 5 8 1.9 9 44 . 3 TO T A L A C C O U N T 3 3 2 . 1 0 20 , 2 2 2 , 2 2 3 . 2 3 5, 4 0 2 , 9 4 5 17 , 4 9 8 , 3 0 6 42 1 , 0 6 1 2.0 8 33 2 . 1 5 RE S E R V O I R S , D A M S A N D W A T E R W A Y S - F I S H A N D W I L D L I F E C O N S E R V A T I O N N I N E M I L E 12 - 2 0 6 0 65 - S 1 . 5 * (4 ) 11 , 0 3 4 . 0 0 1,2 9 1 10 , 1 8 4 27 9 2.5 3 36 . 5 C A B I N E T G O R G E 12 - 2 0 7 2 65 - S 1 . 5 * (1 3 ) 1,4 9 4 , 6 6 1 . 0 3 33 3 , 1 9 7 1,3 5 5 , 7 7 0 31 , 9 2 9 2.1 4 42 . 5 N O X O N R A P I D S 12 - 2 0 7 9 65 - S 1 . 5 * (2 1 ) 95 6 , 1 7 8 . 7 5 32 6 , 4 9 6 83 0 , 4 8 0 17 , 9 3 5 1.8 8 46 . 3 TO T A L A C C O U N T 3 3 2 . 1 5 2,4 6 1 , 8 7 3 . 7 8 66 0 , 9 8 4 2,1 9 6 , 4 3 4 50 , 1 4 3 2.0 4 33 2 . 2 0 RE S E R V O I R S , D A M S A N D W A T E R W A Y S - R E C R E A T I O N L I T T L E F A L L S 12 - 2 0 5 9 65 - S 1 . 5 * (5 ) 14 , 3 6 5 . 6 0 10 , 1 9 8 4,8 8 6 16 6 1.1 6 29 . 4 L O N G L A K E 12 - 2 0 5 5 65 - S 1 . 5 * (6 ) 10 5 , 6 3 9 . 4 3 10 2 , 3 7 0 9,6 0 8 34 7 0.3 3 27 . 7 N I N E M I L E 12 - 2 0 6 0 65 - S 1 . 5 * (4 ) 47 , 3 7 1 . 9 0 61 3 48 , 6 5 3 1, 6 1 2 3.4 0 30 . 2 P O S T F A L L S 12 - 2 0 6 0 65 - S 1 . 5 * (4 ) 33 8 , 8 7 0 . 4 5 39 , 2 4 7 31 3 , 17 9 9, 94 6 2.9 4 31 . 5 C A B I N E T G O R G E 12 - 2 0 7 2 65 - S 1 . 5 * (1 3 ) 10 2 , 5 7 0 . 3 5 61 , 5 5 6 54 , 3 4 9 1, 6 0 2 1.5 6 33 . 9 N O X O N R A P I D S 12 - 2 0 7 9 65 - S 1 . 5 * (2 1 ) 67 , 0 6 8 . 9 2 25 , 6 7 5 55 , 4 7 8 1, 5 3 4 2.2 9 36 . 2 TO T AL A C C O U N T 3 3 2 . 2 0 67 5 , 8 8 6 . 6 5 23 9 , 6 5 9 48 6 , 1 5 3 15 , 2 0 7 2.2 5 33 3 . 0 0 TU R B I N E S A N D G E N E R A T O R S M O N R O E S T R E E T 12 - 2 0 7 2 70 - S 0 * (7 ) 11 , 5 7 4 , 9 7 0 . 9 8 2, 9 7 2 , 5 0 5 9,4 1 2 , 7 1 4 24 7 , 0 9 9 2.1 3 38 . 1 L I T T L E F A L L S 12 - 2 0 5 9 70 - S 0 * (5 ) 39 , 2 0 0 , 5 3 9 . 2 6 7, 0 2 0 , 9 9 0 34 , 1 3 9 , 5 7 7 99 7 , 0 7 3 2.5 4 34 . 2 L O N G L A K E 12 - 2 0 5 5 70 - S 0 * (6 ) 8,7 3 5 , 7 9 8 . 6 1 8, 6 0 4 , 8 4 5 65 5 , 1 0 1 22 , 5 7 0 0.2 6 29 . 0 S P O K A N E U P P E R F A L L S 12 - 2 0 6 0 70 - S 0 * (6 ) 1,1 8 1 , 0 4 1 . 9 7 1, 2 0 9 , 7 4 4 42 , 1 6 1 1, 2 0 3 0.1 0 35 . 0 N I N E M I L E 12 - 2 0 6 0 70 - S 0 * (4 ) 41 , 1 3 4 , 4 6 7 . 9 9 (2 , 1 0 2 , 1 8 8 ) 44 , 8 8 2 , 0 3 4 1,3 0 2 , 4 8 8 3.1 7 34 . 5 P O S T F A L L S 12 - 2 0 6 0 70 - S 0 * (4 ) 2,2 3 3 , 6 5 0 . 8 7 2, 2 4 5 , 4 1 6 77 , 5 8 1 2, 4 1 7 0.1 1 32 . 1 C A B I N E T G O R G E 12 - 2 0 7 2 70 - S 0 * (1 3 ) 46 , 8 6 9 , 9 6 2 . 8 4 9, 6 6 5 , 0 4 2 43 , 2 9 8 , 0 1 6 1,0 9 6 , 1 9 2 2.3 4 39 . 5 N O X O N R A P I D S 12 - 2 0 7 9 70 - S 0 * (2 1 ) 88 , 8 2 2 , 3 3 0 . 2 1 23 , 7 4 0 , 0 2 8 83 , 7 3 4 , 9 9 2 1,9 5 1 , 95 7 2.20 42 . 9 TO T A L A C C O U N T 3 3 3 . 0 0 23 9 , 7 5 2 , 7 6 2 . 7 3 53 , 3 5 6 , 3 8 2 21 6 , 2 4 2 , 1 7 6 5,6 2 0 , 9 9 9 2.3 4 33 4 . 0 0 AC C E S S O R Y E L E C T R I C E Q U I P M E N T M O N R O E S T R E E T 12 - 2 0 7 2 40 - S 0 . 5 * (7 ) 3,0 3 4 , 2 4 2 . 4 9 22 6 , 2 7 3 3,0 2 0 , 3 6 7 11 3 , 4 1 8 3.7 4 26 . 6 L I T T L E F A L L S 12 - 2 0 5 9 40 - S 0 . 5 * (5 ) 13 , 9 6 3 , 8 6 8 . 8 2 2, 7 3 2 , 5 0 1 11 , 9 2 9 , 5 6 1 41 7 , 5 5 2 2.9 9 28 . 6 L O N G L A K E 12 - 2 0 5 5 40 - S 0 . 5 * (6 ) 4,5 0 4 , 0 4 1 . 4 9 2, 8 1 7 , 3 3 9 1,9 5 6 , 9 4 5 71 , 9 8 7 1.6 0 27 . 2 S P O K A N E U P P E R F A L L S 12 - 2 0 6 0 40 - S 0 . 5 * (6 ) 4,2 9 8 , 7 9 8 . 0 8 1, 2 1 8 , 4 1 1 3,3 3 8 , 3 1 5 12 7 , 9 4 7 2.9 8 26 . 1 N I N E M I L E 12 - 2 0 6 0 40 - S 0 . 5 * (4 ) 18 , 5 8 0 , 4 4 9 . 1 7 1, 8 3 9 , 5 2 0 17 , 4 8 4 , 1 4 7 61 4 , 6 0 3 3.3 1 28 . 4 P O S T F A L L S 12 - 2 0 6 0 40 - S 0 . 5 * (4 ) 2,4 4 8 , 2 7 3 . 6 8 77 6 , 4 7 7 1,7 6 9 , 7 2 8 61 , 7 2 3 2.5 2 28 . 7 C A B I N E T G O R G E 12 - 2 0 7 2 40 - S 0 . 5 * (1 3 ) 17 , 3 8 2 , 2 9 9 . 7 4 4, 0 5 4 , 9 5 4 15 , 5 8 7 , 0 4 5 47 1 , 2 8 5 2.7 1 33 . 1 N O X O N R A P I D S 12 - 2 0 7 9 40 - S 0 . 5 * (2 1 ) 19 , 6 1 5 , 7 6 1 . 0 9 3, 4 9 7 , 0 4 6 20 , 2 3 8 , 0 2 5 69 6 , 9 7 9 3.5 5 29 . 0 TO T A L A C C O U N T 3 3 4 . 0 0 83 , 8 2 7 , 7 3 4 . 5 6 17 , 1 6 2 , 5 2 1 75 , 3 2 4 , 1 3 3 2,5 7 5 , 4 9 4 3.0 7 33 5 . 0 0 MIS C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T M O N R O E S T R E E T 12 - 2 0 7 2 65 - R 1 * (7 ) 33 , 5 6 3 . 7 0 7,6 8 5 28 , 2 2 8 72 6 2.1 6 38 . 9 L I T T L E F A L L S 12 - 2 0 5 9 65 - R1 * (5 ) 54 8 , 9 4 8 . 4 5 13 3 , 9 8 3 44 2 , 4 1 3 13 , 2 0 2 2.4 0 33 . 5 L O N G L A K E 12 - 2 0 5 5 65 - R 1 * (6 ) 81 1 , 5 4 5 . 5 3 32 1 , 4 4 2 53 8 , 7 9 6 17 , 8 7 8 2.2 0 30 . 1 S P O K A N E U P P E R F A L L S 12 - 2 0 6 0 65 - R 1 * (6 ) 10 4 , 4 4 9 . 8 2 42 , 7 8 1 67 , 9 3 6 2, 1 1 7 2.0 3 32 . 1 N I N E M I L E 12 - 2 0 6 0 65 - R 1 * (4 ) 1,0 2 2 , 1 5 0 . 5 7 72 , 7 6 4 99 0 , 2 7 2 29 , 2 6 7 2.8 6 33 . 8 P O S T F A L L S 12 - 2 0 6 0 65 - R 1 * (4 ) 80 9 , 3 3 9 . 9 0 13 9 , 7 5 9 70 1 , 9 5 5 20 , 5 4 1 2.5 4 34 . 2 C A B I N E T G O R G E 12 - 2 0 7 2 65 - R 1 * (13 ) 5,3 2 0 , 0 3 5 . 0 5 2, 4 4 1 , 4 1 0 3,5 7 0 , 2 2 9 84 , 8 7 1 1.6 0 42 . 1 N O X O N R A P I D S 12 - 2 0 7 9 65 - R 1 * (2 1 ) 3,3 5 3 , 3 1 2 . 3 3 1, 5 6 2 , 3 8 4 2,4 9 5 , 1 2 4 58 , 8 1 1 1.7 5 42 . 4 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VI-6 Attachment C J. Spanos, Avista Page 60 of 800 AV I S T A C O R P O R A T I O N TA B L E 1 . S U M M A R Y O F E S T I M A T E D S U R V I V O R C U R V E , N E T S A L V A G E P E R C E N T , O R I G I N A L C O S T , B O O K D E P R E C I A T I O N R E S E R V E A N D CA L C U L A T E D A N N U A L D E P R E C I A T I O N A C C R U A L S R E L A T E D T O E L E C T R I C , G A S A N D C O M M O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 PR O B A B L E NE T OR I G I N A L C O S T BO O K FU T U R E CA L C U L A T E D CO M P O S I T E RE T I R E M E N T SU R V I V I O R SA L V A G E AS O F DE P R E C I A T I O N BO O K AN N U A L A C C R U A L RE M A I N I N G DE P R E C I A B L E G R O U P DA T E CU R V E PE R C E N T DE C E M B E R 3 1 , 2 0 2 1 RE S E R V E AC C R U A L S AM O U N T RA T E LIF E (1 ) (2 ) (3 ) (4 ) (5 ) (6 ) (7 ) (8 ) (9 ) = ( 8 ) / ( 5 ) (1 0 ) = ( 7 ) / ( 8 ) 33 5 . 1 0 MIS C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T - F I S H A N D W I L D L I F E C O N S E R V A T I O N C A B I N E T G O R G E 12 - 2 0 7 2 55 - R 3 * (1 3 ) 11 7 , 4 3 5 . 8 1 78 , 8 7 0 53 , 8 3 3 1, 4 0 9 1.2 0 38 . 2 N O X O N R A P I D S 12 - 2 0 7 9 55 - R 3 * (2 1 ) 35 5 , 9 8 0 . 0 2 28 6 , 0 4 7 14 4 , 6 8 9 4, 1 4 1 1.1 6 34 . 9 TO T A L A C C O U N T 3 3 5 . 1 0 47 3 , 4 1 5 . 8 3 36 4 , 9 1 6 19 8 , 5 2 2 5, 5 5 0 1.1 7 33 5 . 1 5 MIS C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T - F I S H A N D W I L D L I F E C O N S E R V A T I O N L O N G L A K E 12 - 2 0 5 5 55 - R 3 * (6 ) 14 , 5 9 2 . 1 3 47 2 14 , 9 9 6 45 6 3.1 2 32 . 9 P O S T F A L L S 12 - 2 0 6 0 55 - R 3 * (4 ) 16 , 9 2 5 . 0 6 33 0 17 , 2 7 2 46 4 2.7 4 37 . 2 C A B I N E T G O R G E 12 - 2 0 7 2 55 - R 3 * (1 3 ) 24 6 , 7 0 7 . 6 6 12 , 9 8 2 26 5 , 7 9 8 5, 8 5 2 2.3 7 45 . 4 N O X O N R A P I D S 12 - 2 0 7 9 55 - R 3 * (2 1 ) 57 8 , 6 2 9 . 8 5 23 , 2 7 7 67 6 , 8 6 5 14 , 2 3 0 2.4 6 47 . 6 TO T A L A C C O U N T 3 3 5 . 1 5 85 6 , 8 5 4 . 7 0 37 , 0 6 1 97 4 , 9 3 1 21 , 0 0 2 2.4 5 33 5 . 2 0 MIS C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T - R E C R E A T I O N L O N G L A K E 12 - 2 0 5 5 55 - R 3 * (6 ) 25 , 6 9 7 . 1 4 22 3 27 , 0 1 6 81 8 3.1 8 33 . 0 N I N E M I L E 12 - 2 0 6 0 55 - R 3 * (4 ) 18 , 7 4 1 . 2 1 95 6 18 , 5 3 5 51 4 2.7 4 36 . 1 C A B I N E T G O R G E 12 - 2 0 7 2 55 - R 3 * (1 3 ) 49 , 3 0 8 . 3 3 24 , 5 3 3 31 , 1 8 5 71 1 1.4 4 43 . 9 N O X O N R A P I D S 12 - 2 0 7 9 55 - R 3 * (2 1 ) 45 , 38 8 . 32 7,0 9 1 47 , 8 2 9 1, 0 8 2 2.3 8 44 . 2 TO T A L A C C O U N T 3 3 5 . 2 0 13 9 , 1 3 5 . 0 0 32 , 8 0 2 12 4 , 5 6 5 3, 1 2 5 2.2 5 33 6 . 0 0 RO A DS , R A I L R O A D S A N D B R I D G E S M O N R O E S T R E E T 12 - 2 0 7 2 60 - S 2 . 5 * (7 ) 50 , 4 4 8 . 4 4 14 , 7 4 5 39 , 2 3 5 1, 2 6 8 2.5 1 30 . 9 S P O K A N E U P P E R F A L L S 12 - 2 0 6 0 60 - S 2 . 5 * (6 ) 50 8 , 2 4 2 . 3 4 74 , 7 5 1 46 3 , 9 8 6 12 , 6 2 2 2.4 8 36 . 8 N I N E M I L E 12 - 2 0 6 0 60 - S 2 . 5 * (4 ) 59 4 , 8 7 0 . 0 6 20 7 , 9 4 8 41 0 , 7 1 7 13 , 9 6 9 2.3 5 29 . 4 P O S T F A L L S 12 - 2 0 6 0 60 - S 2 . 5 * (4 ) 57 7 , 9 4 3 . 7 2 53 , 3 2 2 54 7 , 7 3 9 14 , 5 8 3 2.5 2 37 . 6 C A B I N E T G O R G E 12 - 2 0 7 2 60 - S 2 . 5 * (1 3 ) 1,6 7 1 , 0 1 2 . 5 8 1, 1 2 8 , 0 3 4 76 0 , 2 1 0 21 , 2 4 8 1. 2 7 35 . 8 N O X O N R A P I D S 12 - 2 0 7 9 60 - S 2 . 5 * (2 1 ) 25 9 , 7 4 9 . 6 3 14 0 , 0 5 7 17 4 , 2 4 0 5, 8 3 5 2.2 5 29 . 9 TO T A L A C C O U N T 3 3 6 . 0 0 3,6 6 2 , 2 6 6 . 7 7 1, 6 1 8 , 8 5 6 2,3 9 6 , 1 2 7 69 , 5 2 5 1.9 0 TO T A L H Y D R O P R O D U C T I O N P L A N T 69 4 , 9 0 4 , 4 7 3 . 4 5 17 4 , 7 5 7 , 0 3 3 59 1 , 7 1 4 , 8 4 1 15 , 7 6 7 , 0 9 0 2.2 7 OT H E R P R O D U C T I O N P L A N T 34 1 . 0 0 ST R U C T U R E S A N D I M P R O V E M E N T S K E T T L E F A L L S 12 - 2 0 3 8 55 - R 4 * (1 ) 9,0 2 8 . 8 0 3,2 8 9 5,8 3 0 34 4 3.8 1 16 . 9 N O R T H E A S T T U R B I N E 12 - 2 0 3 5 55 - R 4 * (7 ) 75 1 , 0 2 5 . 3 5 77 9 , 1 1 2 24 , 4 8 5 1, 7 5 5 0.2 3 14 . 0 B O U L D E R P A R K 12 - 2 0 4 2 55 - R 4 * (1 ) 1,2 7 3 , 8 9 1 . 9 5 59 8 , 5 5 3 68 8 , 0 7 8 33 , 4 7 6 2.6 3 20 . 6 R A T H D R U M T U R B I N E 12 - 2 0 3 4 55 - R 4 * (4 ) 3,5 8 4 , 5 0 1 . 9 3 1, 9 1 3 , 6 3 2 1,8 1 4 , 2 5 0 14 0 , 6 0 4 3.9 2 12 . 9 C O Y O T E S P R I N G S 2 12 - 2 0 4 3 55 - R 4 * (3 ) 11 , 7 5 7 , 9 2 5 . 2 1 5, 7 8 6 , 4 0 8 6,3 2 4 , 2 5 5 29 5 , 9 1 3 2.5 2 21 . 4 TO T A L A C C O U N T 3 4 1 . 0 0 17 , 3 7 6 , 3 7 3 . 2 4 9, 0 8 0 , 9 9 4 8,8 5 6 , 8 9 8 47 2 , 0 9 2 2.7 2 34 2 . 0 0 FU E L H O L D E R S , P R O D U C E R S A N D A C C E S S O R I E S K E T T L E F A L L S 12 - 2 0 3 8 55 - R 3 * (1 ) 89 , 2 3 2 . 1 9 70 , 5 0 8 19 , 6 1 7 1, 2 0 3 1.3 5 16 . 3 N O R T H E A S T T U R B I N E 12 - 2 0 3 5 55 - R 3 * (7 ) 36 , 8 9 6 . 8 4 36 , 5 1 2 2,9 6 7 21 3 0.5 8 13 . 9 B O U L D E R P A R K 12 - 2 0 4 2 55 - R 3 * (1 ) 16 2 , 1 4 3 . 4 4 16 , 0 9 3 14 7 , 6 7 2 7, 1 5 9 4.4 2 20 . 6 R A T H D R U M T U R B I N E 12 - 2 0 3 4 55 - R 3 * (4 ) 1,6 9 5 , 8 0 8 . 4 0 1, 0 0 3 , 6 2 0 76 0 , 0 2 1 59 , 7 4 5 3.5 2 12 . 7 L A N C A S T E R 12 - 2 0 4 0 55 - R 3 * (3 ) 91 , 9 7 7 . 9 2 45 , 6 4 2 49 , 0 9 5 2, 6 4 9 2.8 8 18 . 5 C O Y O T E S P R I N G S 2 12 - 2 0 4 3 55 - R3 * (3 ) 19 , 0 0 0 , 2 8 9 . 1 0 10 , 2 2 2 , 9 2 4 9,3 4 7 , 3 7 3 44 8 , 8 8 8 2.3 6 20 . 8 TO T A L A C C O U N T 3 4 2 . 0 0 21 , 0 7 6 , 3 4 7 . 8 9 11 , 3 9 5 , 2 9 9 10 , 3 2 6 , 7 4 5 51 9 , 85 7 2.4 7 34 3 . 0 0 PR I M E M O V E R S K E T T L E F A L L S 12 - 2 0 3 8 60 - S 2 * (1 ) 8,6 7 0 , 0 8 4 . 3 8 6, 4 5 4 , 4 1 0 2,3 0 2 , 3 7 6 14 0 , 9 0 4 1.6 3 16 . 3 N O R T H E A S T T U R B I N E 12 - 2 0 3 5 60 - S 2 * (7 ) 9,0 5 8 , 2 7 4 . 2 2 9, 3 1 4 , 9 5 7 37 7 , 3 9 7 27 , 7 5 7 0.3 1 13 . 6 B O U L D E R P A R K 12 - 2 0 4 2 60 - S 2 * (1 ) 57 , 2 1 6 . 2 8 30 , 8 5 1 26 , 9 3 7 1, 3 4 2 2.3 5 20 . 1 R A T H D R U M T U R B I N E 12 - 2 0 3 4 60 - S 2 * (4 ) 3,6 5 8 , 3 2 8 . 0 3 2, 9 9 9 , 0 1 3 80 5 , 6 4 8 63 , 5 9 9 1.7 4 12 . 7 TO T A L A C C O U N T 3 4 3 . 0 0 21 , 4 4 3 , 9 0 2 . 9 1 18 , 7 9 9 , 2 3 0 3,5 1 2 , 3 5 8 23 3 , 6 0 2 1.0 9 34 4 . 0 0 GE N E R A T O R S K E T T L E F A L L S 12 - 2 0 3 8 50 - R 1 * (1 ) 23 4 , 2 6 0 . 9 3 59 , 4 6 7 17 7 , 1 3 6 11 , 0 3 6 4. 7 1 16 . 1 N O R T H E A S T T U R B I N E 12 - 2 0 3 5 50 - R 1 * (7 ) 2,8 5 6 , 6 6 7 . 4 2 2, 6 9 2 , 1 8 2 36 4 , 4 5 3 27 , 5 4 0 0. 9 6 13 . 2 B O U L D E R P A R K 12 - 2 0 4 2 50 - R 1 * (1 ) 31 , 3 7 0 , 4 5 9 . 0 6 18 , 4 8 5 , 7 1 8 13 , 1 9 8 , 4 4 6 70 4 , 4 3 6 2. 2 5 18 . 7 R A T H D R U M T U R B I N E 12 - 2 0 3 4 50 - R 1 * (4 ) 51 , 2 0 2 , 4 7 2 . 4 3 29 , 0 4 7 , 8 1 9 24 , 2 0 2 , 7 5 3 1,9 7 5 , 7 1 1 3. 8 6 12 . 3 L A N C A S T E R 12 - 2 0 4 0 50 - R 1 * (3 ) 20 8 , 5 0 5 . 8 2 98 , 9 0 8 11 5 , 85 3 6, 62 0 3.1 7 17 . 5 C O Y O T E S P R I N G S 2 12 - 2 0 4 3 50 - R 1 * (3 ) 15 3 , 9 1 5 , 8 5 4 . 3 6 54 , 6 9 9 , 5 8 3 10 3 , 8 3 3 , 7 4 7 5,2 2 7 , 7 1 2 3.4 0 19 . 9 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VI-7 Attachment C J. Spanos, Avista Page 61 of 800 AV I S T A C O R P O R A T I O N TA B L E 1 . S U M M A R Y O F E S T I M A T E D S U R V I V O R C U R V E , N E T S A L V A G E P E R C E N T , O R I G I N A L C O S T , B O O K D E P R E C I A T I O N R E S E R V E A N D CA L C U L A T E D A N N U A L D E P R E C I A T I O N A C C R U A L S R E L A T E D T O E L E C T R I C , G A S A N D C O M M O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 PR O B A B L E NE T OR I G I N A L C O S T BO O K FU T U R E CA L C U L A T E D CO M P O S I T E RE T I R E M E N T SU R V I V I O R SA L V A G E AS O F DE P R E C I A T I O N BO O K AN N U A L A C C R U A L RE M A I N I N G DE P R E C I A B L E G R O U P DA T E CU R V E PE R C E N T DE C E M B E R 3 1 , 2 0 2 1 RE S E R V E AC C R U A L S AM O U N T RA T E LIF E (1 ) (2 ) (3 ) (4 ) (5 ) (6 ) (7 ) (8 ) (9 ) = ( 8 ) / ( 5 ) (1 0 ) = ( 7 ) / ( 8 ) 34 4 . 0 1 GE N E R A T O R S - S O L A R C E N T R A L O P E R A T I O N S F A C I L I T Y 12 - 2 0 2 9 25 - S 2 . 5 * (3 ) 44 9 , 1 7 2 . 2 3 21 6 , 2 2 5 24 6 , 4 2 3 31 , 9 1 5 7.1 1 7.7 B O U L D E R P A R K 12 - 2 0 4 2 25 - S 2 . 5 * (1 ) 22 , 4 8 1 . 6 2 1,8 4 5 20 , 8 6 1 1, 2 0 0 5.3 4 17 . 4 TO T A L A C C O U N T 3 4 4 . 0 1 47 1 , 6 5 3 . 8 5 21 8 , 0 7 0 26 7 , 2 8 4 33 , 1 1 5 7.0 2 34 5 . 0 0 AC C E S S O R Y E L E C T R I C E Q U I P M E N T K E T T L E F A L L S 12 - 2 0 3 8 30 - S 0 . 5 * (1 ) 53 8 , 5 2 2 . 6 4 12 , 7 5 3 53 1 , 1 5 5 33 , 5 4 7 6.2 3 15 . 8 N O R T H E A S T T U R B I N E 12 - 2 0 3 5 30 - S 0 . 5 * (7 ) 1,2 4 3 , 0 6 0 . 5 3 1, 3 1 6 , 0 9 7 13 , 9 7 8 1, 1 3 4 0.0 9 12 . 3 B O U L D E R P A R K 12 - 2 0 4 2 30 - S 0 . 5 * (1 ) 92 4 , 8 0 3 . 3 6 22 7 , 0 8 0 70 6 , 9 7 1 40 , 6 4 0 4.3 9 17 . 4 R A T H D R U M T U R B I N E 12 - 2 0 3 4 30 - S 0 . 5 * (4 ) 4,8 0 8 , 0 6 9 . 6 5 1, 2 5 1 , 4 0 2 3,7 4 8 , 9 9 0 31 7 , 9 7 1 6.6 1 11 . 8 L A N C A S T E R 12 - 2 0 4 0 30 - S 0 . 5 * (3 ) 30 8 , 0 8 0 . 3 8 22 , 7 4 1 29 4 , 5 8 1 17 , 0 9 9 5.5 5 17 . 2 C O Y O T E S P R I N G S 2 12 - 2 0 4 3 30 - S 0 . 5 * (3 ) 17 , 8 8 6 , 3 7 2 . 0 1 11 , 3 0 1 , 5 1 0 7,1 2 1 , 4 5 3 43 9 , 9 7 8 2.4 6 16 . 2 TO T A L A C C O U N T 3 4 5 . 0 0 25 , 7 0 8 , 9 0 8 . 5 7 14 , 1 3 1 , 5 8 4 12 , 4 1 7 , 1 2 8 85 0 , 3 6 9 3.3 1 34 5 . 0 1 AC C E S S O R Y E L E C T R I C E Q U I P M E N T - S O L A R C E N T R A L O P E R A T I O N S F A C I L I T Y 12 - 2 0 2 9 25 - S 2 . 5 * (3 ) 33 , 2 0 9 . 4 1 11 , 7 0 1 22 , 5 0 5 2, 9 6 1 8.9 2 7. 6 34 6 . 0 0 MIS C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T N O R T H E A S T T U R B I N E 12 - 2 0 3 5 35 - R 2 * (7) 39 8 , 9 9 7 . 4 4 41 6 , 4 9 3 10 , 4 3 4 79 9 0.2 0 13 . 1 B O U L D E R P A R K 12 - 2 0 4 2 35 - R 2 * (1 ) 64 , 6 5 2 . 42 8,6 6 8 56 , 6 3 1 2, 9 2 4 4.5 2 19 . 4 R A T H D R U M T U R B I N E 12 - 2 0 3 4 35 - R 2 * (4 ) 24 9 , 4 7 2 . 2 1 75 , 2 4 9 18 4 , 2 0 2 14 , 8 6 7 5.9 6 12 . 4 C O Y O T E S P R I N G S 2 12 - 2 0 4 3 35 - R 2 * (3 ) 93 5 , 1 7 2 . 6 2 24 0 , 6 6 6 72 2 , 5 6 2 41 , 0 2 5 4.3 9 17 . 6 TO T A L A C C O U N T 3 4 6 . 0 0 1,6 4 8 , 2 9 4 . 6 9 74 1 , 0 7 7 97 3 , 8 2 9 59 , 6 1 5 3.6 2 TO T A L O T H E R P R O D U C T I O N P L A N T 32 7 , 5 4 6 , 9 1 0 . 5 8 15 9 , 4 6 1 , 6 3 0 17 8 , 2 6 9 , 1 3 5 10 , 1 2 4 , 6 6 6 3.0 9 TR A N S M I S S I O N P L A N T 35 0 . 3 0 RE M O V I N G P R O P E R T Y O F O T H E R S 80 - R 4 0 1,4 8 7 , 5 6 5 . 9 1 80 8 , 5 2 6 67 9 , 0 4 0 15 , 5 1 9 1.0 4 43 . 8 35 0 . 4 0 LA N D R I G H T S 80 - R 4 0 21 , 3 7 0 , 1 6 6 . 3 5 6, 1 0 9 , 2 5 7 15 , 2 6 0 , 9 0 9 25 2 , 6 5 4 1.1 8 60 . 4 35 2 . 0 0 ST R U C T U R E S A N D I M P R O V E M E N T S 65 - S 2 (1 5 ) 30 , 9 5 8 , 1 8 8 . 5 8 7, 7 4 7 , 5 8 2 27 , 8 5 4 , 3 3 4 54 5 , 6 6 8 1.7 6 51 . 0 35 3 . 0 0 ST A T I O N E Q U I P M E N T 46 - R 2 (1 0 ) 35 4 , 7 6 1 , 2 3 6 . 3 8 95 , 1 0 1 , 3 8 5 29 5 , 1 3 5 , 9 7 5 8,2 9 8 , 1 9 5 2.3 4 35 . 6 35 4 . 0 0 TO W E R S A N D F I X T U R E S 80 - R 4 (1 0 ) 17 , 2 7 8 , 3 8 3 . 7 9 10 , 9 0 1 , 4 1 1 8,1 0 4 , 8 1 1 18 9 , 1 9 1 1.0 9 42 . 8 35 5 . 0 0 PO L E S A N D F I X T U R E S 60 - R 2 . 5 (4 0 ) 33 3 , 6 6 8 , 3 5 4 . 1 7 77 , 1 0 5 , 7 8 9 39 0 , 0 2 9 , 9 0 7 8,0 1 7 , 6 3 3 2.4 0 48 . 6 35 6 . 0 0 OV E R H E A D C O N D U C T O R S A N D D E V I C E S 60 - R 3 (3 0 ) 17 5 , 2 6 2 , 3 3 6 . 9 9 51 , 8 8 0 , 5 4 8 17 5 , 9 6 0 , 4 9 0 4,4 2 5 , 9 9 6 2.5 3 39 . 8 35 7 . 0 0 UN D E R G R O U N D C O N D U I T 60 - R 4 0 3,5 2 4 , 6 8 4 . 9 7 92 4 , 7 2 2 2,5 9 9 , 9 6 3 57 , 3 8 8 1.6 3 45 . 3 35 8 . 0 0 UN D E R G R O U N D C O N D U C T O R S A N D D E V I C E S 50 - S 3 0 7,2 9 5 , 3 8 6 . 9 6 88 1 , 8 9 2 6,4 1 3 , 4 9 5 15 2 , 0 8 8 2.0 8 42 . 2 35 9 . 0 0 RO A D S A N D T R A I L S 75 - R 4 0 2,5 7 6 , 2 0 1 . 2 9 99 3 , 5 6 9 1, 5 8 2 , 6 3 2 31 , 7 2 3 1. 2 3 49 . 9 TO T A L T R A N S M I S S I O N P L A N T 94 8 , 1 8 2 , 5 0 5 . 3 9 25 2 , 4 5 4 , 6 8 2 92 3 , 6 2 1 , 5 5 6 21 , 9 8 6 , 0 5 5 2.3 2 DIS T R I B U T I O N P L A N T 36 0 . 4 0 LA N D - E A S E M E N T S 75 - R 4 0 3,9 1 9 , 2 3 9 . 3 2 38 7 , 3 2 5 3,5 3 1 , 9 1 5 52 , 4 6 8 1.3 4 67 . 3 36 1 . 0 0 ST R U C T U R E S A N D I M P R O V E M E N T S 63 - S 1 (1 5 ) 28 , 8 3 3 , 8 1 0 . 2 9 8, 1 8 7 , 8 0 8 24 , 9 7 1 , 0 7 4 49 7 , 2 3 0 1.7 2 50 . 2 36 2 . 0 0 ST A T I O N E Q U I P M E N T 43 - R 1 . 5 (1 0 ) 16 2 , 5 3 5 , 4 7 7 . 0 1 46 , 8 3 7 , 4 5 6 13 1 , 9 5 1 , 5 6 9 4,1 9 4 , 7 3 3 2.5 8 31 . 5 36 4 . 0 0 PO L E S , T O W E R S A N D F I X T U R E S 63 - R 3 (6 0 ) 49 7 , 6 7 8 , 9 9 1 . 4 9 13 8 , 2 5 1 , 0 4 2 65 8 , 0 3 5 , 3 4 4 13 , 4 0 8 , 4 6 2 2.6 9 49 . 1 36 5 . 0 0 OV E R H E A D C O N D U C T O R S A N D D E V I C E S 65 - R 3 (5 5 ) 31 9 , 7 0 1 , 3 0 2 . 6 7 10 1 , 3 6 8 , 4 8 7 39 4 , 1 6 8 , 5 3 3 7,8 5 6 , 5 0 3 2.4 6 50 . 2 36 6 . 0 0 UN D E R G R O U N D C O N D U I T 65 - S 2 . 5 (2 5 ) 14 4 , 2 8 2 , 5 8 1 . 9 9 44 , 2 8 4 , 5 1 5 13 6 , 0 6 8 , 7 1 3 2,6 2 6 , 0 9 0 1.8 2 51 . 8 36 7 . 0 0 UN D E R G R O U N D C O N D U C T O R S A N D D E V I C E S 40 - S 1 . 5 (2 5 ) 25 2 , 1 4 3 , 3 9 9 . 0 5 12 7 , 2 4 7 , 8 0 6 18 7 , 9 3 1 , 4 4 3 6,1 3 2 , 1 1 5 2.4 3 30 . 6 36 8 . 0 0 LIN E T R A N S F O R M E R S 50 - R 2 . 5 (1 0 ) 30 8 , 0 8 0 , 4 4 2 . 0 2 10 9 , 8 2 6 , 3 5 9 22 9 , 0 6 2 , 1 2 7 6,2 4 2 , 8 4 3 2.0 3 36 . 7 SE R V I C E S 36 9 . 1 0 O V E R H E A D 70 - R 4 (3 5 ) 66 , 5 1 1 , 4 6 6 . 0 3 33 , 7 3 0 , 7 9 0 56 , 0 5 9 , 6 9 0 1,1 0 3 , 4 8 8 1.6 6 50 . 8 36 9 . 2 0 U N D E R G R O U N D - S P O K A N E N E T W O R K 70 - R 4 (3 5 ) 8,6 0 0 , 8 9 2 . 2 1 1, 6 6 0 , 8 6 4 9,9 5 0 , 3 4 0 16 0 , 9 0 0 1.8 7 61 . 8 36 9 . 3 0 U N D E R G R O U N D - O T H E R 70 - R 4 (3 5 ) 12 6 , 2 0 3 , 6 3 5 . 5 3 47 , 3 3 8 , 4 5 7 12 3 , 0 3 6 , 4 5 1 2,2 1 7 , 6 2 6 1.7 6 55 . 5 T O T A L S E R V I C E S 20 1 , 3 1 5 , 9 9 3 . 7 7 82 , 7 3 0 , 1 1 1 18 9 , 0 4 6 , 4 8 1 3,4 8 2 , 0 1 4 1.7 3 ME T E R S 37 0 . 1 0 IDA H O 12 - 2 0 2 8 33 - L 1 . 5 (2 ) 24 , 5 0 6 , 3 9 9 . 4 2 16 , 1 7 2 , 3 7 2 8,8 2 4 , 1 5 5 1,3 6 4 , 3 6 5 5.5 7 6.5 37 0 . 3 0 W A S H I N G T O N S T A N D A R D 12 - L 2 . 5 (2 ) 1,0 2 7 , 4 8 0 . 2 4 29 6 , 8 4 1 75 1 , 1 8 9 80 , 75 8 7.8 6 9.3 37 0 . 4 0 W A S H I N G T O N A M I 15 - S 2 . 5 (2 ) 59 , 4 4 7 , 4 0 2 . 7 1 8, 5 5 1 , 3 2 9 52 , 0 8 5 , 0 2 2 4,4 7 8 , 6 0 2 7.5 3 11 . 6 T O T A L M E T E R S 84 , 9 8 1 , 2 8 2 . 3 7 25 , 0 2 0 , 5 4 1 61 , 6 6 0 , 3 6 6 5,9 2 3 , 7 2 5 6.9 7 37 1 . 0 0 IN S T A L L A T I O N S O N C U S T O M E R S ' P R E M I S E S - C A T A L Y S T B U I L D I N G 35 - R 3 0 60 4 , 9 8 6 . 5 1 23 , 6 3 2 58 1 , 3 5 4 17 , 3 1 8 2.8 6 33 . 6 EL E C T R I C V E H I C L E C H A R G I N G S T A T I O N 37 1 . 0 1 R E S I D E N T I A L 10 - S 3 0 2,5 7 2 , 4 6 1 . 2 2 71 7 , 0 9 7 1,8 5 5 , 3 6 4 27 9 , 5 0 1 10 . 8 7 6. 6 37 1 . 0 2 M U L T I - U N I T D W E L L I N G S 10 - S 3 0 16 5 , 8 9 6 . 4 7 10 6 , 8 0 0 59 , 0 9 7 12 , 6 5 5 7.6 3 4. 7 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VI-8 Attachment C J. Spanos, Avista Page 62 of 800 AV I S T A C O R P O R A T I O N TA B L E 1 . S U M M A R Y O F E S T I M A T E D S U R V I V O R C U R V E , N E T S A L V A G E P E R C E N T , O R I G I N A L C O S T , B O O K D E P R E C I A T I O N R E S E R V E A N D CA L C U L A T E D A N N U A L D E P R E C I A T I O N A C C R U A L S R E L A T E D T O E L E C T R I C , G A S A N D C O M M O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 PR O B A B L E NE T OR I G I N A L C O S T BO O K FU T U R E CA L C U L A T E D CO M P O S I T E RE T I R E M E N T SU R V I V I O R SA L V A G E AS O F DE P R E C I A T I O N BO O K AN N U A L A C C R U A L RE M A I N I N G DE P R E C I A B L E G R O U P DA T E CU R V E PE R C E N T DE C E M B E R 3 1 , 2 0 2 1 RE S E R V E AC C R U A L S AM O U N T RA T E LIF E (1 ) (2 ) (3 ) (4 ) (5 ) (6 ) (7 ) (8 ) (9 ) = ( 8 ) / ( 5 ) (1 0 ) = ( 7 ) / ( 8 ) ST R E E T L I G H T I N G A N D S I G N A L S Y S T E M S 37 3 . 1 0 M E R C U R Y V A P O R 33 - S 1 (1 5 ) 4,5 4 2 , 1 7 6 . 9 3 4, 6 5 0 , 4 7 9 57 3 , 0 2 4 35 , 5 8 0 0.7 8 16 . 1 37 3 . 2 0 U N D E R G R O U N D C O N D U C T O R 33 - S 1 (1 5 ) 5,7 6 7 , 3 4 4 . 9 2 2, 7 7 5 , 2 6 1 3,8 5 7 , 1 8 6 15 5 , 8 0 6 2.7 0 24 . 8 37 3 . 3 0 D E C O R A T I V E A N D M E T A L S T A N D A R D S 33 - S 1 (1 5 ) 17 , 1 6 4 , 1 2 0 . 5 7 6, 5 5 0 , 0 0 1 13 , 1 8 8 , 7 3 7 53 1 , 7 4 8 3.1 0 24 . 8 37 3 . 4 0 H I G H P R E S S U R E S O D I U M V A P O R 33 - S 1 (1 5 ) 29 , 5 2 4 , 1 7 9 . 9 3 6, 3 3 1 , 3 7 5 27 , 6 2 1 , 4 3 2 1,1 0 6 , 7 9 4 3.7 5 25 . 0 37 3 . 5 0 L E D 33 - S 1 (1 5 ) 17 , 9 7 0 , 6 9 3 . 0 9 3, 7 9 2 , 0 5 8 16 , 8 7 4 , 2 3 9 58 6 , 0 5 7 3.2 6 28 . 8 T O T A L S T R E E T L I G H T I N G A N D S I G N A L S Y S T E M S 74 , 9 6 8 , 5 1 5 . 4 4 24 , 0 9 9 , 1 7 4 62 , 1 1 4 , 6 1 8 2,4 1 5 , 9 8 5 3.2 2 TO T A L D I S T R I B U T I O N P L A N T 2,0 8 1 , 7 8 4 , 3 7 9 . 6 2 70 9 , 0 8 8 , 1 5 2 2,0 8 1 , 0 3 7 , 9 9 8 53 , 1 4 1 , 6 4 2 2.5 5 GE N E R A L P L A N T 39 0 . 1 0 ST R U C T U R E S A N D I M P R O V E M E N T S - C O M P A N Y 50 - S 1 (5 ) 17 , 8 7 1 , 7 8 4 . 7 6 2, 4 0 1 , 2 0 2 16 , 3 6 4 , 1 7 2 36 8 , 0 8 2 2.0 6 44 . 5 OF F I C E F U R N I T U R E A N D E Q U I P M E N T 39 1 . 0 0 FU R N I T U R E A N D E Q U I P M E N T 15 - S Q 0 33 , 0 3 8 . 6 6 2,1 4 1 30 , 8 9 8 2, 2 0 3 6.6 7 14 . 0 39 1 . 1 0 CO M P U T E R H A R D W A R E 5-S Q 0 1,6 3 6 , 3 7 4 . 2 8 61 3 , 2 5 0 1,0 2 3 , 1 2 4 32 7 , 3 0 3 20 . 0 0 3.1 39 1 . 1 2 CO M P U T E R H A R D W A R E - A M I 5-S Q 0 32 6 , 2 4 9 . 4 7 16 3 , 1 1 5 16 3 , 1 3 4 65 , 2 5 4 20 . 0 0 2.5 T O T A L O F F I C E F U R N I T U R E A N D E Q U I P M E N T 1,9 9 5 , 6 6 2 . 4 1 77 8 , 5 0 6 1,2 1 7 , 1 5 6 39 4 , 7 6 0 19 . 7 8 TR A N S P O R T A T I O N E Q U I P M E N T 39 2 . 2 0 L I G H T T R U C K S 14 - L 2 . 5 10 8,0 6 9 , 7 0 8 . 6 9 4, 2 0 8 , 9 8 9 3,0 5 3 , 7 4 9 33 6 , 6 8 0 4.1 7 9.1 39 2 . 3 0 M E D I U M T R U C K S 17 - L 2 . 5 10 25 , 9 6 8 , 4 2 8 . 6 9 11 , 0 0 1 , 9 3 0 12 , 3 6 9 , 6 5 6 99 0 , 5 0 8 3.8 1 12 . 5 39 2 . 4 0 H E A V Y T R U C K S 20 - R 4 10 12 , 7 6 4 , 8 1 2 . 1 0 4, 3 2 5 , 5 8 2 7,1 6 2 , 7 4 9 50 3 , 0 1 6 3.9 4 14 . 2 39 2 . 5 0 O T H E R 16 - L 2 10 8,2 9 0 , 9 2 1 . 4 9 3, 3 1 7 , 4 0 5 4,1 4 4 , 4 2 4 39 2 , 0 9 9 4.7 3 10 . 6 T O T A L T R A N S P O R T A T I O N E Q U I P M E N T 55 , 0 9 3 , 8 7 0 . 9 7 22 , 8 5 3 , 9 0 5 26 , 7 3 0 , 5 7 8 2,2 2 2 , 3 0 3 4.0 3 39 3 . 0 0 ST O R E S E Q U I P M E N T 25 - S Q 0 47 2 , 7 8 3 . 3 6 20 3 , 7 5 8 26 9 , 0 2 5 18 , 9 1 2 4.0 0 14 . 2 TO O L S , S H O P A N D G A R A G E E Q U I P M E N T 39 4 . 0 0 T O O L S , S H O P A N D G A R A G E E Q U I P M E N T 20 - S Q 0 7,3 9 6 , 2 7 5 . 8 9 2, 1 3 4 , 0 5 4 5,2 6 2 , 2 2 2 36 9 , 5 8 2 5.0 0 14 . 2 39 4 . 1 0 E L E C T R I C V E H I C L E C H A R G E R 10 - S 2 . 5 0 11 7 , 2 3 0 . 0 9 61 , 1 3 4 56 , 09 6 11 , 14 7 9.5 1 5.0 T O T A L T O O L S , S H O P A N D G A R A G E E Q U I P M E N T 7,5 1 3 , 5 0 5 . 9 8 2, 1 9 5 , 1 8 8 5,3 1 8 , 3 1 8 38 0 , 7 2 9 5.0 7 LA B O R A T O R Y E Q U I P M E N T 39 5 . 0 0 LA B O R A T O R Y E Q U I P M E N T 15 - S Q 0 2,90 1 , 5 0 0 . 2 0 48 5 , 9 9 4 2,4 1 5 , 5 0 6 19 3 , 4 3 4 6.6 7 12 . 5 39 5 . 1 2 LA B O R A T O R Y E Q U I P M E N T - A M I 15 - S Q 0 25 3 , 8 8 3 . 4 5 58 , 5 1 9 19 5 , 3 6 4 16 , 9 3 5 6.6 7 11 . 5 T O T A L L A B O R A T O R Y E Q U I P M E N T 3,1 5 5 , 3 8 3 . 6 5 54 4 , 5 1 3 2,6 1 0 , 8 7 0 21 0 , 3 6 9 6.6 7 PO W E R O P E R A T E D E Q U I P M E N T 39 6 . 3 0 M E D I U M T R U C K S 16 - L 2 0 4,3 2 9 , 9 0 3 . 2 1 3, 1 7 1 , 9 8 2 1,1 5 7 , 9 2 1 15 8 , 3 4 5 3.6 6 7.3 39 6 . 4 0 H E A V Y T R U C K S 24 - S 1 0 21 , 8 6 9 , 3 2 0 . 0 6 16 , 0 7 7 , 9 6 4 5,7 9 1 , 3 5 6 41 1 , 4 7 2 1.8 8 14 . 1 39 6 . 5 0 O T H E R 16 - S 0 0 4,0 5 7 , 2 6 7 . 1 1 1, 8 9 4 , 9 7 7 2,1 6 2 , 2 9 0 19 6 , 3 5 5 4.8 4 11 . 0 T O T A L P O W E R O P E R A T E D E Q U I P M E N T 30 , 2 5 6 , 4 9 0 . 3 8 21 , 1 4 4 , 9 2 3 9,1 1 1 , 5 6 7 76 6 , 1 7 2 2.5 3 CO M M U N I C A T I O N E Q U I P M E N T 39 7 . 0 0 C O M M U N I C A T I O N E Q U I P M E N T 15 - S Q 0 46 , 1 0 3 , 0 9 6 . 9 3 24 , 7 4 4 , 0 3 5 21 , 3 5 9 , 0 6 2 3,0 7 5 , 0 6 7 6.6 7 6. 9 39 7 . 5 0 S U B I N T E G R A T I O N 15 - S Q 0 3,5 3 7 , 8 2 5 . 3 7 65 5 , 9 8 4 2,8 8 1 , 8 4 1 23 5 , 9 1 4 6.6 7 12 . 2 39 7 . 6 0 D I S T R I B U T I O N 15 - S Q 0 56 3 , 9 6 4 . 4 8 41 , 3 8 7 52 2 , 5 7 7 37 , 6 1 6 6.6 7 13 . 9 T O T A L C O M M U N C A T I O N E Q U I P M E N T 50 , 2 0 4 , 8 8 6 . 7 8 25 , 4 4 1 , 4 0 6 24 , 7 6 3 , 4 8 0 3,3 4 8 , 5 9 7 6.6 7 39 8 . 0 0 MIS C E L L A N E O U S E Q U I P M E N T 10 - S Q 0 28 8 , 5 4 8 . 5 7 13 5 , 4 9 8 15 3 , 0 5 1 28 , 8 4 2 10 . 0 0 5.3 TO T A L G E N E R A L P L A N T 16 6 , 8 5 2 , 9 1 6 . 8 6 75 , 6 9 8 , 9 0 1 86 , 5 3 8 , 2 1 7 7,7 3 8 , 7 6 6 4.6 4 TO T A L D E P R E C I A B L E E L E C T R I C P L A N T 4,6 6 4 , 3 5 8 , 3 5 8 . 0 2 1,7 1 9 , 4 9 3 , 9 4 0 3,9 7 5 , 0 2 9 , 3 0 9 12 7 , 9 5 3 , 8 3 9 2.7 4 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VI-9 Attachment C J. Spanos, Avista Page 63 of 800 AV I S T A C O R P O R A T I O N TA B L E 1 . S U M M A R Y O F E S T I M A T E D S U R V I V O R C U R V E , N E T S A L V A G E P E R C E N T , O R I G I N A L C O S T , B O O K D E P R E C I A T I O N R E S E R V E A N D CA L C U L A T E D A N N U A L D E P R E C I A T I O N A C C R U A L S R E L A T E D T O E L E C T R I C , G A S A N D C O M M O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 PR O B A B L E NE T OR I G I N A L C O S T BO O K FU T U R E CA L C U L A T E D CO M P O S I T E RE T I R E M E N T SU R V I V I O R SA L V A G E AS O F DE P R E C I A T I O N BO O K AN N U A L A C C R U A L RE M A I N I N G DE P R E C I A B L E G R O U P DA T E CU R V E PE R C E N T DE C E M B E R 3 1 , 2 0 2 1 RE S E R V E AC C R U A L S AM O U N T RA T E LIF E (1 ) (2 ) (3 ) (4 ) (5 ) (6 ) (7 ) (8 ) (9 ) = ( 8 ) / ( 5 ) (1 0 ) = ( 7 ) / ( 8 ) GA S P L A N T - W A S H I N G T O N A N D I D A H O NA T U R A L G A S S T O R A G E A N D P R O C E S S I N G P L A N T 35 0 . 2 0 RIG H T S O F W A Y 65 - R 4 0 66 , 07 3 . 0 4 30 , 5 3 8 35 , 5 3 5 79 8 1.2 1 44 . 5 ST R U C T U R E S A N D I M P R O V E M E N T S 35 1 . 1 0 S T R U C T U R E S A N D I M P R O V E M E N T S 55 - R 2 . 5 (5 ) 1,9 3 4 , 6 7 2 . 0 5 61 7 , 8 5 6 1,4 1 3 , 5 5 0 31 , 0 4 5 1.6 0 45 . 5 35 1 . 2 0 C O M P R E S S O R S T A T I O N 55 - R 2 . 5 (5 ) 27 5 , 2 5 4 . 5 3 21 1 , 2 2 9 77 , 7 8 9 3, 2 3 4 1.1 7 24 . 1 35 1 . 3 0 M E A S U R I N G A N D R E G U L A T I N G S T A T I O N 55 - R 2 . 5 (5 ) 52 , 8 5 0 . 0 7 41 , 3 9 6 14 , 0 9 6 58 6 1.1 1 24 . 1 35 1 . 4 0 O F F I C E 55 - R 2 . 5 (5 ) 17 1 , 8 9 2 . 0 7 11 3 , 4 8 7 67 , 0 0 0 2, 2 7 6 1.3 2 29 . 4 T O T A L S T R U C T U R E S A N D I M P R O V E M E N T S 2,4 3 4 , 6 6 8 . 7 2 98 3 , 9 6 8 1,5 7 2 , 4 3 5 37 , 1 4 1 1.5 3 WE L L S 35 2 . 0 0 S T O R A G E W E L L S 60 - R 4 0 17 , 5 1 4 , 1 8 7 . 7 9 6, 3 9 2 , 5 3 4 11 , 1 2 1 , 6 5 4 25 7 , 4 6 5 1.4 7 43 . 2 35 2 . 2 0 R E S E R V O I R S 50 - R 4 0 20 3 , 3 3 0 . 4 7 10 0 , 0 4 0 10 3 , 2 9 0 3, 8 5 8 1.9 0 26 . 8 35 2 . 3 0 N O N - R E C O V E R A B L E G A S 50 - R 4 0 5,3 5 9 , 6 9 0 . 4 1 3, 8 8 0 , 4 5 0 1,4 7 9 , 2 4 0 45 , 7 8 8 0.8 5 32 . 3 T O T A L W E L L S 23 , 0 7 7 , 2 0 8 . 6 7 10 , 3 7 3 , 0 2 4 12 , 7 0 4 , 1 8 4 30 7 , 1 1 1 1.3 3 35 3 . 0 0 LIN E S 65 - R 4 0 2,0 5 9 , 7 7 6 . 7 7 65 8 , 3 4 9 1,4 0 1 , 4 2 8 30 , 9 1 2 1.5 0 45 . 3 35 4 . 0 0 CO M P R E S S O R S T A T I O N E Q U I P M E N T 55 - R 4 0 14 , 9 5 0 , 4 2 5 . 5 7 4, 0 9 5 , 1 2 2 10 , 8 5 5 , 3 0 4 26 5 , 3 4 7 1. 7 7 40 . 9 35 5 . 0 0 ME ASU R I N G A N D R E G U L A T I N G E Q U I P M E N T 35 - R 3 0 1,5 5 9 , 2 8 1 . 1 7 90 0 , 0 2 0 65 9 , 2 6 1 19 , 3 4 5 1.2 4 34 . 1 35 6 . 0 0 PU R I F I C A T I O N E Q U I P M E N T 35 - S 2 . 5 0 54 5 , 1 4 2 . 7 6 40 4 , 8 0 7 14 0 , 3 3 6 8, 5 9 3 1.5 8 16 . 3 35 7 . 0 0 OT H E R E Q U I P M E N T 45 - R 2 0 2,5 7 2 , 8 9 9 . 0 6 1, 0 4 0 , 3 0 0 1,5 3 2 , 5 9 9 44 , 3 1 6 1.7 2 34 . 6 TO T A L N A T U R A L G A S S T O R A G E A N D P R O C E S S I N G P L A N T 47 , 2 6 5 , 4 7 5 . 7 6 18 , 4 8 6 , 1 2 9 28 , 9 0 1 , 0 8 2 71 3 , 5 6 3 1.5 1 DIS T R I B U T I O N P L A N T 37 4 . 4 0 LA N D - E A S E M E N T S 60 - R 4 0 66 8 , 0 2 4 . 1 9 55 , 2 1 1 61 2 , 8 1 3 11 , 3 4 3 1.7 0 54 . 0 37 5 . 0 0 ST R U C T U R E S A N D I M P R O V E M E N T S 45 - R 2 0 1,5 7 5 , 5 8 8 . 8 1 29 1 , 3 2 4 1,2 8 4 , 2 6 5 37 , 1 9 3 2.3 6 34 . 5 37 6 . 0 0 MA I N S 55 - R 3 (2 0 ) 43 7 , 1 3 3 , 2 6 8 . 1 5 13 0 , 6 4 8 , 8 4 6 39 3 , 9 1 1 , 0 7 6 9,1 9 0 , 3 9 9 2.1 0 42 . 9 37 8 . 0 0 ME A S U R I N G A N D R E G U L A T I N G E Q U I P M E N T - G E N E R A L 32 - R 2 (1 5 ) 7,1 3 2 , 7 3 6 . 2 3 2, 3 2 6 , 3 4 9 5,8 7 6 , 2 9 8 28 7 , 5 0 3 4.0 3 20 . 4 37 9 . 0 0 ME A S U R I N G A N D R E G U L A T I N G E Q U I P M E N T - C I T Y G A T E 37 - S 0 . 5 (1 5 ) 6,6 0 2 , 6 7 8 . 3 4 2, 1 6 2 , 7 2 3 5,4 3 0 , 3 5 7 20 8 , 5 8 1 3.1 6 26 . 0 38 0 . 0 0 SE R V I C E S 52 - R 3 (2 5 ) 32 1 , 2 8 3 , 1 1 5 . 4 9 11 1 , 4 6 5 , 9 1 6 29 0 , 1 3 7 , 9 7 8 7,1 1 5 , 8 6 7 2.2 1 40 . 8 38 1 . 0 0 ME T E R S I D A H O 35 - R 1 (3 ) 31 , 9 3 7 , 7 2 2 . 1 4 10 , 7 1 5 , 0 7 5 22 , 1 8 0 , 7 7 9 88 1 , 3 9 7 2.7 6 25 . 2 W A S H I N G T O N 35 - R 1 (3 ) 52 , 7 4 1 , 9 8 4 . 8 7 10 , 1 6 5 , 0 3 0 44 , 1 5 9 , 2 1 4 1,6 3 6 , 4 9 8 3.1 0 27 . 0 W A S H I N G T O N A M I 15 - S 2 . 5 (3 ) 26 , 5 8 3 , 3 6 3 . 2 6 3, 7 6 8 , 6 3 3 23 , 6 1 2 , 2 3 1 1,9 8 6 , 2 4 0 7.4 7 11 . 9 T O T A L M E T E R S 11 1 , 2 6 3 , 0 7 0 . 2 7 24 , 6 4 8 , 7 3 8 89 , 9 5 2 , 2 2 4 4,5 0 4 , 1 3 5 4.0 5 38 5 . 0 0 IN D U S T R I A L M E A S U R I N G A N D R E G U L A T I N G S T A T I O N E Q U I P M E N T 65 - R 2 . 5 (1 5 ) 4,0 9 5 , 7 6 9 . 5 9 1, 6 3 7 , 4 5 2 3,0 7 2 , 6 8 3 59 , 5 4 8 1.4 5 51 . 6 TO T A L D I S T R I B U T I O N P L A N T 88 9 , 7 5 4 , 2 5 1 . 0 7 27 3 , 2 3 6 , 5 5 8 79 0 , 2 7 7 , 6 9 4 21 , 4 1 4 , 5 6 9 2.4 1 GE N E R A L P L A N T 38 9 . 4 2 LA N D E A S E M E N T S 50 - R 3 0 2,3 6 8 . 1 6 15 3 2,2 1 5 48 2.0 3 46 . 1 39 0 . 1 0 ST R U C T U R E S A N D I M P R O V E M E N T S - C O M P A N Y 30 - R 3 (5 ) 25 , 3 9 6 , 9 9 0 . 6 3 3, 0 2 6 , 9 5 9 23 , 6 3 9 , 8 8 1 89 9 , 9 4 1 3.5 4 26 . 3 39 1 . 1 0 OF F I C E F U R N I T U R E A N D E Q U I P M E N T - C O M P U T E R H A R D W A R E 5-S Q 0 14 3 , 3 1 9 . 8 4 68 , 0 8 0 75 , 2 4 0 28 , 6 6 8 20 . 0 0 2.6 TR A N S P O R T A T I O N E Q U I P M E N T 39 2 . 2 0 L I G H T T R U C K S 14 - L 2 . 5 10 6,0 9 6 , 6 6 6 . 6 7 3, 9 0 6 , 4 3 8 1,5 8 0 , 5 6 2 14 1 , 9 9 4 2.3 3 11 . 1 39 2 . 3 0 M E D I U M T R U C K S 17 - L 2 . 5 10 4,8 7 3 , 0 1 0 . 2 7 3, 0 4 2 , 0 4 0 1,3 4 3 , 6 6 9 99 , 5 2 2 2.0 4 13 . 5 39 2 . 4 0 H E A V Y T R U C K S 20 - R 4 10 3,0 9 8 , 0 3 8 . 4 0 1, 4 7 7 , 2 4 1 1,3 1 0 , 9 9 3 86 , 7 2 2 2.8 0 15 . 1 39 2 . 5 0 O T H E R 16 - L 2 10 1,6 8 0 , 1 0 3 . 2 2 76 4 , 8 3 3 74 7 , 2 6 0 68 , 6 0 0 4.0 8 10 . 9 T O T A L T R A N S P O R T A T I O N E Q U I P M E N T 15 , 7 4 7 , 8 1 8 . 5 6 9, 1 9 0 , 5 5 3 4,9 8 2 , 4 8 4 39 6 , 8 3 8 2.5 2 39 3 . 0 0 ST O R E S E Q U I P M E N T 25 - S Q 0 22 2 , 3 5 3 . 1 5 43 , 3 8 6 17 8 , 9 6 7 8, 8 9 5 4.0 0 20 . 1 39 4 . 0 0 TO O L S , S H O P A N D G A R A G E E Q U I P M E N T 20 - S Q 0 3,4 1 4 , 5 6 4 . 9 9 1, 4 0 8 , 3 4 0 2,0 0 6 , 2 2 5 17 0 , 6 1 3 5.0 0 11 . 8 39 5 . 0 0 LA B O R A T O R Y E Q U I P M E N T 15 - S Q 0 16 0 , 3 2 9 . 4 5 60 , 4 4 1 99 , 8 8 9 10 , 6 9 0 6.6 7 9.3 39 5 . 1 2 LA B O R A T O R Y E Q U I P M E N T - A M I 15 - S Q 0 40 , 8 4 0 . 5 8 9,5 1 0 31 , 3 3 1 2, 7 2 4 6.6 7 11 . 5 PO W E R O P E R A T E D E Q U I P M E N T 39 6 . 4 0 H EA V Y T R U C K S 24 - S 1 0 2,2 5 0 , 1 2 7 . 7 8 2, 0 7 8 , 2 1 3 17 1 , 9 1 5 11 , 5 8 4 0.5 1 14 . 8 39 6 . 5 0 O T H E R 16 - S 0 0 1,9 7 9 , 0 5 7 . 5 1 1, 3 2 1 , 5 2 7 65 7 , 5 3 1 57 , 7 5 3 2.92 11 . 4 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VI-10 Attachment C J. Spanos, Avista Page 64 of 800 AV I S T A C O R P O R A T I O N TA B L E 1 . S U M M A R Y O F E S T I M A T E D S U R V I V O R C U R V E , N E T S A L V A G E P E R C E N T , O R I G I N A L C O S T , B O O K D E P R E C I A T I O N R E S E R V E A N D CA L C U L A T E D A N N U A L D E P R E C I A T I O N A C C R U A L S R E L A T E D T O E L E C T R I C , G A S A N D C O M M O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 PR O B A B L E NE T OR I G I N A L C O S T BO O K FU T U R E CA L C U L A T E D CO M P O S I T E RE T I R E M E N T SU R V I V I O R SA L V A G E AS O F DE P R E C I A T I O N BO O K AN N U A L A C C R U A L RE M A I N I N G DE P R E C I A B L E G R O U P DA T E CU R V E PE R C E N T DE C E M B E R 3 1 , 2 0 2 1 RE S E R V E AC C R U A L S AM O U N T RA T E LIF E (1 ) (2 ) (3 ) (4 ) (5 ) (6 ) (7 ) (8 ) (9 ) = ( 8 ) / ( 5 ) (1 0 ) = ( 7 ) / ( 8 ) 39 7 . 0 0 CO M M U N I C A T I O N E Q U I P M E N T F U L L Y A C C R U E D FU L L Y A C C R U E D 29 . 1 2 29 0 0 - - A M O R T I Z E D 15 - S Q 0 88 4 , 1 1 5 . 4 5 40 0 , 8 5 0 48 3 , 2 6 5 59 , 0 0 1 6.6 7 8.2 TO T A L C O M M U N I C A T I O N E Q U I P M E N T 88 4 , 1 4 4 . 5 7 40 0 , 8 7 9 48 3 , 2 6 5 59 , 0 0 1 6.6 7 39 7 . 1 2 CO M M U N I C A T I O N E Q U I P M E N T - A M I 15 - S Q 0 19 , 9 4 2 . 4 7 4,6 4 9 15 , 2 9 3 1, 3 3 0 6.6 7 11 . 5 TO T A L G E N E R A L P L A N T 50 , 2 6 1 , 8 5 7 . 6 9 17 , 6 1 2 , 6 8 9 32 , 3 4 4 , 2 3 6 1,6 4 8 , 0 8 5 3.2 8 TO T A L G A S P L A N T - W A S H I N G T O N A N D I D A H O 98 7 , 2 8 1 , 5 8 4 . 5 2 30 9 , 3 3 5 , 3 7 6 85 1 , 5 2 3 , 0 1 2 23 , 7 7 6 , 2 1 7 2.4 1 GA S P L A N T - A L L O C A T E D A L L 39 1 . 1 0 OF F I C E F U R N I T U R E A N D E Q U I P M E N T - C O M P U T E R H A R D W A R E 5-S Q 0 33 3 , 3 4 1 . 2 5 19 5 , 6 2 5 13 7 , 7 1 6 66 , 6 5 5 20 . 0 0 2.1 TR A N S P O R T A T I O N E Q U I P M E N T 39 2 . 2 0 L I G H T T R U C K S 14 - L 2 . 5 10 50 , 2 3 7 . 3 8 5,6 8 7 39 , 5 2 7 3, 1 6 0 6.2 9 12 . 5 39 2 . 5 0 O T H E R 16 - L 2 10 46 , 9 5 0 . 2 0 6,8 9 3 35 , 3 6 2 2, 7 9 8 5.9 6 12 . 6 T O T A L T R A N S P O R T A T I O N E Q U I P M E N T 97 , 1 8 7 . 5 8 12 , 5 8 0 74 , 8 8 9 5, 9 5 8 6.1 3 39 4 . 0 0 TO O L S , S H O P A N D G A R A G E E Q U I P M E N T 20 - S Q 0 5,6 7 1 , 1 9 3 . 2 5 1, 7 4 3 , 6 8 7 3,9 2 7 , 5 0 6 28 3 , 4 5 6 5.0 0 13 . 9 39 5 . 0 0 LA B O R A T O R Y E Q U I P M E N T 15 - S Q 0 23 3 , 2 1 5 . 6 0 10 6 , 8 9 2 12 6 , 3 2 4 15 , 5 4 6 6.6 7 8.1 39 7 . 0 0 CO M M U N I C A T I O N E Q U I P M E N T 15 - S Q 0 28 2 , 9 1 9 . 8 5 12 3 , 1 5 0 15 9 , 7 7 0 18 , 8 6 9 6.6 7 8.5 TO T A L G A S P L A N T - A L L O C A T E D A L L 6,6 1 7 , 8 5 7 . 5 3 2, 1 8 1 , 9 3 4 4,4 2 6 , 2 0 5 39 0 , 4 8 4 5.9 0 GA S P L A N T - O R E G O N NA T U R A L G A S S T O R A G E A N D P R O C E S S I N G P L A N T 35 0 . 2 0 RIG H T S O F W A Y 65 - R 4 0 66 8 . 7 5 24 64 5 12 1.7 9 53 . 8 ST R U C T U R E S A N D I M P R O V E M E N T S 35 1 . 1 0 S T R U C T U R E S A N D I M P R O V E M E N T S 55 - R 2 . 5 (5 ) 24 , 1 7 2 . 3 6 74 0 24 , 6 4 1 53 4 2.2 1 46 . 1 35 1 . 2 0 C O M P R E S S O R S T A T I O N 55 - R 2 . 5 (5 ) 26 4 . 3 7 60 21 8 5 1.8 9 43 . 6 35 1 . 4 0 O F F I C E 55 - R 2 . 5 (5 ) 10 9 , 0 1 0 . 2 3 14 , 1 7 4 10 0 , 2 8 6 1, 8 9 2 1.7 4 53 . 0 T O T A L S T R U C T U R E S A N D I M P R O V E M E N T S 13 3 , 4 4 6 . 9 6 14 , 9 7 4 12 5 , 1 4 5 2, 4 3 1 1.8 2 WE L L S 35 2 . 0 0 S T O R A G E W E L L S 60 - R 4 0 1,4 2 9 , 9 5 7 . 6 9 22 5 , 3 6 5 1,2 0 4 , 5 9 3 24 , 8 0 1 1.7 3 48 . 6 35 2 . 2 0 R E S E R V O I R S 50 - R 4 0 1,4 6 4 , 1 6 1 . 5 4 28 9 , 1 6 4 1,1 7 4 , 9 9 8 29 , 7 8 6 2.0 3 39 . 4 35 2 . 3 0 N O N - R E C O V E R A B L E G A S 50 - R 4 0 45 0 , 6 2 0 . 1 5 11 9 , 5 5 3 33 1 , 0 6 7 8, 8 0 6 1.9 5 37 . 6 T O T A L W E L L S 3,3 4 4 , 7 3 9 . 3 8 63 4 , 0 8 1 2,7 1 0 , 6 5 8 63 , 3 9 3 1.9 0 35 3 . 0 0 LIN E S 65 - R 4 0 17 0 , 7 4 4 . 9 6 20 , 0 8 0 15 0 , 6 6 5 2, 7 8 7 1.6 3 54 . 1 35 4 . 0 0 CO M P R E S S O R S T A T I O N E Q U I P M E N T 55 - R 4 0 3,2 3 5 , 6 5 9 . 2 3 73 7 , 0 3 6 2, 4 9 8 , 6 2 4 59 , 0 6 8 1. 8 3 42 . 3 35 5 . 0 0 ME A S U R I N G A N D R E G U L A T I N G E Q U I P M E N T 35 - R 3 0 15 1 , 3 7 3 . 3 5 95 , 2 1 3 56 , 1 6 0 1,6 4 3 1. 0 9 34 . 2 35 6 . 0 0 PU R I F I C A T I O N E Q U I P M E N T 35 - S 2 . 5 0 15 , 1 0 5 . 7 0 54 3 14 , 5 6 2 56 9 3.77 25 . 6 35 7 . 0 0 OT H E R E Q U I P M E N T 45 - R 2 0 12 8 , 9 5 9 . 6 0 15 , 3 6 8 11 3 , 5 9 2 2, 6 9 6 2.0 9 42 . 1 TO T A L N A T U R A L G A S S T O R A G E A N D P R O C E S S I N G P L A N T 7,1 8 0 , 6 9 7 . 9 3 1, 5 1 7 , 3 1 9 5,6 7 0 , 0 5 1 13 2 , 5 9 9 1.8 5 DIS T R I B U T I O N P L A N T 37 4 . 4 0 LA N D - E A S E M E N T S 60 - R 4 0 60 9 , 8 3 0 . 4 1 74 , 6 0 3 53 5 , 2 2 8 10 , 1 7 4 1.6 7 52 . 6 37 5 . 0 0 ST R U C T U R E S A N D I M P R O V E M E N T S 45 - R 2 0 67 1 , 9 7 6 . 3 0 97 , 3 3 2 57 4 , 6 4 4 17 , 2 3 2 2.5 6 33 . 3 37 6 . 0 0 MA I N S 55 - R 3 (2 0 ) 26 9 , 9 1 7 , 3 8 7 . 9 3 78 , 2 0 5 , 5 7 7 24 5 , 6 9 5 , 2 8 9 5,6 9 3 , 7 9 4 2.1 1 43 . 2 37 8 . 0 0 ME A S U R I N G A N D R E G U L A T I N G E Q U I P M E N T - G E N E R A L 32 - R 2 (1 5 ) 6,1 1 7 , 0 3 6 . 8 5 1, 5 2 5 , 0 4 3 5,5 0 9 , 5 4 9 24 5 , 7 5 8 4.0 2 22 . 4 37 9 . 0 0 ME A S U R I N G A N D R E G U L A T I N G E Q U I P M E N T - C I T Y G A T E 37 - S 0 . 5 (1 5 ) 3,3 4 9 , 9 9 6 . 0 1 60 8 , 4 4 2 3,2 4 4 , 0 5 4 10 7 , 7 5 4 3.2 2 30 . 1 38 0 . 0 0 SE R V I C E S 52 - R 3 (2 5 ) 13 0 , 2 5 0 , 0 0 5 . 0 3 47 , 5 2 8 , 3 0 4 11 5 , 2 8 4 , 2 0 2 2,7 9 6 , 1 9 4 2.1 5 41 . 2 38 1 . 0 0 ME T E R S 35 - R 1 (3 ) 55 , 8 3 4 , 0 7 0 . 6 5 9, 0 5 3 , 0 0 2 48 , 4 5 6 , 0 9 1 1,8 6 4 , 5 1 8 3.3 4 26 . 0 38 5 . 0 0 IN D U S T R I A L M E A S U R I N G A N D R E G U L A T I N G S T A T I O N E Q U I P M E N T 65 - R 2 . 5 (1 5 ) 2,4 7 6 , 5 4 7 . 9 4 87 1 , 7 5 3 1,9 7 6 , 2 7 7 35 , 6 7 8 1.4 4 55 . 4 38 7 . 0 0 OT H E R E Q U I P M E N T 18 - S Q 0 53 9 . 2 9 53 9 0 0 - - TO T A L D I S T R I B U T I O N P L A N T 46 9 , 2 2 7 , 3 9 0 . 4 1 13 7 , 9 6 4 , 5 9 5 42 1 , 2 7 5 , 3 3 4 10 , 7 7 1 , 1 0 2 2.3 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VI-11 Attachment C J. Spanos, Avista Page 65 of 800 AV I S T A C O R P O R A T I O N TA B L E 1 . S U M M A R Y O F E S T I M A T E D S U R V I V O R C U R V E , N E T S A L V A G E P E R C E N T , O R I G I N A L C O S T , B O O K D E P R E C I A T I O N R E S E R V E A N D CA L C U L A T E D A N N U A L D E P R E C I A T I O N A C C R U A L S R E L A T E D T O E L E C T R I C , G A S A N D C O M M O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 PR O B A B L E NE T OR I G I N A L C O S T BO O K FU T U R E CA L C U L A T E D CO M P O S I T E RE T I R E M E N T SU R V I V I O R SA L V A G E AS O F DE P R E C I A T I O N BO O K AN N U A L A C C R U A L RE M A I N I N G DE P R E C I A B L E G R O U P DA T E CU R V E PE R C E N T DE C E M B E R 3 1 , 2 0 2 1 RE S E R V E AC C R U A L S AM O U N T RA T E LIF E (1 ) (2 ) (3 ) (4 ) (5 ) (6 ) (7 ) (8 ) (9 ) = ( 8 ) / ( 5 ) (1 0 ) = ( 7 ) / ( 8 ) GE N E R A L P L A N T 39 0 . 1 0 ST R U C T U R E S A N D I M P R O V E M E N T S - C O M P A N Y 30 - R 3 (5 ) 4,1 1 1 , 0 7 3 . 8 5 1, 9 3 7 , 6 0 1 2,3 7 9 , 0 2 6 13 8 , 4 7 9 3.3 7 17 . 2 39 1 . 1 0 OF F I C E F U R N I T U R E A N D E Q U I P M E N T - C O M P U T E R H A R D W A R E 5-S Q 0 12 , 2 2 2 . 5 1 6,1 1 1 6,1 1 2 2, 4 4 5 20 . 0 0 2.5 TR A N S P O R T A T I O N E Q U I P M E N T 39 2 . 2 0 L I G H T T R U C K S 14 - L 2 . 5 10 3,2 8 5 , 7 7 1 . 2 0 1, 2 7 1 , 0 0 0 1,6 8 6 , 1 9 4 18 0 , 8 5 4 5.5 0 9.3 39 2 . 3 0 M E D I U M T R U C K S 17 - L 2 . 5 10 1,1 8 1 , 3 3 5 . 7 3 64 2 , 5 4 4 42 0 , 6 5 9 34 , 2 0 1 2.9 0 12 . 3 39 2 . 5 0 O T H E R 16 - L 2 10 23 0 , 6 5 3 . 0 0 41 , 7 3 9 16 5 , 8 4 9 13 , 5 0 0 5.8 5 12 . 3 T O T A L T R A N S P O R T A T I O N E Q U I P M E N T 4,6 9 7 , 7 5 9 . 9 3 1, 9 5 5 , 2 8 3 2,2 7 2 , 7 0 2 22 8 , 5 5 5 4.8 7 39 3 . 0 0 ST O R E S E Q U I P M E N T 25 - S Q 0 20 , 7 9 1 . 8 2 17 , 0 1 0 3,7 8 2 83 1 4.0 0 4.6 39 4 . 0 0 TO O L S , S H O P A N D G A R A G E E Q U I P M E N T 20 - S Q 0 96 2 , 7 7 2 . 0 4 51 2 , 5 0 5 45 0 , 2 6 7 48 , 1 0 5 5.0 0 9.4 39 5 . 0 0 LA B O R A T O R Y E Q U I P M E N T 15 - S Q 0 18 , 5 8 6 . 3 1 3,1 0 4 15 , 4 8 3 1, 2 3 9 6.6 7 12 . 5 39 6 . 5 0 PO W E R O P E R A T E D E Q U I P M E N T - O T H E R 16 - S 0 0 43 , 8 3 3 . 9 5 44 , 3 7 8 (5 4 4 ) 0 - - 39 7 . 0 0 CO M M U N I C A T I O N E Q U I P M E N T 15 - S Q 0 76 6 , 3 9 6 . 8 9 41 7 , 9 9 5 34 8 , 4 0 2 51 , 0 9 0 6.6 7 6.8 39 8 . 0 0 MIS C E L L A N E O U S E Q U I P M E N T F U L L Y A C C R U E D FU L L Y A C C R U E D 2,3 6 7 . 1 6 2,3 6 7 0 0 - - A M O R T I Z E D 10 - S Q 0 6,7 3 2 . 60 33 8 6,39 5 67 3 10 . 0 0 9.5 TO T A L M I S C E L L A N E O U S E Q U I P M E N T 9,0 9 9 . 7 6 2,7 0 5 6,3 9 5 67 3 7.4 0 TO T A L G E N E R A L P L A N T 10 , 6 4 2 , 5 3 7 . 0 6 4, 8 9 6 , 6 9 2 5,4 8 1 , 6 2 5 47 1 , 4 1 7 4.4 3 TO T A L G A S P L A N T - O R E G O N 48 7 , 0 5 0 , 6 2 5 . 4 0 14 4 , 3 7 8 , 6 0 5 43 2 , 4 2 7 , 0 1 0 11 , 3 7 5 , 1 1 8 2.3 4 TO T A L D E P R E C I A B L E G A S P L A N T 1,4 8 0 , 9 5 0 , 0 6 7 . 4 5 45 5 , 8 9 5 , 9 1 5 1,2 8 8 , 3 7 6 , 2 2 7 35 , 5 4 1 , 8 1 9 2.4 0 CO M M O N P L A N T 38 9 . 3 0 R E M O V I N G P R O P E R T Y O F O T H E R S 65 - R 4 0 3,6 2 3 , 3 3 2 . 0 0 26 9 , 4 2 3 3,3 5 3 , 9 0 9 60 , 3 4 2 1.6 7 55 . 6 38 9 . 4 0 L A N D E A S E M E N T S 65 - R 4 0 13 9 , 1 1 5 . 1 6 38 , 1 8 8 10 0 , 9 2 8 1, 7 5 2 1.2 6 57 . 6 T O T A L L A N D A N D L A N D R I G H T S 3,7 6 2 , 4 4 7 . 1 6 30 7 , 6 1 0 3,4 5 4 , 8 3 7 62 , 0 9 4 1.6 5 39 0 . 1 0 ST R U C T U R E S A N D I M P R O V E M E N T S - C O M P A N Y 50 - R 2 (1 0 ) 15 9 , 3 2 4 , 4 8 5 . 8 1 14 , 8 8 1 , 3 6 3 16 0 , 3 7 5 , 5 7 1 3,9 0 7 , 3 1 7 2.4 5 41 . 0 OF F I C E F U R N I T U R E A N D E Q U I P M E N T 39 1 . 0 0 O F F I C E F U R N I T U R E A N D E Q U I P M E N T 15 - S Q 0 18 , 5 7 5 , 1 5 4 . 0 4 8, 2 0 0 , 0 4 1 10 , 3 7 5 , 1 1 3 1,2 3 8 , 3 7 5 6.6 7 8. 4 39 1 . 1 0 C O M P U T E R H A R D W A R E F U L L Y A C C R U E D FU L L Y A C C R U E D 49 1 , 3 7 0 . 7 7 49 1 , 3 7 1 0 0 - - A M O R T I Z E D 5-S Q 0 60 , 9 3 8 , 4 6 3 . 2 3 31 , 9 8 0 , 0 0 0 28 , 9 5 8 , 4 6 3 12 , 1 8 8 , 3 3 5 20 . 0 0 2.4 T O T A L C O M P U T E R H A R D W A R E 61 , 4 2 9 , 8 3 4 . 0 0 32 , 4 7 1 , 3 7 1 28 , 9 5 8 , 4 6 3 12 , 1 8 8 , 3 3 5 19 . 8 4 39 1 . 1 2 C O M P U T E R H A R D W A R E - A M I 5-S Q 0 4,9 6 3 , 5 9 8 . 7 4 3, 3 6 6 , 8 4 2 1,5 9 6 , 7 5 7 99 2 , 7 2 0 20 . 0 0 1.6 39 1 . 1 3 C O M P U T E R H A R D W A R E - M D M 5-S Q 0 2,63 7 , 3 4 8 . 6 3 2, 1 1 0 , 0 0 0 52 7 , 3 4 9 52 7 , 3 4 9 20 . 0 0 1. 0 T O T A L O F F I C E F U R N I T U R E A N D E Q U I P M E N T 87 , 6 0 5 , 9 3 5 . 4 1 46 , 1 4 8 , 2 5 4 41 , 4 5 7 , 6 8 2 14 , 9 4 6 , 7 7 9 17 . 0 6 TR A N S P O R T A T I O N E Q U I P M E N T 39 2 . 1 0 A U T O S 11 - S 2 . 5 10 84 , 7 3 9 . 9 1 12 4 , 9 5 7 (4 8 , 6 9 1 ) 0 - - 39 2 . 2 0 L I G H T T R U C K S 14 - L 2 . 5 10 4,5 9 1 , 0 5 1 . 2 5 3, 1 7 4 , 9 6 6 95 6 , 9 8 0 85 , 6 2 7 1.8 7 11 . 2 39 2 . 30 M E D I U M T R U C K S 17 - L 2 . 5 10 1,5 8 0 , 5 8 0 . 4 0 1, 0 6 8 , 4 6 1 35 4 , 0 6 1 25 , 5 3 7 1.6 2 13 . 9 39 2 . 4 0 H E A V Y T R U C K S 20 - R 4 10 42 6 , 3 6 6 . 2 9 25 , 1 7 7 35 8 , 5 5 2 25 , 5 8 4 6.0 0 14 . 0 39 2 . 5 0 O T H E R 16 - L 2 10 1,1 1 5 , 8 5 1 . 0 5 67 9 , 0 4 7 32 5 , 2 1 9 25 , 4 1 5 2.2 8 12 . 8 39 2 . 6 0 A I R P L A N E 12 - S 1 . 5 30 6,5 6 6 , 8 0 5 . 8 1 3, 8 2 4 , 3 7 0 77 2 , 3 9 4 89 , 0 8 8 1.3 6 8.7 T O T A L T R A N S P O R T A T I O N E Q U I P M E N T 14 , 3 6 5 , 3 9 4 . 7 1 8, 8 9 6 , 9 7 9 2,7 1 8 , 5 1 5 25 1 , 2 5 1 1.7 5 39 3 . 0 0 ST O R E S E Q U I P M E N T 25 - S Q 0 5,3 4 2 , 3 8 7 . 5 0 1, 4 7 2 , 1 9 6 3,8 7 0 , 1 9 2 21 3 , 6 4 8 4.0 0 18 . 1 39 4 . 0 0 TO O L S , S H O P A N D G A R A G E E Q U I P M E N T 20 - S Q 0 16 , 8 8 9 , 1 6 3 . 4 4 6, 4 9 1 , 7 4 7 10 , 3 9 7 , 4 1 7 84 4 , 2 0 3 5.0 0 12 . 3 39 5 . 0 0 LA B O R A T O R Y E Q U I P M E N T 15 - S Q 0 1,5 0 7 , 7 9 0 . 9 4 48 9 , 5 8 9 1,0 1 8 , 2 0 2 10 0 , 5 0 3 6.6 7 10 . 1 PO W E R O P E R A T E D E Q U I P M E N T 39 6 . 3 0 M E D I U M T R U C K S 16 - L 2 0 59 , 5 0 1 . 8 9 59 , 5 0 2 0 0 - - 39 6 . 5 0 O T H E R 16 - S 0 0 1,9 3 0 , 6 8 6 . 5 5 1, 3 7 1 , 8 4 5 55 8 , 8 4 2 62 , 5 7 7 3.2 4 8. 9 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VI-12 Attachment C J. Spanos, Avista Page 66 of 800 AV I S T A C O R P O R A T I O N TA B L E 1 . S U M M A R Y O F E S T I M A T E D S U R V I V O R C U R V E , N E T S A L V A G E P E R C E N T , O R I G I N A L C O S T , B O O K D E P R E C I A T I O N R E S E R V E A N D CA L C U L A T E D A N N U A L D E P R E C I A T I O N A C C R U A L S R E L A T E D T O E L E C T R I C , G A S A N D C O M M O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 PR O B A B L E NE T OR I G I N A L C O S T BO O K FU T U R E CA L C U L A T E D CO M P O S I T E RE T I R E M E N T SU R V I V I O R SA L V A G E AS O F DE P R E C I A T I O N BO O K AN N U A L A C C R U A L RE M A I N I N G DE P R E C I A B L E G R O U P DA T E CU R V E PE R C E N T DE C E M B E R 3 1 , 2 0 2 1 RE S E R V E AC C R U A L S AM O U N T RA T E LIF E (1 ) (2 ) (3 ) (4 ) (5 ) (6 ) (7 ) (8 ) (9 ) = ( 8 ) / ( 5 ) (1 0 ) = ( 7 ) / ( 8 ) CO M M U N I C A T I O N E Q U I P M E N T 39 7 . 0 0 C O M M U N I C A T I O N E Q U I P M E N T 15 - S Q 0 93 , 4 0 4 , 8 7 2 . 2 1 31 , 9 3 6 , 1 5 0 61 , 4 6 8 , 7 2 2 6,2 2 8 , 3 8 1 6.6 7 9.9 39 7 . 1 2 A M I 15 - S Q 0 7,5 3 0 , 5 1 2 . 1 0 1, 6 3 1 , 2 3 4 5,8 9 9 , 2 7 8 50 2 , 3 9 2 6.6 7 11 . 7 39 7 . 2 0 P O R T A B L E 10 - S Q 0 3,5 1 6 , 9 2 3 . 1 0 2, 1 9 9 , 4 2 1 1,3 1 7 , 5 0 2 35 1 , 5 6 0 10 . 0 0 3.7 T O T A L C O M M U N I C A T I O N E Q U I P M E N T 10 4 , 4 5 2 , 3 0 7 . 4 1 35 , 7 6 6 , 8 0 6 68 , 6 8 5 , 5 0 2 7,0 8 2 , 3 3 3 6.7 8 39 8 . 0 0 MIS C E L L A N E O U S E Q U I P M E N T 10 - S Q 0 70 7 , 3 8 1 . 7 8 40 2 , 2 5 0 30 5 , 1 3 2 70 , 7 4 4 10 . 0 0 4.3 TO T A L D E P R E C I A B L E C O M M O N P L A N T 39 5 , 9 4 7 , 4 8 2 . 6 0 11 6 , 2 8 8 , 1 4 0 29 2 , 8 4 1 , 8 9 2 27 , 5 4 1 , 4 4 9 6.9 6 RE S E R V E A D J U S T M E N T F O R A M O R T I Z A T I O N - E L E C T R I C P L A N T 39 1 . 0 0 OF F I C E F U R N I T U R E A N D E Q U I P M E N T (1 2 0 ) 24 ** 39 1 . 1 0 OF F I C E F U R N I T U R E A N D E Q U I P M E N T - C O M P U T E R H A R D W A R E 22 2 , 2 5 5 (4 4 , 4 5 1 ) ** 39 1 . 1 2 OF F I C E F U R N I T U R E A N D E Q U I P M E N T - C O M P U T E R H A R D W A R E (5 4 , 6 4 9 ) 10 , 9 3 0 ** 39 3 . 0 0 ST O R E S E Q U I P M E N T (3 3 , 2 9 8 ) 6, 6 6 0 ** 39 4 . 0 0 TO O L S , S H O P A N D G A R A G E E Q U I P M E N T (1 1 7 , 0 0 0 ) 23 , 4 0 0 ** 39 5 . 0 0 LA B O R A T O R Y E Q U I P M E N T 28 6 , 4 0 0 (5 7 , 2 8 0 ) ** 39 5 . 1 2 LA B O R A T O R Y E Q U I P M E N T - A M I 40 , 1 0 0 (8 , 0 2 0 ) ** 39 7 . 0 0 CO M M U N I C A T I O N E Q U I P M E N T (1 , 6 1 0 , 0 0 0 ) 32 2 , 0 0 0 ** 39 7 . 5 0 CO M M U N I C A T I O N E Q U I P M E N T - S U B I N T E G R A T I O N (2 8 4 , 0 0 0 ) 56 , 8 0 0 ** 39 7 . 6 0 CO M M U N I C A T I O N E Q U I P M E N T - D I S T R I B U T I O N (8 , 4 5 2 ) 1, 6 9 0 ** 39 8 . 0 0 MIS C E L L A N E O U S E Q U I P M E N T 4,8 6 5 (9 7 3 ) ** TO T A L R E S E R V E F O R A M O R T I Z A T I O N - E L E C T R I C P L A N T (1 , 5 5 3 , 8 9 9 ) 31 0 , 7 8 0 RE S E R V E A D J U S T M E N T F O R A M O R T I Z A T I O N - G A S P L A N T - W A S H I N G T O N A N D I D A H O 39 1 . 1 0 OF F I C E F U R N I T U R E A N D E Q U I P M E N T - C O M P U T E R H A R D W A R E 16 1 , 4 9 2 (3 2 , 2 9 8 ) ** 39 3 . 0 0 ST O R E S E Q U I P M E N T (3 , 2 5 0 ) 65 0 ** 39 4 . 0 0 TO O L S , S H O P A N D G A R A G E E Q U I P M E N T (6 7 , 4 0 0 ) 13 , 4 8 0 ** 39 5 . 0 0 LA B O R A T O R Y E Q U I P M E N T 19 , 5 6 8 (3 , 9 1 4 ) ** 39 5 . 1 2 LA B O R A T O R Y E Q U I P M E N T - A M I (3 2 0 ) 64 ** 39 7 . 0 0 CO M M U N I C A T I O N E Q U I P M E N T (9 8 , 0 1 5 ) 19 , 6 0 3 ** 39 7 . 1 2 CO M M U N I C A T I O N E Q U I P M E N T - A M I (7 3 0 ) 14 6 ** TO T A L R E S E R V E F O R A M O R T I Z A T I O N - G A S P L A N T - W A S H I N G T O N A N D I D A H O 11 , 3 4 5 (2 , 2 6 9 ) RE S E R V E A D J U S T M E N T F O R A M O R T I Z A T I O N - G A S P L A N T - A L L O C A T E D A L L 39 1 . 1 0 OF F I C E F U R N I T U R E A N D E Q U I P M E N T - C O M P U T E R H A R D W A R E (2 3 , 8 7 2 ) 4, 7 7 4 ** 39 4 . 0 0 TO O L S , S H O P A N D G A R A G E E Q U I P M E N T 16 3 , 4 0 0 (3 2 , 6 8 0 ) ** 39 5 . 0 0 LA B O R A T O R Y E Q U I P M E N T 1,4 5 0 (2 9 0 ) ** 39 7 . 0 0 CO M M U N I C A T I O N E Q U I P M E N T (2 2 , 8 7 0 ) 4, 5 7 4 ** TO T A L R E S E R V E F O R A M O R T I Z A T I O N - G A S P L A N T - A L L O C A T E D A L L 11 8 , 1 0 8 (2 3 , 6 2 2 ) RE S E R V E A D J U S T M E N T F O R A M O R T I Z A T I O N - G A S P L A N T - O R E G O N 39 1 . 1 0 OF F I C E F U R N I T U R E A N D E Q U I P M E N T - C O M P U T E R H A R D W A R E (3 9 ) 8 ** 39 3 . 0 0 ST O R E S E Q U I P M E N T (2 , 5 4 0 ) 50 8 ** 39 4 . 0 0 TO O L S , S H O P A N D G A R A G E E Q U I P M E N T 13 6 , 7 6 1 (2 7 , 3 5 2 ) ** 39 5 . 0 0 LA B O R A T O R Y E Q U I P M E N T (3 9 ) 8 ** 39 7 . 0 0 CO M M U N I C A T I O N E Q U I P M E N T 27 4 , 5 9 7 (5 4 , 9 1 9 ) ** 39 8 . 0 0 MI S C E L L A N E O U S E Q U I P M E N T (8 2 5 ) 16 5 ** TO T A L R E S E R V E F O R A M O R T I Z A T I O N - G A S P L A N T - O R E G O N 40 7 , 9 1 5 (8 1 , 5 8 2 ) _____________________________________________________________________________________________ Avista Corporation December 31, 2021VI-13 Attachment C J. Spanos, Avista Page 67 of 800 AV I S T A C O R P O R A T I O N TA B L E 1 . S U M M A R Y O F E S T I M A T E D S U R V I V O R C U R V E , N E T S A L V A G E P E R C E N T , O R I G I N A L C O S T , B O O K D E P R E C I A T I O N R E S E R V E A N D CA L C U L A T E D A N N U A L D E P R E C I A T I O N A C C R U A L S R E L A T E D T O E L E C T R I C , G A S A N D C O M M O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 PR O B A B L E NE T OR I G I N A L C O S T BO O K FU T U R E CA L C U L A T E D CO M P O S I T E RE T I R E M E N T SU R V I V I O R SA L V A G E AS O F DE P R E C I A T I O N BO O K AN N U A L A C C R U A L RE M A I N I N G DE P R E C I A B L E G R O U P DA T E CU R V E PE R C E N T DE C E M B E R 3 1 , 2 0 2 1 RE S E R V E AC C R U A L S AM O U N T RA T E LIF E (1 ) (2 ) (3 ) (4 ) (5 ) (6 ) (7 ) (8 ) (9 ) = ( 8 ) / ( 5 ) (1 0 ) = ( 7 ) / ( 8 ) RE S E R V E A D J U S T M E N T F O R A M O R T I Z A T I O N - C O M M O N P L A N T 39 1 . 0 0 OF F I C E F U R N I T U R E A N D E Q U I P M E N T - O F F I C E F U R N I T U R E A N D E Q U I P M E N T 4,2 9 0 , 0 0 0 (8 5 8 , 0 0 0 ) ** 39 1 . 1 0 OF F I C E F U R N I T U R E A N D E Q U I P M E N T - C O M P U T E R H A R D W A R E 9,4 6 1 , 0 2 7 (1 , 8 9 2 , 2 0 5 ) ** 39 1 . 1 2 OF F I C E F U R N I T U R E A N D E Q U I P M E N T - C O M P U T E R H A R D W A R E - A M I (2 4 9 , 1 6 6 ) 49 , 8 3 3 ** 39 1 . 1 3 OF F I C E F U R N I T U R E A N D E Q U I P M E N T - C O M P U T E R H A R D W A R E - M D M 34 6 , 1 2 9 (6 9 , 2 2 6 ) ** 39 3 . 0 0 ST O R E S E Q U I P M E N T 13 4 , 0 0 0 (2 6 , 8 0 0 ) ** 39 4 . 0 0 TO O L S , S H O P A N D G A R A G E E Q U I P M E N T 13 7 , 0 0 0 (2 7 , 4 0 0 ) ** 39 5 . 0 0 LA B O R A T O R Y E Q U I P M E N T 23 6 , 5 0 0 (4 7 , 3 0 0 ) ** 39 7 . 0 0 CO M M U N I C A T I O N E Q U I P M E N T (8 , 5 0 0 , 0 0 0 ) 1, 7 0 0 , 0 0 0 ** 39 7 . 1 2 CO M M U N I C A T I O N E Q U I P M E N T - A M I (4 3 8 , 7 8 9 ) 87 , 7 5 8 ** 39 7 . 2 0 CO M M U N I C A T I O N E Q U I P M E N T - P O R T A B L E 1,5 1 1 , 6 5 0 (3 0 2 , 3 3 0 ) ** 39 8 . 0 0 MIS C E L L A N E O U S E Q U I P M E N T 30 1 , 4 4 2 (6 0 , 2 8 8 ) ** TO T A L R E S E R V E F O R A M O R T I Z A T I O N - C O M M O N P L A N T 7,2 2 9 , 7 9 3 (1 , 4 4 5 , 9 5 8 ) TO T A L D E P R E C I A B L E E L E C T R I C , G A S A N D C O M M O N P L A N T 6,5 4 1 , 2 5 5 , 9 0 8 . 0 7 2,2 9 7 , 8 9 1 , 2 5 8 5,5 5 6 , 2 4 7 , 4 2 8 18 9 , 7 9 4 , 4 5 6 2. 9 0 AM O R T I Z A B L E A N D L A N D - E L E C T R I C P L A N T 30 2 . 0 0 FR A N C H I S E S A N D C O N S E N T S 46 , 7 4 9 , 0 5 3 . 9 8 15 , 1 3 7 , 4 1 1 30 3 . 0 0 MIS C E L L A N E O U S I N T A N G I B L E P L A N T 7,4 9 4 , 3 8 3 . 9 2 2,0 0 4 , 3 1 5 30 3 . 1 0 MIS C E L L A N E O U S I N T A N G I B L E P L A N T - S O F T W A R E - 5 Y E A R L I F E 26 , 5 4 7 , 5 9 3 . 9 6 12 , 5 5 3 , 0 3 4 30 3 . 1 3 MIS C E L L A N E O U S I N T A N G I B L E P L A N T - S A A S - 5 Y E A R L I F E 1,7 6 8 , 9 2 0 . 1 2 18 9 , 1 1 5 30 3 . 3 5 MIS C E L L A N E O U S I N T A N G I B L E P L A N T - S P O K A N E R I V E R 4,4 7 0 , 3 5 5 . 8 2 64 2 , 3 6 5 31 0 . 2 0 LA N D 3,4 3 0 , 2 9 7 . 1 9 31 7 . 0 0 AR O 15 , 5 3 6 , 2 5 2 . 1 0 2,7 8 7 , 8 0 6 33 0 . 2 0 LA N D 6,9 8 0 , 5 9 9 . 5 6 33 0 . 2 1 LA N D - C O N S E R V A T I O N - H A B I T A T 5,9 8 9 , 3 7 6 . 7 9 33 0 . 2 2 LA N D 1,3 2 8 , 8 7 3 . 6 4 (7 9 , 2 4 0 ) 33 0 . 2 5 LA N D - C O N S E R V A T I O N - F I S H E R I E S 4,1 1 3 , 0 3 1 . 4 9 33 0 . 4 5 LA N D 17 5 , 9 8 1 . 2 2 34 0 . 2 0 LA N D 90 5 , 1 6 7 . 6 7 34 7 . 0 0 AR O 35 1 , 6 8 1 . 6 2 10 4 , 1 0 6 35 0 . 2 0 RIG H T S O F W A Y 7,2 0 8 , 6 0 0 . 5 9 36 0 . 1 1 LA N D H E L D F O R F U T U R E U S E 9,5 4 4 , 4 3 3 . 5 6 36 0 . 2 0 LA N D 8,9 4 5 , 3 0 1 . 2 1 36 0 . 5 0 LA N D - E A S E M E N T S 36 7 , 8 5 0 . 0 0 37 0 . 3 0 ME T E R S - W A S H I N G T O N S T A N D A R D - R E S E R V E A D J U S T M E N T (2 0 , 3 6 9 , 2 9 8 ) 38 9 . 2 0 LA N D 88 5 , 6 6 5 . 1 0 39 0 . 2 0 ST R U C T U R E S A N D I M P R O V E M E N T S - L E A S E H O L D 2,3 5 9 , 3 8 8 . 7 0 74 7 , 5 6 3 TO T A L A M O R T I Z A B L E A N D L A N D - E L E C T R I C P L A N T 15 5 , 1 5 2 , 8 0 8 . 2 4 13 , 7 1 7 , 1 7 6 AM O R T I Z A B L E A N D L A N D - G A S P L A N T - W A S H I N G T O N A N D I D A H O 30 3 . 0 0 MIS C E L L A N E O U S I N T A N G I B L E P L A N T 1,7 9 4 , 1 1 1 . 2 9 43 6 , 8 9 4 35 0 . 1 0 LA N D 41 3 , 2 4 0 . 4 0 37 4 . 2 0 LA N D 88 , 5 9 4 . 7 0 38 1 . 0 0 ME T E R S - W A S H I N G T O N - R E S E R V E A D J U S T M E N T (4 , 1 0 7 , 0 8 7 ) 38 9 . 2 0 LA N D 3,0 7 1 , 0 1 6 . 6 5 TO T A L A M O R T I Z A B L E A N D L A N D - G A S P L A N T - W A S H I N G T O N A N D I D A H O 5,3 6 6 , 9 6 3 . 0 4 (3 , 6 7 0 , 1 9 3 ) AM O R T I Z A B L E A N D L A N D - G A S P L A N T - A L L O C A T E D A L L 30 3 . 1 0 MIS C E L L A N E O U S I N T A N G I B L E P L A N T - S O F T W A R E - 5 Y E A R L I F E 45 0 , 1 9 4 . 4 9 17 7 , 5 0 9 35 0 . 1 0 LA N D 89 9 , 4 8 9 . 9 4 TO T A L A M O R T I Z A B L E A N D L A N D - G A S P L A N T - A L L O C A T E D A L L 1,3 4 9 , 6 8 4 . 4 3 17 7 , 5 0 9 AM O R T I Z A B L E A N D L A N D - G A S P L A N T - O R E G O N 30 3 . 0 0 MIS C E L L A N E O U S I N T A N G I B L E P L A N T 42 5 , 9 5 0 . 6 2 12 0 , 9 6 0 30 4 . 0 0 LA N D 59 , 9 2 3 . 8 7 35 0 . 1 0 LA N D 78 4 . 4 9 37 4 . 2 0 LA N D 21 7 , 8 1 7 . 9 4 38 9 . 2 0 LA N D 84 5 , 5 1 6 . 9 1 TO T A L A M O R T I Z A B L E A N D L A N D - G A S P L A N T - O R E G O N 1,5 4 9 , 9 9 3 . 8 3 12 0 , 9 6 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VI-14 Attachment C J. Spanos, Avista Page 68 of 800 AV I S T A C O R P O R A T I O N TA B L E 1 . S U M M A R Y O F E S T I M A T E D S U R V I V O R C U R V E , N E T S A L V A G E P E R C E N T , O R I G I N A L C O S T , B O O K D E P R E C I A T I O N R E S E R V E A N D CA L C U L A T E D A N N U A L D E P R E C I A T I O N A C C R U A L S R E L A T E D T O E L E C T R I C , G A S A N D C O M M O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 PR O B A B L E NE T OR I G I N A L C O S T BO O K FU T U R E CA L C U L A T E D CO M P O S I T E RE T I R E M E N T SU R V I V I O R SA L V A G E AS O F DE P R E C I A T I O N BO O K AN N U A L A C C R U A L RE M A I N I N G DE P R E C I A B L E G R O U P DA T E CU R V E PE R C E N T DE C E M B E R 3 1 , 2 0 2 1 RE S E R V E AC C R U A L S AM O U N T RA T E LIF E (1 ) (2 ) (3 ) (4 ) (5 ) (6 ) (7 ) (8 ) (9 ) = ( 8 ) / ( 5 ) (1 0 ) = ( 7 ) / ( 8 ) AM O R T I Z A B L E A N D L A N D - C O M M O N P L A N T 30 3 . 0 0 MIS C E L L A N E O U S I N T A N G I B L E P L A N T 6,4 1 6 , 5 5 0 . 7 9 4,7 5 9 , 8 3 2 30 3 . 1 0 MIS C E L L A N E O U S I N T A N G I B L E P L A N T - S O F T W A R E - 2 Y E A R L I F E 32 1 , 9 5 0 . 4 7 57 , 0 0 6 30 3 . 1 0 MIS C E L L A N E O U S I N T A N G I B L E P L A N T - S O F T W A R E - 3 Y E A R L I F E 7,4 2 9 , 9 2 3 . 5 9 57 6 , 6 0 1 30 3 . 1 0 MIS C E L L A N E O U S I N T A N G I B L E P L A N T - S O F T W A R E - 5 Y E A R L I F E 17 4 , 4 3 5 , 1 5 8 . 1 4 94 , 9 9 8 , 7 3 4 30 3 . 1 1 MIS C E L L A N E O U S I N T A N G I B L E P L A N T - S O F T W A R E - 1 5 Y E A R L I F E ( C O M P A S S ) 10 0 , 8 3 1 , 2 0 3 . 2 2 47 , 5 0 2 , 9 4 0 30 3 . 1 2 MIS C E L L A N E O U S I N T A N G I B L E P L A N T - S O F T W A R E - 1 2 . 5 Y E A R L I F E ( M D M ) 30 , 3 2 9 , 5 0 9 . 3 0 10 , 1 8 9 , 3 5 9 30 3 . 1 3 MIS C E L L A N E O U S I N T A N G I B L E P L A N T - S A A S - 2 Y E A R L I F E 67 , 0 9 5 . 7 1 18 , 5 8 2 30 3 . 1 3 MIS C E L L A N E O U S I N T A N G I B L E P L A N T - S A A S - 3 Y E A R L I F E 59 5 , 5 8 4 . 5 0 56 , 6 8 8 30 3 . 1 3 MIS C E L L A N E O U S I N T A N G I B L E P L A N T - S A A S - 5 Y E A R L I F E 6, 5 5 4 , 4 6 0 . 9 2 49 6 , 4 1 3 38 9 . 2 0 LA N D 10 , 1 4 8 , 5 5 9 . 8 1 TO T A L A M O R T I Z A B L E A N D L A N D - C O M M O N P L A N T 33 7 , 1 2 9 , 9 9 6 . 4 5 15 8 , 6 5 6 , 1 5 5 TO T A L E L E C T R I C , G A S A N D C O M M O N P L A N T 7,0 4 1 , 8 0 5 , 3 5 4 . 0 6 2,4 6 6 , 8 9 2 , 8 6 5 ** 5- Y E A R A M O R T I Z A T I O N O F R E S E R V E R E L A T E D T O A M O R T I Z A T I O N A C C O U N T I N G . _____________________________________________________________________________________________ Avista Corporation December 31, 2021VI-15 Attachment C J. Spanos, Avista Page 69 of 800 PART VII. SERVICE LIFE STATISTICS _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-1 Attachment C J. Spanos, Avista Page 70 of 800 ELECTRIC PLANT _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-2 Attachment C J. Spanos, Avista Page 71 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 1 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-3 Attachment C J. Spanos, Avista Page 72 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 311.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-4 Attachment C J. Spanos, Avista Page 73 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 1 1 . 1 0 S T R U C T U R E S A N D I M P R O V E M E N T S - L A N D F I L L OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-5 Attachment C J. Spanos, Avista Page 74 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 311.10 STRUCTURES AND IMPROVEMENTS - LANDFILL ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-6 Attachment C J. Spanos, Avista Page 75 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 1 2 . 0 0 B O I L E R P L A N T E Q U I P M E N T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-7 Attachment C J. Spanos, Avista Page 76 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 312.00 BOILER PLANT EQUIPMENT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-8 Attachment C J. Spanos, Avista Page 77 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 1 3 . 0 0 E N G I N E S A N D E N G I N E - D R I V E N G E N E R A T O R S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-9 Attachment C J. Spanos, Avista Page 78 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 313.00 ENGINES AND ENGINE-DRIVEN GENERATORS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-10 Attachment C J. Spanos, Avista Page 79 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 1 4 . 0 0 T U R B O G E N E R A T O R S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-11 Attachment C J. Spanos, Avista Page 80 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 314.00 TURBOGENERATORS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-12 Attachment C J. Spanos, Avista Page 81 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 1 5 . 0 0 A C C E S S O R Y E L E C T R I C E Q U I P M E N T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-13 Attachment C J. Spanos, Avista Page 82 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 315.00 ACCESSORY ELECTRIC EQUIPMENT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-14 Attachment C J. Spanos, Avista Page 83 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 1 6 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-15 Attachment C J. Spanos, Avista Page 84 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 316.00 MISCELLANEOUS POWER PLANT EQUIPMENT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-16 Attachment C J. Spanos, Avista Page 85 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 0 . 3 0 R E M O V I N G P R O P E R T Y O F O T H E R S SM O O T H S U R V I V O R C U R V E _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-17 Attachment C J. Spanos, Avista Page 86 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 0 . 3 1 T W I N C R E E K C H A N N E L R E S T O R A T I O N OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-18 Attachment C J. Spanos, Avista Page 87 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.31 TWIN CREEK CHANNEL RESTORATION ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-19 Attachment C J. Spanos, Avista Page 88 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 0 . 4 0 L A N D E A S E M E N T S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-20 Attachment C J. Spanos, Avista Page 89 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.40 LAND EASEMENTS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-21 Attachment C J. Spanos, Avista Page 90 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.40 LAND EASEMENTS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-22 Attachment C J. Spanos, Avista Page 91 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.40 LAND EASEMENTS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-23 Attachment C J. Spanos, Avista Page 92 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 0 . 4 1 L A N D E A S E M E N T S - C O N S E R V A T I O N - H A B I T A T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-24 Attachment C J. Spanos, Avista Page 93 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.41 LAND EASEMENTS - CONSERVATION - HABITAT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-25 Attachment C J. Spanos, Avista Page 94 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-26 Attachment C J. Spanos, Avista Page 95 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-27 Attachment C J. Spanos, Avista Page 96 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-28 Attachment C J. Spanos, Avista Page 97 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-29 Attachment C J. Spanos, Avista Page 98 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 1 . 1 0 S T R U C T U R E S A N D I M P R O V E M E N T S - F I S H A N D W I L D L I F E C O N S E R V A T I O N OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-30 Attachment C J. Spanos, Avista Page 99 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.10 STRUCTURES AND IMPROVEMENTS - FISH AND WILDLIFE CONSERVATION ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-31 Attachment C J. Spanos, Avista Page 100 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 1 . 2 0 S T R U C T U R E S A N D I M P R O V E M E N T S - R E C R E A T I O N OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-32 Attachment C J. Spanos, Avista Page 101 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.20 STRUCTURES AND IMPROVEMENTS - RECREATION ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-33 Attachment C J. Spanos, Avista Page 102 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.20 STRUCTURES AND IMPROVEMENTS - RECREATION ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-34 Attachment C J. Spanos, Avista Page 103 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 1 . 2 6 S T R U C T U R E S A N D I M P R O V E M E N T S - R E C R E A T I O N I N F O R M A T I O N A N D E D U C A T I O N OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-35 Attachment C J. Spanos, Avista Page 104 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.26 STRUCTURES AND IMPROVEMENTS - RECREATION INFORMATION AND EDUCATION ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-36 Attachment C J. Spanos, Avista Page 105 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 2 . 0 0 R E S E R V O I R S , D A M S A N D W A T E R W A Y S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-37 Attachment C J. Spanos, Avista Page 106 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.00 RESERVOIRS, DAMS AND WATERWAYS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-38 Attachment C J. Spanos, Avista Page 107 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.00 RESERVOIRS, DAMS AND WATERWAYS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-39 Attachment C J. Spanos, Avista Page 108 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.00 RESERVOIRS, DAMS AND WATERWAYS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-40 Attachment C J. Spanos, Avista Page 109 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 2 . 1 0 R E S E R V O I R S , D A M S A N D W A T E R W A Y S - F I S H A N D W I L D L I F E C O N S E R V A T I O N OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-41 Attachment C J. Spanos, Avista Page 110 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.10 RESERVOIRS, DAMS AND WATERWAYS - FISH AND WILDLIFE CONSERVATION ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-42 Attachment C J. Spanos, Avista Page 111 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 2 . 1 5 R E S E R V O I R S , D A M S A N D W A T E R W A Y S - F I S H A N D W I L D L I F E C O N S E R V A T I O N OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-43 Attachment C J. Spanos, Avista Page 112 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.15 RESERVOIRS, DAMS AND WATERWAYS - FISH AND WILDLIFE CONSERVATION ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-44 Attachment C J. Spanos, Avista Page 113 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 2 . 2 0 R E S E R V O I R S , D A M S A N D W A T E R W A Y S - R E C R E A T I O N OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-45 Attachment C J. Spanos, Avista Page 114 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.20 RESERVOIRS, DAMS AND WATERWAYS - RECREATION ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-46 Attachment C J. Spanos, Avista Page 115 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.20 RESERVOIRS, DAMS AND WATERWAYS - RECREATION ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-47 Attachment C J. Spanos, Avista Page 116 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 3 . 0 0 T U R B I N E S A N D G E N E R A T O R S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-48 Attachment C J. Spanos, Avista Page 117 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 333.00 TURBINES AND GENERATORS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-49 Attachment C J. Spanos, Avista Page 118 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 333.00 TURBINES AND GENERATORS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-50 Attachment C J. Spanos, Avista Page 119 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 333.00 TURBINES AND GENERATORS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-51 Attachment C J. Spanos, Avista Page 120 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 4 . 0 0 A C C E S S O R Y E L E C T R I C E Q U I P M E N T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-52 Attachment C J. Spanos, Avista Page 121 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 334.00 ACCESSORY ELECTRIC EQUIPMENT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-53 Attachment C J. Spanos, Avista Page 122 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 334.00 ACCESSORY ELECTRIC EQUIPMENT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-54 Attachment C J. Spanos, Avista Page 123 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 334.00 ACCESSORY ELECTRIC EQUIPMENT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-55 Attachment C J. Spanos, Avista Page 124 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 5 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-56 Attachment C J. Spanos, Avista Page 125 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.00 MISCELLANEOUS POWER PLANT EQUIPMENT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-57 Attachment C J. Spanos, Avista Page 126 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.00 MISCELLANEOUS POWER PLANT EQUIPMENT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-58 Attachment C J. Spanos, Avista Page 127 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.00 MISCELLANEOUS POWER PLANT EQUIPMENT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-59 Attachment C J. Spanos, Avista Page 128 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 5 . 1 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T - F I S H A N D W I L D L I F E C O N S E R V A T I O N OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-60 Attachment C J. Spanos, Avista Page 129 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.10 MISCELLANEOUS POWER PLANT EQUIPMENT - FISH AND WILDLIFE CONSERVATION ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-61 Attachment C J. Spanos, Avista Page 130 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 5 . 1 5 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T - F I S H A N D W I L D L I F E C O N S E R V A T I O N OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-62 Attachment C J. Spanos, Avista Page 131 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.15 MISCELLANEOUS POWER PLANT EQUIPMENT - FISH AND WILDLIFE CONSERVATION ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-63 Attachment C J. Spanos, Avista Page 132 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 5 . 2 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T - R E C R E A T I O N OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-64 Attachment C J. Spanos, Avista Page 133 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.20 MISCELLANEOUS POWER PLANT EQUIPMENT - RECREATION ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-65 Attachment C J. Spanos, Avista Page 134 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 3 6 . 0 0 R O A D S , R A I L R O A D S A N D B R I D G E S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-66 Attachment C J. Spanos, Avista Page 135 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 336.00 ROADS, RAILROADS AND BRIDGES ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-67 Attachment C J. Spanos, Avista Page 136 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 336.00 ROADS, RAILROADS AND BRIDGES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-68 Attachment C J. Spanos, Avista Page 137 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 336.00 ROADS, RAILROADS AND BRIDGES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-69 Attachment C J. Spanos, Avista Page 138 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 4 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-70 Attachment C J. Spanos, Avista Page 139 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 341.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-71 Attachment C J. Spanos, Avista Page 140 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 341.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-72 Attachment C J. Spanos, Avista Page 141 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 4 2 . 0 0 F U E L H O L D E R S , P R O D U C E R S A N D A C C E S S O R I E S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-73 Attachment C J. Spanos, Avista Page 142 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 342.00 FUEL HOLDERS, PRODUCERS AND ACCESSORIES ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-74 Attachment C J. Spanos, Avista Page 143 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 342.00 FUEL HOLDERS, PRODUCERS AND ACCESSORIES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-75 Attachment C J. Spanos, Avista Page 144 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 4 3 . 0 0 P R I M E M O V E R S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-76 Attachment C J. Spanos, Avista Page 145 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 343.00 PRIME MOVERS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-77 Attachment C J. Spanos, Avista Page 146 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 343.00 PRIME MOVERS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-78 Attachment C J. Spanos, Avista Page 147 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 4 4 . 0 0 G E N E R A T O R S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-79 Attachment C J. Spanos, Avista Page 148 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 344.00 GENERATORS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-80 Attachment C J. Spanos, Avista Page 149 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 344.00 GENERATORS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-81 Attachment C J. Spanos, Avista Page 150 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 4 4 . 0 1 G E N E R A T O R S - S O L A R OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-82 Attachment C J. Spanos, Avista Page 151 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 344.01 GENERATORS - SOLAR ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-83 Attachment C J. Spanos, Avista Page 152 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 4 5 . 0 0 A C C E S S O R Y E L E C T R I C E Q U I P M E N T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-84 Attachment C J. Spanos, Avista Page 153 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 345.00 ACCESSORY ELECTRIC EQUIPMENT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-85 Attachment C J. Spanos, Avista Page 154 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 4 5 . 0 1 A C C E S S O R Y E L E C T R I C E Q U I P M E N T - S O L A R OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-86 Attachment C J. Spanos, Avista Page 155 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 345.01 ACCESSORY ELECTRIC EQUIPMENT - SOLAR ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-87 Attachment C J. Spanos, Avista Page 156 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 4 6 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-88 Attachment C J. Spanos, Avista Page 157 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 346.00 MISCELLANEOUS POWER PLANT EQUIPMENT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-89 Attachment C J. Spanos, Avista Page 158 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 346.00 MISCELLANEOUS POWER PLANT EQUIPMENT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-90 Attachment C J. Spanos, Avista Page 159 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 5 0 . 3 0 R E M O V I N G P R O P E R T Y O F O T H E R S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-91 Attachment C J. Spanos, Avista Page 160 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 350.30 REMOVING PROPERTY OF OTHERS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-92 Attachment C J. Spanos, Avista Page 161 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 350.30 REMOVING PROPERTY OF OTHERS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-93 Attachment C J. Spanos, Avista Page 162 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 350.30 REMOVING PROPERTY OF OTHERS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-94 Attachment C J. Spanos, Avista Page 163 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 5 0 . 4 0 L A N D R I G H T S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-95 Attachment C J. Spanos, Avista Page 164 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 350.40 LAND RIGHTS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-96 Attachment C J. Spanos, Avista Page 165 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 350.40 LAND RIGHTS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-97 Attachment C J. Spanos, Avista Page 166 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 350.40 LAND RIGHTS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-98 Attachment C J. Spanos, Avista Page 167 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 5 2 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-99 Attachment C J. Spanos, Avista Page 168 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 352.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-100 Attachment C J. Spanos, Avista Page 169 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 352.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-101 Attachment C J. Spanos, Avista Page 170 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 352.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-102 Attachment C J. Spanos, Avista Page 171 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 5 3 . 0 0 S T A T I O N E Q U I P M E N T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-103 Attachment C J. Spanos, Avista Page 172 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 353.00 STATION EQUIPMENT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-104 Attachment C J. Spanos, Avista Page 173 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 353.00 STATION EQUIPMENT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-105 Attachment C J. Spanos, Avista Page 174 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 353.00 STATION EQUIPMENT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-106 Attachment C J. Spanos, Avista Page 175 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 5 4 . 0 0 T O W E R S A N D F I X T U R E S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-107 Attachment C J. Spanos, Avista Page 176 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 354.00 TOWERS AND FIXTURES ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-108 Attachment C J. Spanos, Avista Page 177 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 354.00 TOWERS AND FIXTURES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-109 Attachment C J. Spanos, Avista Page 178 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 354.00 TOWERS AND FIXTURES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-110 Attachment C J. Spanos, Avista Page 179 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 5 5 . 0 0 P O L E S A N D F I X T U R E S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-111 Attachment C J. Spanos, Avista Page 180 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 355.00 POLES AND FIXTURES ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-112 Attachment C J. Spanos, Avista Page 181 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 355.00 POLES AND FIXTURES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-113 Attachment C J. Spanos, Avista Page 182 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 355.00 POLES AND FIXTURES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-114 Attachment C J. Spanos, Avista Page 183 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 5 6 . 0 0 O V E R H E A D C O N D U C T O R S A N D D E V I C E S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-115 Attachment C J. Spanos, Avista Page 184 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 356.00 OVERHEAD CONDUCTORS AND DEVICES ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-116 Attachment C J. Spanos, Avista Page 185 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 356.00 OVERHEAD CONDUCTORS AND DEVICES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-117 Attachment C J. Spanos, Avista Page 186 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 356.00 OVERHEAD CONDUCTORS AND DEVICES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-118 Attachment C J. Spanos, Avista Page 187 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 5 7 . 0 0 U N D E R G R O U N D C O N D U I T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-119 Attachment C J. Spanos, Avista Page 188 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 357.00 UNDERGROUND CONDUIT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-120 Attachment C J. Spanos, Avista Page 189 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 357.00 UNDERGROUND CONDUIT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-121 Attachment C J. Spanos, Avista Page 190 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 5 8 . 0 0 U N D E R G R O U N D C O N D U C T O R S A N D D E V I C E S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-122 Attachment C J. Spanos, Avista Page 191 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 358.00 UNDERGROUND CONDUCTORS AND DEVICES ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-123 Attachment C J. Spanos, Avista Page 192 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 358.00 UNDERGROUND CONDUCTORS AND DEVICES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-124 Attachment C J. Spanos, Avista Page 193 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 5 9 . 0 0 R O A D S A N D T R A I L S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-125 Attachment C J. Spanos, Avista Page 194 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 359.00 ROADS AND TRAILS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-126 Attachment C J. Spanos, Avista Page 195 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 359.00 ROADS AND TRAILS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-127 Attachment C J. Spanos, Avista Page 196 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 359.00 ROADS AND TRAILS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-128 Attachment C J. Spanos, Avista Page 197 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 6 0 . 4 0 L A N D - E A S E M E N T S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-129 Attachment C J. Spanos, Avista Page 198 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 360.40 LAND - EASEMENTS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-130 Attachment C J. Spanos, Avista Page 199 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 6 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-131 Attachment C J. Spanos, Avista Page 200 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 361.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-132 Attachment C J. Spanos, Avista Page 201 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 361.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-133 Attachment C J. Spanos, Avista Page 202 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 361.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-134 Attachment C J. Spanos, Avista Page 203 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 6 2 . 0 0 S T A T I O N E Q U I P M E N T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-135 Attachment C J. Spanos, Avista Page 204 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 362.00 STATION EQUIPMENT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-136 Attachment C J. Spanos, Avista Page 205 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 362.00 STATION EQUIPMENT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-137 Attachment C J. Spanos, Avista Page 206 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 362.00 STATION EQUIPMENT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-138 Attachment C J. Spanos, Avista Page 207 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 6 4 . 0 0 P O L E S , T O W E R S A N D F I X T U R E S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-139 Attachment C J. Spanos, Avista Page 208 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 364.00 POLES, TOWERS AND FIXTURES ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-140 Attachment C J. Spanos, Avista Page 209 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 364.00 POLES, TOWERS AND FIXTURES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-141 Attachment C J. Spanos, Avista Page 210 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 6 5 . 0 0 O V E R H E A D C O N D U C T O R S A N D D E V I C E S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-142 Attachment C J. Spanos, Avista Page 211 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 365.00 OVERHEAD CONDUCTORS AND DEVICES ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-143 Attachment C J. Spanos, Avista Page 212 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 365.00 OVERHEAD CONDUCTORS AND DEVICES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-144 Attachment C J. Spanos, Avista Page 213 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 365.00 OVERHEAD CONDUCTORS AND DEVICES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-145 Attachment C J. Spanos, Avista Page 214 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 6 6 . 0 0 U N D E R G R O U N D C O N D U I T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-146 Attachment C J. Spanos, Avista Page 215 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 366.00 UNDERGROUND CONDUIT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-147 Attachment C J. Spanos, Avista Page 216 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 366.00 UNDERGROUND CONDUIT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-148 Attachment C J. Spanos, Avista Page 217 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 366.00 UNDERGROUND CONDUIT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-149 Attachment C J. Spanos, Avista Page 218 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 6 7 . 0 0 U N D E R G R O U N D C O N D U C T O R S A N D D E V I C E S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-150 Attachment C J. Spanos, Avista Page 219 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 367.00 UNDERGROUND CONDUCTORS AND DEVICES ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-151 Attachment C J. Spanos, Avista Page 220 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 367.00 UNDERGROUND CONDUCTORS AND DEVICES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-152 Attachment C J. Spanos, Avista Page 221 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 367.00 UNDERGROUND CONDUCTORS AND DEVICES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-153 Attachment C J. Spanos, Avista Page 222 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 6 8 . 0 0 L I N E T R A N S F O R M E R S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-154 Attachment C J. Spanos, Avista Page 223 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 368.00 LINE TRANSFORMERS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-155 Attachment C J. Spanos, Avista Page 224 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 368.00 LINE TRANSFORMERS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-156 Attachment C J. Spanos, Avista Page 225 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T S 3 6 9 . 1 0 , 3 6 9 . 2 0 A N D 3 6 9 . 3 0 U N D E R G R O U N D A N D O V E R H E A D S E R V I C E S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-157 Attachment C J. Spanos, Avista Page 226 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 369.10, 369.20 AND 369.30 UNDERGROUND AND OVERHEAD SERVICES ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-158 Attachment C J. Spanos, Avista Page 227 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 369.10, 369.20 AND 369.30 UNDERGROUND AND OVERHEAD SERVICES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-159 Attachment C J. Spanos, Avista Page 228 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 369.10, 369.20 AND 369.30 UNDERGROUND AND OVERHEAD SERVICES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-160 Attachment C J. Spanos, Avista Page 229 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 7 0 . 1 0 M E T E R S - I D A H O OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-161 Attachment C J. Spanos, Avista Page 230 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 370.10 METERS - IDAHO ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-162 Attachment C J. Spanos, Avista Page 231 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 370.10 METERS - IDAHO ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-163 Attachment C J. Spanos, Avista Page 232 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 370.10 METERS - IDAHO ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-164 Attachment C J. Spanos, Avista Page 233 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 370.10 METERS - IDAHO ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-165 Attachment C J. Spanos, Avista Page 234 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 370.10 METERS - IDAHO ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-166 Attachment C J. Spanos, Avista Page 235 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 370.10 METERS - IDAHO ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-167 Attachment C J. Spanos, Avista Page 236 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 7 0 . 3 0 M E T E R S - W A S H I N G T O N S T A N D A R D OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-168 Attachment C J. Spanos, Avista Page 237 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 370.30 METERS - WASHINGTON STANDARD ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-169 Attachment C J. Spanos, Avista Page 238 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 370.30 METERS - WASHINGTON STANDARD ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-170 Attachment C J. Spanos, Avista Page 239 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 370.30 METERS - WASHINGTON STANDARD ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-171 Attachment C J. Spanos, Avista Page 240 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 370.30 METERS - WASHINGTON STANDARD ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-172 Attachment C J. Spanos, Avista Page 241 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 7 0 . 4 0 M E T E R S - W A S H I N G T O N A M I OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-173 Attachment C J. Spanos, Avista Page 242 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 370.40 METERS - WASHINGTON AMI ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-174 Attachment C J. Spanos, Avista Page 243 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 7 1 . 0 0 I N S T A L L A T I O N S O N C U S T O M E R S ' P R E M I S E S - C A T A L Y S T B U I L D I N G OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-175 Attachment C J. Spanos, Avista Page 244 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 371.00 INSTALLATIONS ON CUSTOMERS' PREMISES - CATALYST BUILDING ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-176 Attachment C J. Spanos, Avista Page 245 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T S 3 7 1 . 0 1 A N D 3 7 1 . 0 2 E L E C T R I C V E H I C L E C H A R G I N G S T A T I O N OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-177 Attachment C J. Spanos, Avista Page 246 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 371.01 AND 371.02 ELECTRIC VEHICLE CHARGING STATION ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-178 Attachment C J. Spanos, Avista Page 247 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T S 3 7 3 . 1 0 , 3 7 3 . 2 0 , 3 7 3 . 3 0 , 3 7 3 . 4 0 A N D 3 7 3 . 5 0 S T R E E T L I G H T I N G A N D S I G N A L S Y S T E M S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-179 Attachment C J. Spanos, Avista Page 248 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 373.10, 373.20, 373.30, 373.40 AND 373.50 STREET LIGHTING AND SIGNAL SYSTEMS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-180 Attachment C J. Spanos, Avista Page 249 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 373.10, 373.20, 373.30, 373.40 AND 373.50 STREET LIGHTING AND SIGNAL SYSTEMS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-181 Attachment C J. Spanos, Avista Page 250 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C P L A N T AC C O U N T 3 9 0 . 1 0 S T R U C T U R E S A N D I M P R O V E M E N T S - C O M P A N Y OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-182 Attachment C J. Spanos, Avista Page 251 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-183 Attachment C J. Spanos, Avista Page 252 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-184 Attachment C J. Spanos, Avista Page 253 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-185 Attachment C J. Spanos, Avista Page 254 of 800 GAS PLANT _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-186 Attachment C J. Spanos, Avista Page 255 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 5 0 . 2 0 R I G H T S O F W A Y OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-187 Attachment C J. Spanos, Avista Page 256 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 350.20 RIGHTS OF WAY ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-188 Attachment C J. Spanos, Avista Page 257 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 350.20 RIGHTS OF WAY ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-189 Attachment C J. Spanos, Avista Page 258 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T S 3 5 1 . 1 0 , 3 5 1 . 2 0 , 3 5 1 . 3 0 A N D 3 5 1 . 4 0 S T R U C T U R E S A N D I M P R O V E M E N T S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-190 Attachment C J. Spanos, Avista Page 259 of 800 AVISTA CORPORATION GAS PLANT ACCOUNTS 351.10, 351.20, 351.30 AND 351.40 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-191 Attachment C J. Spanos, Avista Page 260 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 5 2 . 0 0 W E L L S - S T O R A G E W E L L S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-192 Attachment C J. Spanos, Avista Page 261 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 352.00 WELLS - STORAGE WELLS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-193 Attachment C J. Spanos, Avista Page 262 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 352.00 WELLS - STORAGE WELLS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-194 Attachment C J. Spanos, Avista Page 263 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 352.00 WELLS - STORAGE WELLS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-195 Attachment C J. Spanos, Avista Page 264 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 352.00 WELLS - STORAGE WELLS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-196 Attachment C J. Spanos, Avista Page 265 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 5 2 . 2 0 W E L L S - R E S E R V O I R S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-197 Attachment C J. Spanos, Avista Page 266 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 352.20 WELLS - RESERVOIRS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-198 Attachment C J. Spanos, Avista Page 267 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 5 2 . 3 0 W E L L S - N O N - R E C O V E R A B L E G A S SM O O T H S U R V I V O R C U R V E _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-199 Attachment C J. Spanos, Avista Page 268 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 5 3 . 0 0 L I N E S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-200 Attachment C J. Spanos, Avista Page 269 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 353.00 LINES ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-201 Attachment C J. Spanos, Avista Page 270 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 353.00 LINES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-202 Attachment C J. Spanos, Avista Page 271 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 5 4 . 0 0 C O M P R E S S O R S T A T I O N E Q U I P M E N T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-203 Attachment C J. Spanos, Avista Page 272 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 354.00 COMPRESSOR STATION EQUIPMENT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-204 Attachment C J. Spanos, Avista Page 273 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 354.00 COMPRESSOR STATION EQUIPMENT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-205 Attachment C J. Spanos, Avista Page 274 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 5 5 . 0 0 M E A S U R I N G A N D R E G U L A T I N G E Q U I P M E N T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-206 Attachment C J. Spanos, Avista Page 275 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 355.00 MEASURING AND REGULATING EQUIPMENT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-207 Attachment C J. Spanos, Avista Page 276 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 355.00 MEASURING AND REGULATING EQUIPMENT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-208 Attachment C J. Spanos, Avista Page 277 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 5 6 . 0 0 P U R I F I C A T I O N E Q U I P M E N T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-209 Attachment C J. Spanos, Avista Page 278 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 356.00 PURIFICATION EQUIPMENT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-210 Attachment C J. Spanos, Avista Page 279 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 356.00 PURIFICATION EQUIPMENT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-211 Attachment C J. Spanos, Avista Page 280 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 5 7 . 0 0 O T H E R E Q U I P M E N T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-212 Attachment C J. Spanos, Avista Page 281 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 357.00 OTHER EQUIPMENT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-213 Attachment C J. Spanos, Avista Page 282 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 357.00 OTHER EQUIPMENT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-214 Attachment C J. Spanos, Avista Page 283 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 357.00 OTHER EQUIPMENT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-215 Attachment C J. Spanos, Avista Page 284 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 357.00 OTHER EQUIPMENT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-216 Attachment C J. Spanos, Avista Page 285 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 7 4 . 4 0 L A N D - E A S E M E N T S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-217 Attachment C J. Spanos, Avista Page 286 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 374.40 LAND - EASEMENTS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-218 Attachment C J. Spanos, Avista Page 287 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 7 5 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-219 Attachment C J. Spanos, Avista Page 288 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 375.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-220 Attachment C J. Spanos, Avista Page 289 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 375.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-221 Attachment C J. Spanos, Avista Page 290 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 375.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-222 Attachment C J. Spanos, Avista Page 291 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 375.00 STRUCTURES AND IMPROVEMENTS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-223 Attachment C J. Spanos, Avista Page 292 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 7 6 . 0 0 M A I N S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-224 Attachment C J. Spanos, Avista Page 293 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 376.00 MAINS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-225 Attachment C J. Spanos, Avista Page 294 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 376.00 MAINS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-226 Attachment C J. Spanos, Avista Page 295 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 376.00 MAINS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-227 Attachment C J. Spanos, Avista Page 296 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 376.00 MAINS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-228 Attachment C J. Spanos, Avista Page 297 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 376.00 MAINS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-229 Attachment C J. Spanos, Avista Page 298 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 376.00 MAINS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-230 Attachment C J. Spanos, Avista Page 299 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 7 8 . 0 0 M E A S U R I N G A N D R E G U L A T I N G E Q U I P M E N T - G E N E R A L OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-231 Attachment C J. Spanos, Avista Page 300 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 378.00 MEASURING AND REGULATING EQUIPMENT - GENERAL ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-232 Attachment C J. Spanos, Avista Page 301 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 378.00 MEASURING AND REGULATING EQUIPMENT - GENERAL ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-233 Attachment C J. Spanos, Avista Page 302 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 378.00 MEASURING AND REGULATING EQUIPMENT - GENERAL ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-234 Attachment C J. Spanos, Avista Page 303 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 378.00 MEASURING AND REGULATING EQUIPMENT - GENERAL ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-235 Attachment C J. Spanos, Avista Page 304 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 7 9 . 0 0 M E A S U R I N G A N D R E G U L A T I N G E Q U I P M E N T - C I T Y G A T E OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-236 Attachment C J. Spanos, Avista Page 305 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 379.00 MEASURING AND REGULATING EQUIPMENT - CITY GATE ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-237 Attachment C J. Spanos, Avista Page 306 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 379.00 MEASURING AND REGULATING EQUIPMENT - CITY GATE ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-238 Attachment C J. Spanos, Avista Page 307 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 379.00 MEASURING AND REGULATING EQUIPMENT - CITY GATE ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-239 Attachment C J. Spanos, Avista Page 308 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 379.00 MEASURING AND REGULATING EQUIPMENT - CITY GATE ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-240 Attachment C J. Spanos, Avista Page 309 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 8 0 . 0 0 S E R V I C E S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-241 Attachment C J. Spanos, Avista Page 310 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 380.00 SERVICES ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-242 Attachment C J. Spanos, Avista Page 311 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 380.00 SERVICES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-243 Attachment C J. Spanos, Avista Page 312 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 380.00 SERVICES ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-244 Attachment C J. Spanos, Avista Page 313 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 380.00 SERVICES ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-245 Attachment C J. Spanos, Avista Page 314 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 8 1 . 0 0 M E T E R S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-246 Attachment C J. Spanos, Avista Page 315 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 381.00 METERS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-247 Attachment C J. Spanos, Avista Page 316 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 381.00 METERS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-248 Attachment C J. Spanos, Avista Page 317 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 381.00 METERS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-249 Attachment C J. Spanos, Avista Page 318 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 381.00 METERS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-250 Attachment C J. Spanos, Avista Page 319 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 8 1 . 0 0 M E T E R S - W A S H I N G T O N A M I OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-251 Attachment C J. Spanos, Avista Page 320 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 381.00 METERS - WASHINGTON AMI ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-252 Attachment C J. Spanos, Avista Page 321 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 8 5 . 0 0 I N D U S T R I A L M E A S U R I N G A N D R E G U L A T I N G S T A T I O N E Q U I P M E N T OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-253 Attachment C J. Spanos, Avista Page 322 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 385.00 INDUSTRIAL MEASURING AND REGULATING STATION EQUIPMENT ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-254 Attachment C J. Spanos, Avista Page 323 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 385.00 INDUSTRIAL MEASURING AND REGULATING STATION EQUIPMENT ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-255 Attachment C J. Spanos, Avista Page 324 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 8 9 . 4 2 L A N D E A S E M E N T S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-256 Attachment C J. Spanos, Avista Page 325 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 389.42 LAND EASEMENTS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-257 Attachment C J. Spanos, Avista Page 326 of 800 AV I S T A C O R P O R A T I O N GA S P L A N T AC C O U N T 3 9 0 . 1 0 S T R U C T U R E S A N D I M P R O V E M E N T S - C O M P A N Y OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-258 Attachment C J. Spanos, Avista Page 327 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-259 Attachment C J. Spanos, Avista Page 328 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-260 Attachment C J. Spanos, Avista Page 329 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-261 Attachment C J. Spanos, Avista Page 330 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-262 Attachment C J. Spanos, Avista Page 331 of 800 COMMON PLANT _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-263 Attachment C J. Spanos, Avista Page 332 of 800 AV I S T A C O R P O R A T I O N CO M M O N P L A N T AC C O U N T 3 9 0 . 1 0 S T R U C T U R E S A N D I M P R O V E M E N T S - C O M P A N Y OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-264 Attachment C J. Spanos, Avista Page 333 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-265 Attachment C J. Spanos, Avista Page 334 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-266 Attachment C J. Spanos, Avista Page 335 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-267 Attachment C J. Spanos, Avista Page 336 of 800 ELECTRIC, GAS AND COMMON PLANT _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-268 Attachment C J. Spanos, Avista Page 337 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C , G A S A N D C O M M O N P L A N T AC C O U N T 3 9 2 . 1 0 T R A N S P O R T A T I O N E Q U I P M E N T - A U T O S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-269 Attachment C J. Spanos, Avista Page 338 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 392.10 TRANSPORTATION EQUIPMENT - AUTOS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-270 Attachment C J. Spanos, Avista Page 339 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C , G A S A N D C O M M O N P L A N T AC C O U N T 3 9 2 . 2 0 T R A N S P O R T A T I O N E Q U I P M E N T - L I G H T T R U C K S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-271 Attachment C J. Spanos, Avista Page 340 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 392.20 TRANSPORTATION EQUIPMENT - LIGHT TRUCKS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-272 Attachment C J. Spanos, Avista Page 341 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C , G A S A N D C O M M O N P L A N T AC C O U N T 3 9 2 . 3 0 T R A N S P O R T A T I O N E Q U I P M E N T - M E D I U M T R U C K S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-273 Attachment C J. Spanos, Avista Page 342 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 392.30 TRANSPORTATION EQUIPMENT - MEDIUM TRUCKS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-274 Attachment C J. Spanos, Avista Page 343 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 392.30 TRANSPORTATION EQUIPMENT - MEDIUM TRUCKS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-275 Attachment C J. Spanos, Avista Page 344 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C , G A S A N D C O M M O N P L A N T AC C O U N T 3 9 2 . 4 0 T R A N S P O R T A T I O N E Q U I P M E N T - H E A V Y T R U C K S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-276 Attachment C J. Spanos, Avista Page 345 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 392.40 TRANSPORTATION EQUIPMENT - HEAVY TRUCKS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-277 Attachment C J. Spanos, Avista Page 346 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C , G A S A N D C O M M O N P L A N T AC C O U N T 3 9 2 . 5 0 T R A N S P O R T A T I O N E Q U I P M E N T - O T H E R OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-278 Attachment C J. Spanos, Avista Page 347 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 392.50 TRANSPORTATION EQUIPMENT - OTHER ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-279 Attachment C J. Spanos, Avista Page 348 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 392.50 TRANSPORTATION EQUIPMENT - OTHER ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-280 Attachment C J. Spanos, Avista Page 349 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 392.50 TRANSPORTATION EQUIPMENT - OTHER ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-281 Attachment C J. Spanos, Avista Page 350 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C , G A S A N D C O M M O N P L A N T AC C O U N T 3 9 2 . 6 0 T R A N S P O R T A T I O N E Q U I P M E N T - A I R P L A N E OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-282 Attachment C J. Spanos, Avista Page 351 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 392.60 TRANSPORTATION EQUIPMENT - AIRPLANE ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-283 Attachment C J. Spanos, Avista Page 352 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C , G A S A N D C O M M O N P L A N T AC C O U N T 3 9 6 . 3 0 P O W E R O P E R A T E D E Q U I P M E N T - M E D I U M T R U C K S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-284 Attachment C J. Spanos, Avista Page 353 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 396.30 POWER OPERATED EQUIPMENT - MEDIUM TRUCKS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-285 Attachment C J. Spanos, Avista Page 354 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C , G A S A N D C O M M O N P L A N T AC C O U N T 3 9 6 . 4 0 P O W E R O P E R A T E D E Q U I P M E N T - H E A V Y T R U C K S OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-286 Attachment C J. Spanos, Avista Page 355 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 396.40 POWER OPERATED EQUIPMENT - HEAVY TRUCKS ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-287 Attachment C J. Spanos, Avista Page 356 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 396.40 POWER OPERATED EQUIPMENT - HEAVY TRUCKS ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-288 Attachment C J. Spanos, Avista Page 357 of 800 AV I S T A C O R P O R A T I O N EL E C T R I C , G A S A N D C O M M O N P L A N T AC C O U N T 3 9 6 . 5 0 P O W E R O P E R A T E D E Q U I P M E N T - O T H E R OR I G I N A L A N D S M O O T H S U R V I V O R C U R V E S _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-289 Attachment C J. Spanos, Avista Page 358 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 396.50 POWER OPERATED EQUIPMENT - OTHER ORIGINAL LIFE TABLE _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-290 Attachment C J. Spanos, Avista Page 359 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 396.50 POWER OPERATED EQUIPMENT - OTHER ORIGINAL LIFE TABLE, CONT. _____________________________________________________________________________________________ Avista Corporation December 31, 2021VII-291 Attachment C J. Spanos, Avista Page 360 of 800 PART VIII. NET SALVAGE STATISTICS _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-1 Attachment C J. Spanos, Avista Page 361 of 800 AV I S T A C O R P O R A T I O N CA L C U L A T I O N O F W E I G H T E D N E T S A L V A G E P E R C E N T F O R G E N E R A T I O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 TE R M I N A L R E T I R E M E N T S I N T E R I M R E T I R E M E N T S NE T N E T N E T N E T T O T A L E S T I M A T E D SA L V A G E S A L V A G E SA L V A G E S A L V A G E TO T A L N E T NE T AC C O U N T RE T I R E M E N T S AM O U N T PE R C E N T R E T I R E M E N T S AM O U N T PE R C E N T R E T I R E M E N T S S A L V A G E SA L V A G E (1 ) (2 ) (3 ) (4 ) = ( 3 ) / ( 2 ) (5 ) (6 ) = ( 5 ) * ( 7 ) (7 ) (8 ) = ( 2 ) + ( 5 ) (9 ) = ( 3 ) + ( 6 ) (1 0 ) = ( 9 ) / ( 8 ) ST E A M P R O D U C T I O N P L A N T KE T T L E F A L L S 31 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (2 1 , 9 9 8 , 6 7 8 ) 88 1 , 9 7 4 (4 ) (3 , 2 8 9 , 5 9 4 ) 29 6 , 0 6 3 (9 ) (2 5 , 2 8 8 , 2 7 2 ) 1,1 7 8 , 0 3 7 (5 ) 31 2 . 0 0 B O I L E R P L A N T E Q U I P M E N T (3 7 , 1 5 3 , 0 7 9 ) 1,4 8 9 , 5 4 6 (4 ) (9 , 6 4 8 , 6 0 6 ) 86 8 , 3 7 5 (9 ) (4 6 , 8 0 1 , 6 8 6 ) 2,3 5 7 , 9 2 0 (5 ) 31 4 . 0 0 T U R B O G E N E R A T O R S (1 0 , 8 2 6 , 4 6 2 ) 43 4 , 0 5 6 (4 ) (7 , 8 0 5 , 6 2 7 ) 70 2 , 5 0 6 (9 ) (1 8 , 6 3 2 , 0 8 9 ) 1,1 3 6 , 5 6 2 (6 ) 31 5 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (9 , 2 6 5 , 2 7 2 ) 37 1 , 4 6 4 (4 ) (3 , 3 3 0 , 7 7 7 ) 29 9 , 7 7 0 (9 ) (1 2 , 5 9 6 , 0 4 9 ) 67 1 , 2 3 4 (5 ) 31 6 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T (1 , 9 7 6 , 0 2 5 ) 79 , 2 2 3 (4 ) (5 0 0 , 9 3 4 ) 45 , 0 8 4 (9 ) (2 , 4 7 6 , 9 5 9 ) 12 4 , 3 0 7 (5 ) T O T A L K E T T L E F A L L S (8 1 , 2 1 9 , 5 1 7 ) 3,2 5 6 , 2 6 3 (4 ) (2 4 , 5 7 5 , 5 3 8 ) 2,2 1 1 , 7 9 8 (9 ) (1 0 5 , 7 9 5 , 0 5 5 ) 5,4 6 8 , 0 6 1 (5 ) CO L S T R I P 3 A N D C O M M O N - I D A H O 31 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (1 9 , 4 9 0 , 2 7 1 ) 56 0 , 9 1 5 (3 ) (6 6 2 , 4 6 5 ) 59 , 6 2 2 (9 ) (2 0 , 1 5 2 , 7 3 6 ) 62 0 , 5 3 7 (3 ) 31 2 . 0 0 B O I L E R P L A N T E Q U I P M E N T (2 8 , 5 5 7 , 1 9 1 ) 82 1 , 8 5 4 (3 ) (1 , 8 6 7 , 6 1 0 ) 16 8 , 0 8 5 (9 ) (3 0 , 4 2 4 , 8 0 1 ) 98 9 , 9 3 9 (3 ) 31 3 . 0 0 E N G I N E S A N D E N G I N E - DR I V E N G E N E R A T O R S (1 7 4 , 2 3 0 ) 5,0 1 4 (3 ) (1 , 2 3 0 ) 11 1 (9 ) (1 7 5 , 4 6 1 ) 5,1 2 5 (3 ) 31 4 . 0 0 T U R B O G E N E R A T O R S (7 , 3 5 1 , 9 3 7 ) 21 1 , 5 8 3 (3 ) (9 7 8 , 8 7 2 ) 88 , 0 9 8 (9 ) (8 , 3 3 0 , 8 0 8 ) 29 9 , 6 8 1 (4 ) 31 5 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (3 , 5 3 1 , 4 9 7 ) 10 1 , 6 3 4 (3 ) (3 4 4 , 4 4 4 ) 31 , 0 0 0 (9 ) (3 , 8 7 5 , 9 4 0 ) 13 2 , 6 3 4 (3 ) 31 6 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T (3 , 3 2 3 , 7 3 4 ) 95 , 6 5 4 (3 ) (1 6 8 , 8 5 7 ) 15 , 1 9 7 (9 ) (3 , 4 9 2 , 5 9 0 ) 11 0 , 8 5 2 (3 ) T O T A L C O L S T R I P 3 A N D C O M M O N - I D A H O (6 2 , 4 2 8 , 8 6 0 ) 1,7 9 6 , 6 5 4 (3 ) (4 , 0 2 3 , 4 7 7 ) 36 2 , 1 1 3 (9 ) (6 6 , 4 5 2 , 3 3 7 ) 2,1 5 8 , 7 6 7 (3 ) CO L ST R I P 3 A N D C O M M O N - W A S H I N G T O N 31 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (3 7 , 2 8 9 , 8 6 7 ) 99 5 , 2 0 7 (3 ) (7 2 3 , 0 7 7 ) 65 , 0 7 7 (9 ) (3 8 , 0 1 2 , 9 4 4 ) 1,0 6 0 , 2 8 3 (3 ) 31 2 . 0 0 B O I L E R P L A N T E Q U I P M E N T (5 3 , 9 1 3 , 9 4 5 ) 1,4 3 8 , 8 7 6 (3 ) (2 , 0 4 6 , 9 1 7 ) 18 4 , 2 2 3 (9 ) (5 5 , 9 6 0 , 8 6 3 ) 1,6 2 3 , 0 9 9 (3 ) 31 3 . 0 0 E N G I N E S A N D E N G I N E - D R I V E N G E N E R A T O R S (3 3 1 , 8 3 6 ) 8,8 5 6 (3 ) (1 , 2 8 7 ) 11 6 (9 ) (3 3 3 , 1 2 3 ) 8,9 7 2 (3 ) 31 4 . 0 0 T U R B O G E N E R A T O R S (14 , 6 1 6 , 7 5 5 ) 39 0 , 0 9 8 (3 ) (1 , 0 9 7 , 5 9 9 ) 98 , 7 8 4 (9 ) (1 5 , 7 1 4 , 3 5 4 ) 48 8 , 8 8 2 (3 ) 31 5 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (7 , 0 0 1 , 5 5 5 ) 18 6 , 8 6 0 (3 ) (3 8 1 , 6 8 9 ) 34 , 3 5 2 (9 ) (7 , 3 8 3 , 2 4 4 ) 22 1 , 2 1 2 (3 ) 31 6 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T (6 , 4 0 5 , 4 8 1 ) 17 0 , 9 5 2 (3 ) (1 8 3 , 7 5 8 ) 16 , 5 3 8 (9 ) (6 , 5 8 9 , 2 3 9 ) 18 7 , 4 9 0 (3 ) T O T A L C O L S T R I P 3 A N D C O M M O N - W A S H I N G T O N (1 1 9 , 5 5 9 , 4 3 9 ) 3,1 9 0 , 8 4 9 (3 ) (4 , 4 3 4 , 3 2 8 ) 39 9 , 0 8 9 (9 ) (1 2 3 , 9 9 3 , 7 6 6 ) 3,5 8 9 , 9 3 8 (3 ) CO L S T R I P 4 - I D A H O 31 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (1 8 , 1 8 9 , 3 7 1 ) 68 2 , 8 7 2 (4 ) (5 8 7 , 0 4 4 ) 52 , 8 3 4 (9 ) (1 8 , 7 7 6 , 4 1 5 ) 73 5 , 7 0 6 (4 ) 31 2 . 0 0 B O I L E R P L A N T E Q U I P M E N T (2 0 , 4 1 8 , 2 8 0 ) 76 6 , 5 5 0 (4 ) (1 , 1 4 7 , 3 0 5 ) 10 3 , 2 5 7 (9 ) (2 1 , 5 6 5 , 5 8 5 ) 86 9 , 8 0 8 (4 ) 31 3 . 0 0 E N G I N E S A N D E N G I N E - D R I V E N G E N E R A T O R S (1 1 , 3 0 5 ) 42 4 (4 ) (8 9 ) 8 (9 ) (1 1 , 3 9 4 ) 43 2 (4 ) 31 4 . 0 0 T U R B O G E N E R A T O R S (5 , 3 8 0 , 8 6 4 ) 20 2 , 0 1 0 (4 ) (6 3 7 , 2 3 7 ) 57 , 3 5 1 (9 ) (6 , 0 1 8 , 1 0 1 ) 25 9 , 3 6 2 (4 ) 31 5 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (2 , 4 5 8 , 1 9 8 ) 92 , 2 8 7 (4 ) (2 1 9 , 5 5 9 ) 19 , 7 6 0 (9 ) (2 , 6 7 7 , 7 5 7 ) 11 2 , 0 4 7 (4 ) 31 6 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T (1 , 5 0 1 , 9 5 4 ) 56 , 3 8 7 (4 ) ( 72 , 33 0 ) 6,5 1 0 (9 ) (1 , 5 7 4 , 2 8 5 ) 62 , 8 9 7 (4 ) T O T A L C O L S T R I P 4 - I D A H O (4 7 , 9 5 9 , 9 7 3 ) 1,8 0 0 , 5 3 0 (4 ) (2 , 6 6 3 , 5 6 5 ) 23 9 , 7 2 1 (9 ) (5 0 , 6 2 3 , 5 3 7 ) 2,0 4 0 , 2 5 1 (4 ) COL S T R I P 4 - W A S H I N G T O N 31 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (3 4 , 7 8 3 , 6 6 8 ) 1,2 1 5 , 1 9 8 (3 ) (6 3 3 , 3 0 6 ) 56 , 9 9 8 (9 ) (3 5 , 4 1 6 , 9 7 4 ) 1,2 7 2 , 1 9 6 (4 ) 31 2 . 0 0 B O I L E R P L A N T E Q U I P M E N T (3 8 , 1 4 2 , 2 0 7 ) 1,3 3 2 , 5 3 2 (3 ) (1 , 2 4 9 , 6 8 5 ) 11 2 , 4 7 2 (9 ) (3 9 , 3 9 1 , 8 9 2 ) 1,4 4 5 , 0 0 3 (4 ) 31 3 . 0 0 E N G I N E S A N D E N G I N E - D R I V E N G E N E R A T O R S (2 0 , 9 9 1 ) 73 3 (3 ) (9 1 ) 8 (9 ) (2 1 , 0 8 3 ) 74 2 (4 ) 31 4 . 0 0 T U R B O G E N E R A T O R S (1 0 , 6 4 7 , 2 9 8 ) 37 1 , 9 7 3 (3 ) (7 1 3 , 7 5 4 ) 64 , 2 3 8 (9 ) (1 1 , 3 6 1 , 0 5 2 ) 43 6 , 2 1 1 (4 ) 31 5 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (4 , 7 4 4 , 6 3 3 ) 16 5 , 7 5 8 (3 ) (2 4 2 , 0 0 9 ) 21 , 7 8 1 (9 ) (4 , 9 8 6 , 6 4 2 ) 18 7 , 5 3 9 (4 ) 31 6 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T (2 , 8 9 0 , 0 0 3 ) 10 0 , 9 6 5 (3 ) (7 8 , 6 9 6 ) 7,0 8 3 (9 ) (2 , 9 6 8 , 6 9 9 ) 10 8 , 0 4 7 (4 ) T O T A L C O L S T R I P 4 - W A S H I N G T O N (9 1 , 2 2 8 , 8 0 0 ) 3,1 8 7 , 1 5 9 (3 ) (2 , 9 1 7 , 5 4 0 ) 26 2 , 5 7 9 (9 ) (9 4 , 1 4 6 , 3 4 0 ) 3,4 4 9 , 7 3 8 (4 ) TO T A L S T E A M P R O D U C T I O N P L A N T (4 0 2 , 3 9 6 , 5 8 8 ) 13 , 2 3 1 , 4 5 5 ( 3 ) (3 8 , 6 1 4 , 4 4 7 ) 3,4 7 5 , 3 0 0 (9 ) (4 4 1 , 0 1 1 , 0 3 5 ) 16 , 7 0 6 , 7 5 5 (4 ) _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-2 Attachment C J. Spanos, Avista Page 362 of 800 AV I S T A C O R P O R A T I O N CA L C U L A T I O N O F W E I G H T E D N E T S A L V A G E P E R C E N T F O R G E N E R A T I O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 TE R M I N A L R E T I R E M E N T S I N T E R I M R E T I R E M E N T S NE T N E T N E T N E T T O T A L E S T I M A T E D SA L V A G E S A L V A G E SA L V A G E S A L V A G E TO T A L N E T NE T AC C O U N T RE T I R E M E N T S AM O U N T PE R C E N T R E T I R E M E N T S AM O U N T PE R C E N T R E T I R E M E N T S S A L V A G E SA L V A G E (1 ) (2 ) (3 ) (4 ) = ( 3 ) / ( 2 ) (5 ) (6 ) = ( 5 ) * ( 7 ) (7 ) (8 ) = ( 2 ) + ( 5 ) (9 ) = ( 3 ) + ( 6 ) (1 0 ) = ( 9 ) / ( 8 ) HY D R O P R O D U C T I O N P L A N T MO N R O E S T R E E T 33 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (6 , 5 3 3 , 6 0 2 ) 1 6 0 , 9 7 1 ( 2 ) ( 1 , 6 6 5 , 3 8 5 ) 2 1 6 , 5 0 0 ( 1 3 ) ( 8 , 1 9 8 , 9 8 6 ) 3 7 7 , 4 7 1 ( 5 ) 33 1 . 2 0 S T R U C T U R E S A N D I M P R O V E M E N T S - R E C R E A T I O N ( 1 , 2 5 8 , 5 2 3 ) 3 1 , 0 0 7 ( 2 ) ( 2 , 7 7 8 , 5 0 2 ) 3 6 1 , 2 0 5 ( 1 3 ) ( 4 , 0 3 7 , 0 2 5 ) 3 9 2 , 2 1 2 ( 1 0 ) 33 2 . 0 0 R E S E R V O I R S , D A M S A N D W A T E R W A Y S (7 , 6 8 8 , 0 6 8 ) 1 8 9 , 4 1 4 ( 2 ) ( 2 , 2 8 3 , 9 5 2 ) 2 9 6 , 9 1 4 ( 1 3 ) ( 9 , 9 7 2 , 0 2 0 ) 4 8 6 , 3 2 8 ( 5 ) 33 3 . 0 0 T U R B I N E S A N D G E N E R A T O R S (5 , 5 3 5 , 4 0 1 ) 1 3 6 , 3 7 8 ( 2 ) ( 6 , 0 3 9 , 5 7 0 ) 7 8 5 , 1 4 4 ( 1 3 ) ( 1 1 , 5 7 4 , 9 7 1 ) 9 2 1 , 5 2 2 ( 8 ) 33 4 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (4 1 1 , 0 1 0 ) 1 0 , 1 2 6 ( 2 ) ( 2 , 6 2 3 , 2 3 2 ) 3 4 1 , 0 2 0 ( 1 3 ) ( 3 , 0 3 4 , 2 4 2 ) 3 5 1 , 1 4 6 ( 1 2 ) 33 5 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T ( 1 5 , 9 5 5 ) 3 9 3 ( 2 ) ( 1 7 , 6 0 8 ) 2 , 2 8 9 ( 1 3 ) ( 3 3 , 5 6 4 ) 2 , 6 8 2 ( 8 ) 33 6 . 0 0 R O A D S , R A I L R O A D S A N D B R I D G E S (6 , 7 3 2 ) 1 6 6 ( 2 ) ( 4 3 , 7 1 6 ) 5 , 6 8 3 ( 1 3 ) ( 5 0 , 4 4 8 ) 5 , 8 4 9 ( 1 2 ) T O T A L M O N R O E S T R E E T (2 1 , 4 4 9 , 2 9 1 ) 5 2 8 , 4 5 5 ( 2 ) ( 1 5 , 4 5 1 , 9 6 6 ) 2 , 0 0 8 , 7 5 6 ( 1 3 ) ( 3 6 , 9 0 1 , 2 5 6 ) 2 , 5 3 7 , 2 1 1 ( 7 ) LIT T L E F A L L S 33 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (4 , 7 8 3 , 1 7 2 ) 9 3 , 8 0 9 ( 2 ) ( 6 8 8 , 7 5 7 ) 8 9 , 5 3 8 ( 1 3 ) ( 5 , 4 7 1 , 9 3 0 ) 1 8 3 , 3 4 7 ( 3 ) 33 2 . 0 0 R E S E R V O I R S , D A M S A N D W A T E R W A Y S (5 , 2 9 6 , 4 4 2 ) 1 0 3 , 8 7 5 ( 2 ) ( 1 , 0 8 3 , 1 1 0 ) 1 4 0 , 8 0 4 ( 1 3 ) ( 6 , 3 7 9 , 5 5 2 ) 2 4 4 , 6 7 9 ( 4 ) 33 2 . 2 0 R E S E R V O I R S , D A M S A N D W A T E R W A Y S - R E C R E A T I O N ( 7 , 0 9 2 ) 1 3 9 ( 2 ) ( 7 , 2 7 3 ) 9 4 6 ( 1 3 ) ( 1 4 , 3 6 6 ) 1 , 0 8 5 ( 8 ) 33 3 . 0 0 T U R B I N E S A N D G E N E R A T O R S (2 9 , 9 8 3 , 0 8 9 ) 5 8 8 , 0 3 5 ( 2 ) ( 9 , 2 1 7 , 4 5 0 ) 1 , 1 9 8 , 2 6 9 ( 1 3 ) ( 3 9 , 2 0 0 , 5 3 9 ) 1 , 7 8 6 , 3 0 3 ( 5 ) 33 4 . 0 0 A C C E S S O R Y E L E C T R I C E Q U I P M E N T (5 , 9 1 8 , 7 9 3 ) 1 1 6 , 0 8 1 ( 2 ) ( 8 , 0 4 5 , 0 7 6 ) 1 , 0 4 5 , 8 6 0 ( 1 3 ) ( 1 3 , 9 6 3 , 8 6 9 ) 1 , 1 6 1 , 9 4 1 ( 8 ) 33 5 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T ( 4 0 2 , 0 3 0 ) 7 , 8 8 5 ( 2 ) ( 1 4 6 , 9 1 9 ) 1 9 , 0 9 9 ( 1 3 ) ( 5 4 8 , 9 4 8 ) 2 6 , 9 8 4 ( 5 ) T O T A L L I T T L E F A L L S (4 6 , 3 9 0 , 6 1 8 ) 9 0 9 , 8 2 3 (2 ) (1 9 , 1 8 8 , 5 8 6 ) 2,4 9 4 , 5 1 6 (13 ) (6 5 , 5 7 9 , 2 0 4 ) 3,4 0 4 , 3 3 9 (5 ) LO N G L A K E 33 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (6 , 7 3 9 , 8 7 0 ) 28 5 , 0 6 2 (4 ) (9 4 6 , 3 8 2 ) 12 3 , 0 3 0 (1 3 ) (7 , 6 8 6 , 2 5 2 ) 40 8 , 0 9 1 (5 ) 33 1 . 1 0 S T R U C T U R E S A N D I M P R O V E M E N T S - F I SH A N D W I L D L I F E C O N S E R V A T I O N (2 4 , 5 0 9 ) 1,0 3 7 (4 ) (4 1 , 8 6 9 ) 5,4 4 3 (1 3 ) (6 6 , 3 7 8 ) 6,4 8 0 (1 0 ) 33 1 . 2 0 S T R U C T U R E S A N D I M P R O V E M E N T S - R E C R E A T I O N (1 , 2 6 6 , 5 1 0 ) 53 , 5 6 7 (4 ) (4 5 4 , 1 7 2 ) 59 , 0 4 2 (1 3 ) (1 , 7 2 0 , 6 8 2 ) 11 2 , 6 0 9 (7 ) 33 2 . 0 0 R E S E R V O I R S , D A M S A N D W A T E R W A Y S (3 2 , 6 0 6 , 8 9 6 ) 1,3 7 9 , 1 0 4 (4 ) (5 , 0 8 7 , 9 7 9 ) 66 1 , 4 3 7 (1 3 ) (3 7 , 6 9 4 , 8 7 5 ) 2,0 4 0 , 5 4 1 (5 ) 33 2 . 1 0 R E S E R V O I R S , D A M S A N D W A T E R W A Y S - F I S H A N D W I L D L I F E C O N S E R V A T I O N (7 2 , 3 7 2 ) 3,0 6 1 (4 ) (1 1 , 4 0 9 ) 1,4 8 3 (1 3 ) (8 3 , 7 8 1 ) 4,5 4 4 (5 ) 33 2 . 2 0 R E S E R V O I R S , D A M S A N D WA T E R W A Y S - R E C R E A T I O N (4 7 , 5 2 7 ) 2,0 1 0 (4 ) (5 8 , 1 1 3 ) 7,5 5 5 (1 3 ) (1 0 5 , 6 3 9 ) 9,5 6 5 (9 ) 33 3 . 0 0 T U R B I N E S A N D G E N E R A T O R S (5 , 2 1 3 , 1 9 0 ) 22 0 , 4 9 1 (4 ) (3 , 5 2 2 , 6 0 8 ) 45 7 , 9 3 9 (1 3 ) (8 , 7 3 5 , 7 9 9 ) 67 8 , 4 3 0 (8 ) 33 4 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (1 , 5 7 5 , 3 1 9 ) 66 , 6 2 8 (4 ) (2 , 9 2 8 , 7 2 2 ) 38 0 , 7 3 4 (1 3 ) (4 , 5 0 4 , 0 4 1 ) 44 7 , 3 6 2 (1 0 ) 33 5 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T (5 9 0 , 8 2 4 ) 24 , 9 8 9 (4 ) (2 2 0 , 7 2 1 ) 28 , 6 9 4 (1 3 ) (8 1 1 , 5 4 6 ) 53 , 6 8 3 (7 ) 33 5 . 1 5 M I S C E L L A N E O U S E Q U I P M E N T - F I S H A N D W I L D L I F E C O N S E R V A T I O N (1 3 , 0 7 1 ) 55 3 (4 ) (1 , 5 2 1 ) 19 8 (1 3 ) (1 4 , 5 9 2 ) 75 1 (5 ) 33 5 . 2 0 M I S C E L L A N E O U S E Q U I P M E N T - R E C R E A T I O N (2 3 , 2 3 1 ) 98 3 (4 ) (2 , 4 6 6 ) 32 1 (1 3 ) (2 5 , 6 9 7 ) 1,3 0 3 (5 ) T O T A L L O N G L A K E (4 8 , 1 3 7 , 0 1 7 ) 2,0 3 5 , 9 4 8 (4 ) (1 3 , 2 7 5 , 9 6 4 ) 1,7 2 5 , 8 7 5 (1 3 ) (6 1 , 4 4 9 , 2 8 2 ) 3,7 6 3 , 3 5 8 (6 ) SP O K A N E U P P E R F A L L S 33 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (8 6 5 , 5 5 2 ) 23 , 9 3 3 (3 ) (2 4 9 , 0 2 7 ) 32 , 3 7 4 (1 3 ) (1 , 1 1 4 , 5 8 0 ) 56 , 3 0 6 (5 ) 33 1 . 2 0 S T RU C T U R E S A N D I M P R O V E M E N T S - R E C R E A T I O N (3 4 ) 1 (3 ) (5 , 9 4 6 ) 77 3 (1 3 ) (5 , 9 8 0 ) 77 4 (1 3 ) 33 2 . 0 0 RE S E R V O I R S , D A M S A N D W A T E R W A Y S (6 , 5 1 8 , 9 1 9 ) 18 0 , 2 5 1 (3 ) (1 , 2 0 9 , 6 5 4 ) 15 7 , 2 5 5 (1 3 ) (7 , 7 2 8 , 5 7 3 ) 33 7 , 5 0 6 (4 ) 33 3 . 0 0 T U R B I N E S A N D G E N E R A T O R S (5 3 0 , 6 5 4 ) 14 , 6 7 3 (3 ) (6 5 0 , 3 8 8 ) 84 , 5 5 0 (1 3 ) (1 , 1 8 1 , 0 4 2 ) 99 , 2 2 3 (8 ) 33 4 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (1 , 2 8 6 , 1 3 8 ) 35 , 5 6 2 (3 ) (3 , 0 1 2 , 6 6 1 ) 39 1 , 6 4 6 (1 3 ) (4 , 2 9 8 , 7 9 8 ) 42 7 , 2 0 8 (1 0 ) 33 5 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T (6 4 , 4 9 4 ) 1,7 8 3 (3 ) (3 9 , 9 5 6 ) 5,1 9 4 (1 3 ) (1 0 4 , 4 5 0 ) 6,9 7 8 (7 ) 33 6 . 0 0 R O A D S , R A I L R O A D S A N D B R I D G E S (3 9 7 , 6 0 8 ) 10 , 9 9 4 (3 ) (1 1 0 , 6 3 4 ) 14 , 3 8 2 (1 3 ) (5 0 8 , 2 4 2 ) 25 , 3 7 6 (5 ) T O T A L S P O K A N E U P P E R F A L L S (9 , 6 6 3 , 3 9 9 ) 26 7 , 1 9 7 (3 ) (5 , 2 7 8 , 2 6 5 ) 68 6 , 1 7 5 (1 3 ) (1 4 , 9 4 1 , 6 6 5 ) 95 3 , 3 7 2 (6 ) _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-3 Attachment C J. Spanos, Avista Page 363 of 800 AV I S T A C O R P O R A T I O N CA L C U L A T I O N O F W E I G H T E D N E T S A L V A G E P E R C E N T F O R G E N E R A T I O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 TE R M I N A L R E T I R E M E N T S I N T E R I M R E T I R E M E N T S NE T N E T N E T N E T T O T A L E S T I M A T E D SA L V A G E S A L V A G E SA L V A G E S A L V A G E TO T A L N E T NE T AC C O U N T RE T I R E M E N T S AM O U N T PE R C E N T R E T I R E M E N T S AM O U N T PE R C E N T R E T I R E M E N T S S A L V A G E SA L V A G E (1 ) (2 ) (3 ) (4 ) = ( 3 ) / ( 2 ) (5 ) (6 ) = ( 5 ) * ( 7 ) (7 ) (8 ) = ( 2 ) + ( 5 ) (9 ) = ( 3 ) + ( 6 ) (1 0 ) = ( 9 ) / ( 8 ) NIN E M I L E 33 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (1 7 , 9 6 7 , 4 7 2 ) 1 0 9 , 0 5 7 ( 1 ) ( 2 , 0 8 1 , 5 8 8 ) 2 7 0 , 6 0 6 ( 1 3 ) ( 2 0 , 0 4 9 , 0 6 0 ) 3 7 9 , 6 6 4 ( 2 ) 33 1 . 2 0 S T R U C T U R E S A N D I M P R O VE M E N T S - R E C R E A T I O N ( 2 5 2 , 3 7 6 ) 1 , 5 3 2 ( 1 ) ( 1 1 8 , 3 7 6 ) 1 5 , 3 8 9 ( 1 3 ) ( 3 7 0 , 7 5 2 ) 1 6 , 9 2 1 ( 5 ) 33 2 . 0 0 R E S E R V O I R S , D A M S A N D W A T E R W A Y S ( 2 6 , 7 6 7 , 9 4 1 ) 1 6 2 , 4 7 4 ( 1 ) ( 4 , 0 2 4 , 8 3 1 ) 5 2 3 , 2 2 8 ( 1 3 ) ( 3 0 , 7 9 2 , 7 7 2 ) 6 8 5 , 7 0 2 ( 2 ) 33 2 . 1 0 R E S E R V O I R S , D A M S A N D W A T E R W A Y S - FIS H A N D W I L D L I F E C O N S E R V A T I O N ( 6 7 , 1 7 4 ) 4 0 8 ( 1 ) ( 1 5 , 2 8 4 ) 1 , 9 8 7 ( 1 3 ) ( 8 2 , 4 5 8 ) 2 , 3 9 5 ( 3 ) 33 2 . 1 5 R E S E R V O I R S , D A M S A N D W A T E R W A Y S - F I S H A N D W I L D L I F E C O N S E R V A T I O N ( 8 , 8 4 9 ) 5 4 ( 1 ) ( 2 , 1 8 6 ) 2 8 4 ( 1 3 ) ( 1 1 , 0 3 4 ) 3 3 8 ( 3 ) 33 2 . 2 0 R E S E R V O I R S , D A M S A N D WA T E R W A Y S - R E C R E A T I O N ( 2 3 , 2 3 0 ) 1 4 1 ( 1 ) ( 2 4 , 1 4 2 ) 3 , 1 3 8 ( 1 3 ) ( 4 7 , 3 7 2 ) 3 , 2 7 9 ( 7 ) 33 3 . 0 0 T U R B I N E S A N D G E N E R A T O R S (3 0 , 6 5 7 , 8 5 6 ) 1 8 6 , 0 8 4 ( 1 ) ( 1 0 , 4 7 6 , 6 1 2 ) 1 , 3 6 1 , 9 5 9 ( 1 3 ) ( 4 1 , 1 3 4 , 4 6 8 ) 1 , 5 4 8 , 0 4 4 ( 4 ) 33 4 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (7 , 4 3 1 , 8 8 7 ) 4 5 , 1 0 9 ( 1 ) ( 1 1 , 1 4 8 , 5 6 2 ) 1 , 4 4 9 , 3 1 3 ( 1 3 ) ( 1 8 , 5 8 0 , 4 4 9 ) 1 , 4 9 4 , 4 2 3 ( 8 ) 33 5 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T ( 7 3 7 , 1 0 7 ) 4 , 4 7 4 ( 1 ) ( 2 8 5 , 0 4 4 ) 3 7 , 0 5 6 ( 1 3 ) ( 1 , 0 2 2 , 1 5 1 ) 4 1 , 5 3 0 ( 4 ) 33 5 . 2 0 M I S C E L L A N E O U S E Q U I P M E N T - R E C R E A T I O N ( 1 4 , 2 0 9 ) 86 ( 1 ) ( 4 , 5 3 3 ) 5 8 9 ( 1 3 ) ( 1 8 , 7 4 1 ) 6 7 5 ( 4 ) 33 6 . 0 0 R O A D S , R A I L R O A D S A N D B R I D G E S (2 3 0 , 2 4 7 ) 1 , 3 9 8 ( 1 ) ( 3 6 4 , 6 2 3 ) 4 7 , 4 0 1 ( 1 3 ) ( 5 9 4 , 8 7 0 ) 4 8 , 7 9 9 ( 8 ) T O T A L N I N E M I L E (8 4 , 1 5 8 , 3 4 7 ) 5 1 0 , 8 1 7 ( 1 ) ( 2 8 , 5 4 5 , 7 7 9 ) 3 , 7 1 0 , 9 5 1 ( 1 3 ) ( 1 1 2 , 7 0 4 , 1 2 6 ) 4 , 2 2 1 , 7 6 8 ( 4 ) PO S T F A L L S 33 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (6 , 0 3 0 , 8 9 8 ) 7 5 , 9 0 3 ( 1 ) ( 7 2 0 , 7 6 8 ) 9 3 , 7 0 0 ( 1 3 ) ( 6 , 7 5 1 , 6 6 6 ) 1 6 9 , 6 0 3 ( 3 ) 33 1 . 1 0 S T R U C T U R E S A N D I M P R O V E M E N T S - FIS H A N D W I L D L I F E C O N S E R V A T I O N ( 4 , 0 4 8 ) 5 1 ( 1 ) ( 2 , 1 3 3 ) 2 7 7 ( 1 3 ) ( 6 , 1 8 1 ) 3 2 8 ( 5 ) 33 1 . 2 0 S T R U C T U R E S A N D I M P R O V E M E N T S - R E C R E A T I O N (5 7 3 , 3 5 1 ) 7,2 1 6 (1) (3 2 7 , 8 2 8 ) 42 , 6 1 8 (1 3 ) (9 0 1 , 1 7 9 ) 49 , 8 3 4 (6 ) 33 2 . 0 0 R E S E R V O I R S , D A M S A N D W A T E R W A Y S (2 1 , 1 3 7 , 2 3 8 ) 26 6 , 0 2 6 (1 ) (3 , 2 1 8 , 6 3 2 ) 41 8 , 4 2 2 (1 3 ) (2 4 , 3 5 5 , 8 7 0 ) 68 4 , 4 4 9 (3 ) 33 2 . 1 0 R E S E R V O I R S , D A M S A N D W A T E R W A Y S - FIS H A N D W I L D L I F E C O N S E R V A T I O N (1 , 1 0 9 , 0 3 8 ) 13 , 9 5 8 (1 ) (2 6 0 , 2 0 9 ) 33 , 8 2 7 (1 3 ) (1 , 3 6 9 , 2 4 8 ) 47 , 7 8 5 (3 ) 33 2 . 2 0 R E S E R V O I R S , D A M S A N D WA T E R W A Y S - R E C R E A T I O N (1 9 8 , 4 4 5 ) 2,4 9 8 (1 ) (1 4 0 , 4 2 6 ) 18 , 2 5 5 (1 3 ) (3 3 8 , 8 7 0 ) 20 , 7 5 3 (6 ) 33 3 . 0 0 T U R B I N E S A N D G E N E R A T O R S (1 , 0 4 4 , 2 1 2 ) 13 , 1 4 2 (1 ) (1 , 1 8 9 , 4 3 9 ) 15 4 , 6 2 7 (1 3 ) (2 , 2 3 3 , 65 1 ) 16 7 , 7 6 9 (8 ) 33 4 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (8 6 5 , 2 7 2 ) 10 , 8 9 0 (1 ) (1 , 5 8 3 , 0 0 2 ) 20 5 , 7 9 0 (1 3 ) (2 , 4 4 8 , 2 7 4 ) 21 6 , 6 8 0 (9 ) 33 5 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T (5 8 7 , 7 9 3 ) 7,3 9 8 (1 ) (2 2 1 , 5 4 7 ) 28 , 8 0 1 (1 3 ) (8 0 9 , 3 4 0 ) 36 , 1 9 9 (4 ) 33 5 . 1 5 M I S C E L L A N E O U S E Q U I P M E N T - F I SH A N D W I L D L I F E C O N S E R V A T I O N (1 4 , 2 7 6 ) 18 0 (1 ) (2 , 6 4 9 ) 34 4 (1 3 ) (1 6 , 9 2 5 ) 52 4 (3 ) 33 6 . 0 0 R O A D S , R A I L R O A D S A N D B R I D G E S (4 8 8 , 8 6 1 ) 6,1 5 3 (1 ) (8 9 , 0 8 3 ) 11 , 5 8 1 (1 3 ) (5 7 7 , 9 4 4 ) 17 , 7 3 3 (3 ) T O T A L P O S T F A L L S (3 1 , 5 5 0 , 2 9 5 ) 39 7 , 0 8 2 (1 ) (7 , 7 5 5 , 7 1 5 ) 1,0 0 8 , 2 4 3 (1 3 ) (3 9 , 8 0 9 , 1 4 8 ) 1,4 1 1 , 6 5 7 (4 ) CA B I N E T G O R G E 33 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (1 8 , 2 2 6 , 3 5 4 ) 2,2 3 0 , 2 3 7 (1 2 ) (5 , 2 0 8 , 5 1 5 ) 67 7 , 1 0 7 (1 3 ) (2 3 , 4 3 4 , 8 6 9 ) 2,9 0 7 , 3 4 4 (1 2 ) 33 1 . 1 0 S T R U C T U R E S A N D I M P R O V E M E N T S - FIS H A N D W I L D L I F E C O N S E R V A T I O N (9 , 7 7 4 ) 1,1 9 6 (1 2 ) (2 1 , 8 7 6 ) 2,8 4 4 (1 3 ) (3 1 , 6 5 0 ) 4,0 4 0 (1 3 ) 33 1 . 2 0 S T R U C T U R E S A N D I M P R O V E M E N T S - R E C R E A T I O N (8 7 0 , 5 8 5 ) 10 6 , 5 2 8 (1 2 ) (1 , 4 8 3 , 4 5 7 ) 19 2 , 8 4 9 (1 3 ) (2 , 3 5 4 , 0 4 2 ) 29 9 , 3 7 7 (1 3 ) 33 1 . 2 6 S T R U C T U R E S A N D I M P R O V E M E N T S - R E C R E A T I O N I N F O R M A T I O N A N D E D U C A T I O N (8 , 7 6 4 ) 1,0 7 2 (1 2 ) (2 9 , 1 4 7 ) 3,7 8 9 (1 3 ) (3 7 , 9 1 1 ) 4,8 6 1 (1 3 ) 33 2 . 0 0 R ES E R V O I R S , D A M S A N D W A T E R W A Y S (1 8 , 7 0 3 , 1 4 0 ) 2,2 8 8 , 5 7 8 (1 2 ) (8 , 1 3 7 , 8 2 2 ) 1,0 5 7 , 9 1 7 (1 3 ) (2 6 , 8 4 0 , 9 6 2 ) 3,3 4 6 , 4 9 5 (1 2 ) 33 2 . 1 0 RE S E R V O I R S , D A M S A N D W A T E R W A Y S - FIS H A N D W I L D L I F E C O N S E R V A T I O N (8 , 4 1 6 , 3 0 8 ) 1,0 2 9 , 8 4 7 (1 2 ) (7 , 9 3 7 , 2 0 4 ) 1,0 3 1 , 8 3 6 (1 3 ) (1 6 , 3 5 3 , 5 1 1 ) 2,0 6 1 , 6 8 4 (1 3 ) 33 2 . 1 5 R E S E R V O I R S , D A M S A N D W A T E R W A Y S - FIS H A N D W I L D L I F E C O N S E R V A T I O N (8 0 4 , 0 1 1 ) 98 , 3 8 1 (1 2 ) (6 9 0 , 6 5 0 ) 89 , 7 8 5 (1 3 ) (1 , 4 9 4 , 6 6 1 ) 18 8 , 1 6 6 (1 3 ) 33 2 . 2 0 R E S E R V O I R S , D A M S A N D WA T E R W A Y S - R E C R E A T I O N (2 8 , 3 1 2 ) 3,4 6 4 (1 2 ) (7 4 , 2 5 9 ) 9,6 5 4 (1 3 ) (1 0 2 , 5 7 0 ) 13 , 1 1 8 (1 3 ) 33 3 . 0 0 T U R B I N E S A N D G E N E R A T O R S (2 4 , 7 0 6 , 6 4 9 ) 3,0 2 3 , 1 8 7 (1 2 ) (2 2 , 1 6 3 , 3 1 3 ) 2,8 8 1 , 2 3 1 (1 3 ) (4 6 , 8 6 9 , 9 6 3 ) 5,9 0 4 , 4 1 8 (1 3 ) 33 4 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (3 , 5 3 1 , 3 2 5 ) 43 2 , 1 0 5 (1 2 ) (1 3 , 8 5 0 , 9 7 5 ) 1,8 0 0 , 6 2 7 (1 3 ) (1 7 , 3 8 2 , 3 0 0 ) 2,2 3 2 , 7 3 1 (1 3 ) 33 5 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T (2 , 7 1 1 , 8 7 9 ) 33 1 , 8 3 4 (1 2 ) (2 , 6 0 8 , 1 5 6 ) 33 9 , 0 6 0 (1 3 ) (5 , 3 2 0 , 0 3 5 ) 67 0 , 8 9 5 (1 3 ) 33 5 . 1 0 M I S C E L L A N E O U S E Q U I P M E N T - F I SH A N D W I L D L I F E C O N S E R V A T I O N (2 7 , 5 3 9 ) 3,3 7 0 (1 2 ) (8 9 , 8 9 7 ) 11 , 6 8 7 (1 3 ) (1 1 7 , 4 3 6 ) 15 , 0 5 6 (1 3 ) 33 5 . 1 5 M I S C E L L A N E O U S E Q U I P M E N T - F I S H A N D W I L D L I F E C O N S E R V A T I O N (1 4 7 , 8 9 1 ) 18 , 0 9 6 (1 2 ) (9 8 , 8 1 7 ) 12 , 8 4 6 (1 3 ) (2 4 6 , 7 0 8 ) 30 , 9 4 3 (1 3 ) 33 5 . 2 0 M I S C E L L A N E O U S E Q U I P M E N T - R E C R E A T I O N (2 0 , 9 1 5 ) 2,5 5 9 (1 2 ) (2 8 , 39 3 ) 3,6 9 1 (1 3 ) (4 9 , 3 0 8 ) 6,2 5 0 (1 3 ) 33 6 . 0 0 R O A D S , R A I L R O A D S A N D B R I D G E S (3 8 7 , 6 5 4 ) 47 , 4 3 5 (1 2 ) (1 , 2 8 3 , 3 5 9 ) 16 6 , 8 3 7 (1 3 ) (1 , 6 7 1 , 0 1 3 ) 21 4 , 2 7 1 (1 3 ) T O T A L C A B I N E T G O R G E (7 8 , 6 0 1 , 0 9 9 ) 9,6 1 7 , 8 8 9 (1 2 ) (6 3 , 7 0 5 , 8 4 0 ) 8,2 8 1 , 7 5 9 (1 3 ) (1 4 2 , 3 0 6 , 9 3 9 ) 17 , 8 9 9 , 6 4 8 (1 3 ) _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-4 Attachment C J. Spanos, Avista Page 364 of 800 AV I S T A C O R P O R A T I O N CA L C U L A T I O N O F W E I G H T E D N E T S A L V A G E P E R C E N T F O R G E N E R A T I O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 TE R M I N A L R E T I R E M E N T S I N T E R I M R E T I R E M E N T S NE T N E T N E T N E T T O T A L E S T I M A T E D SA L V A G E S A L V A G E SA L V A G E S A L V A G E TO T A L N E T NE T AC C O U N T RE T I R E M E N T S AM O U N T PE R C E N T R E T I R E M E N T S AM O U N T PE R C E N T R E T I R E M E N T S S A L V A G E SA L V A G E (1 ) (2 ) (3 ) (4 ) = ( 3 ) / ( 2 ) (5 ) (6 ) = ( 5 ) * ( 7 ) (7 ) (8 ) = ( 2 ) + ( 5 ) (9 ) = ( 3 ) + ( 6 ) (1 0 ) = ( 9 ) / ( 8 ) NO X O N R A P I D S 33 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (1 5 , 5 7 1 , 8 0 6 ) 4 , 5 6 9 , 9 0 8 ( 2 9 ) ( 5 , 9 1 5 , 9 5 3 ) 7 6 9 , 0 7 4 ( 1 3 ) ( 2 1 , 4 8 7 , 7 6 0 ) 5 , 3 3 8 , 9 8 2 ( 2 5 ) 33 1 . 1 0 S T R U C T U R E S A N D I M P R O V E M E N T S - F I SH A N D W I L D L I F E C O N S E R V A T I O N ( 2 9 9 , 5 8 0 ) 8 7 , 9 1 9 ( 2 9 ) ( 7 9 0 , 5 4 1 ) 1 0 2 , 7 7 0 ( 1 3 ) ( 1 , 0 9 0 , 1 2 1 ) 1 9 0 , 6 8 9 ( 1 7 ) 33 1 . 2 0 S T R U C T U R E S A N D I M P R O VE M E N T S - R E C R E A T I O N ( 4 2 3 , 6 4 2 ) 1 2 4 , 3 2 8 ( 2 9 ) ( 1 , 9 0 8 , 6 6 8 ) 2 4 8 , 1 2 7 ( 1 3 ) ( 2 , 3 3 2 , 3 1 0 ) 3 7 2 , 4 5 4 ( 1 6 ) 33 1 . 2 6 S T R U C T U R E S A N D I M P R O V E M E N T S - R E C R E A T I O N I N F O R M A T I O N A N D E D U C A T I O N ( 8 5 2 ) 2 5 0 ( 2 9 ) ( 1 2 , 7 5 3 ) 1 , 6 5 8 ( 1 3 ) ( 1 3 , 6 0 6 ) 1 , 9 0 8 ( 1 4 ) 33 2 . 0 0 R E S E R V O I R S , D A M S A N D W A T E R W A Y S ( 1 9 , 9 4 0 , 5 1 4 ) 5 , 8 5 2 , 0 0 7 ( 2 9 ) ( 1 2 , 6 5 9 , 8 0 4 ) 1 , 6 4 5 , 7 7 5 ( 1 3 ) ( 3 2 , 6 0 0 , 3 1 8 ) 7 , 4 9 7 , 7 8 2 ( 2 3 ) 33 2 . 1 0 R E S E R V O I R S , D A M S A N D W A T E R W A Y S - FIS H A N D W I L D L I F E C O N S E R V A T I O N ( 8 9 8 , 2 8 9 ) 2 6 3 , 6 2 4 ( 2 9 ) ( 1 , 4 3 4 , 9 3 7 ) 1 8 6 , 5 4 2 ( 1 3 ) ( 2 , 3 3 3 , 2 2 5 ) 4 5 0 , 1 6 5 ( 1 9 ) 33 2 . 1 5 R E S E R V O I R S , D A M S A N D W A T E R W A Y S - FIS H A N D W I L D L I F E C O N S E R V A T I O N ( 4 1 7 , 2 9 5 ) 1 2 2 , 4 6 5 ( 2 9 ) ( 5 3 8 , 8 8 3 ) 7 0 , 0 5 5 ( 1 3 ) ( 9 5 6 , 1 7 9 ) 1 9 2 , 5 2 0 ( 2 0 ) 33 2 . 2 0 R E S E R V O I R S , D A M S A N D WA T E R W A Y S - R E C R E A T I O N ( 1 3 , 9 7 2 ) 4 , 1 0 0 ( 2 9 ) ( 5 3 , 0 9 7 ) 6 , 9 0 3 ( 1 3 ) ( 6 7 , 0 6 9 ) 1 1 , 0 0 3 ( 1 6 ) 33 3 . 0 0 T U R B I N E S A N D G E N E R A T O R S (3 9 , 9 5 1 , 5 8 7 ) 1 1 , 7 2 4 , 7 2 1 ( 2 9 ) ( 4 8 , 8 7 0 , 7 4 3 ) 6 , 3 5 3 , 1 9 7 ( 1 3 ) ( 8 8 , 8 2 2 , 3 3 0 ) 1 8 , 0 7 7 , 9 1 8 ( 2 0 ) 33 4 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (1 , 2 1 6 , 4 8 7 ) 35 7 , 0 0 6 ( 2 9 ) ( 1 8 , 39 9 , 2 7 4 ) 2 , 3 9 1 , 9 0 6 ( 1 3 ) ( 1 9 , 6 1 5 , 7 6 1 ) 2 , 7 4 8 , 9 1 2 ( 1 4 ) 33 5 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T ( 1 , 2 4 8 , 7 4 2 ) 3 6 6 , 4 7 2 ( 2 9 ) ( 2 , 1 0 4 , 5 7 0 ) 2 7 3 , 5 9 4 ( 1 3 ) ( 3 , 3 5 3 , 3 1 2 ) 6 4 0 , 0 6 6 ( 1 9 ) 33 5 . 1 0 M I S C E L L A N E O U S E Q U I P M E N T - F I S H A N D W I L D L I F E C O N S E R V A T I O N ( 1 5 , 8 8 6 ) 4 , 6 6 2 ( 2 9 ) ( 3 4 0 , 0 9 4 ) 4 4 , 2 1 2 ( 1 3 ) ( 3 5 5 , 9 8 0 ) 4 8 , 8 7 4 ( 1 4 ) 33 5 . 1 5 M I S C E L L A N E O U S E Q U I P M E N T - F I S H A N D W I L D L I F E C O N S E R V A T I O N ( 2 0 9 , 6 3 0 ) 6 1 , 5 2 1 ( 2 9 ) ( 3 6 9 , 0 0 0 ) 4 7 , 9 7 0 ( 1 3 ) ( 5 7 8 , 6 3 0 ) 1 0 9 , 4 9 1 ( 1 9 ) 33 5 . 2 0 M I S C E L L A N E O U S E Q U I P M E N T - R E C R E A T I O N ( 1 1 , 4 9 7 ) 3 , 3 7 4 ( 2 9 ) ( 3 3 , 8 9 1 ) 4 , 4 0 6 ( 1 3 ) ( 4 5 , 3 8 8 ) 7 , 7 8 0 ( 1 7 ) 33 6 . 0 0 R O A D S , R A I L R O A D S A N D B R I D G E S (3 3 , 1 7 2 ) 9,7 3 5 (2 9 ) (2 2 6 , 5 7 8 ) 29 , 4 5 5 (1 3 ) (2 5 9 , 7 5 0 ) 39 , 1 9 0 (1 5 ) T OT A L N O X O N R A P I D S (8 0 , 2 5 2 , 9 5 1 ) 23 , 5 5 2 , 0 9 3 (2 9 ) (9 3 , 6 5 8 , 7 8 7 ) 12 , 1 7 5 , 6 4 2 (1 3 ) (1 7 3 , 9 1 1 , 7 3 8 ) 35 , 7 2 7 , 7 3 5 (2 1 ) TO T A L H Y D R O P R O D U C T I O N P L A N T (4 0 0 , 7 4 2 , 4 5 6 ) 3 7 , 8 2 7 , 1 7 1 ( 9 ) ( 2 4 6 , 8 6 0 , 9 0 2 ) 3 2 , 0 9 1 , 9 1 7 ( 1 3 ) ( 6 4 7 , 6 0 3 , 3 5 9 ) 6 9 , 9 1 9 , 0 8 8 ( 1 1 ) OT H E R P R O D U C T I O N P L A N T KE T T L E F A L L S 34 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (8 , 9 8 5 ) 1 1 0 ( 1 ) ( 4 4 ) 0 ( 1 ) ( 9 , 0 2 9 ) 1 1 0 ( 1 ) 34 2 . 0 0 F U E L H O L D E R S (8 0 , 9 5 2 ) 9 8 7 ( 1 ) ( 8 , 2 8 0 ) 8 3 (1 ) ( 8 9 , 2 3 2 ) 1 , 0 6 9 ( 1 ) 34 3 . 0 0 P R I M E M O V E R S (7 , 8 7 1 , 7 2 4 ) 9 5 , 9 3 6 ( 1 ) ( 7 9 8 , 3 6 1 ) 7 , 9 8 4 ( 1 ) ( 8 , 6 7 0 , 0 8 4 ) 1 0 3 , 9 2 0 ( 1 ) 34 4 . 0 0 G E N E R A T O R S (2 0 8 , 4 1 9 ) 2 , 5 4 0 ( 1 ) ( 2 5 , 8 4 2 ) 2 5 8 ( 1 ) ( 2 3 4 , 2 6 1 ) 2 , 7 9 9 ( 1 ) 34 5 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (4 4 4 , 6 9 9 ) 5 , 4 2 0 ( 1 ) ( 9 3 , 8 2 4 ) 9 3 8 ( 1 ) ( 5 3 8 , 5 2 3 ) 6 , 3 5 8 ( 1 ) T O T A L K E T T L E F A L L S (8 , 6 1 4 , 7 7 9 ) 1 0 4 , 9 9 2 ( 1 ) ( 9 2 6 , 3 5 0 ) 9 , 2 6 3 ( 1 ) ( 9 , 5 4 1 , 1 2 9 ) 1 1 4 , 2 5 5 ( 1 ) NO R T H E A S T T U R B I N E 34 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (6 4 4 , 2 6 1 ) 5 4 , 0 5 3 ( 8 ) ( 1 0 6 , 7 6 4 ) 1 , 0 6 8 ( 1 ) ( 7 5 1 , 0 2 5 ) 5 5 , 1 2 0 ( 7 ) 34 2 . 0 0 F U E L H O L D E R S (3 3 , 0 2 2 ) 2 , 7 7 0 ( 8 ) ( 3 , 8 7 5 ) 3 9 ( 1 ) ( 3 6 , 8 9 7 ) 2 , 8 0 9 ( 8 ) 34 3 . 0 0 P R I M E M O V E R S (7 , 0 9 2 , 9 9 4 ) 5 9 5 , 0 9 3 ( 8 ) ( 1 , 9 6 5 , 2 8 1 ) 1 9 , 6 5 3 ( 1 ) ( 9 , 0 5 8 , 2 7 4 ) 6 1 4 , 7 4 6 ( 7 ) 34 4 . 0 0 G E N E R A T O R S (2 , 0 5 4 , 3 4 7 ) 1 7 2 , 3 5 7 ( 8 ) ( 8 0 2 , 3 2 0 ) 8 , 0 2 3 ( 1 ) ( 2 , 8 5 6 , 6 6 7 ) 1 8 0 , 3 8 0 ( 6 ) 34 5 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (8 7 4 , 3 0 7 ) 7 3 , 3 5 3 ( 8 ) ( 3 6 8 , 7 5 4 ) 3 , 6 8 8 ( 1 ) ( 1 , 2 4 3 , 0 6 1 ) 7 7 , 0 4 1 (6 ) 34 6 . 0 0 M IS C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T ( 2 1 4 , 3 0 7 ) 1 7 , 9 8 0 ( 8 ) ( 1 8 4 , 6 9 1 ) 1 , 8 4 7 ( 1 ) ( 3 9 8 , 9 9 7 ) 1 9 , 8 2 7 ( 5 ) T O T A L N O R T H E A S T T U R B I N E (1 0 , 9 1 3 , 2 3 7 ) 9 1 5 , 6 0 7 ( 8 ) ( 3 , 4 3 1 , 6 8 5 ) 3 4 , 3 1 7 ( 1 ) ( 1 4 , 3 4 4 , 9 2 2 ) 9 4 9 , 9 2 4 ( 7 ) BO U L D E R P A R K 34 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (1 , 1 8 8 , 1 6 0 ) 18 , 1 7 8 (2 ) (85 , 7 3 2 ) 85 7 (1 ) (1 , 2 7 3 , 8 9 2 ) 19 , 0 3 5 (1 ) 34 2 . 0 0 F U E L H O L D E R S (1 5 4 , 5 8 1 ) 2,3 6 5 (2 ) (7 , 5 6 2 ) 76 (1 ) (1 6 2 , 1 4 3 ) 2,4 4 1 (2 ) 34 3 . 0 0 P R I M E M O V E R S (5 0 , 6 3 4 ) 77 5 (2 ) (6 , 5 8 2 ) 66 (1 ) (5 7 , 2 1 6 ) 84 0 (1 ) 34 4 . 0 0 G E N E R A T O R S (2 4 , 3 3 1 , 1 8 5 ) 37 2 , 2 5 3 (2 ) (7 , 0 3 9 , 2 7 4 ) 70 , 3 9 3 (1 ) (3 1 , 3 7 0 , 4 5 9 ) 44 2 , 6 4 6 (1 ) 34 4 . 0 1 G E N E R A T O R S - S O L A R (1 0 , 6 3 3 ) 16 3 (2 ) (1 1 , 8 4 9 ) 11 8 (1 ) (2 2 , 4 8 2 ) 28 1 (1 ) 34 5 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (5 6 0 , 0 9 0 ) 8,5 6 9 (2 ) (3 6 4 , 7 1 3 ) 3,6 4 7 (1 ) (9 2 4 , 8 0 3 ) 12 , 2 1 6 (1 ) 34 6 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T (5 2 , 1 0 6 ) 79 7 (2 ) (1 2 , 5 4 7 ) 12 5 (1 ) (6 4 , 6 5 2 ) 92 3 (1 ) T O T A L B O U L D E R P A R K (2 6 , 3 4 7 , 3 9 0 ) 40 3 , 1 0 0 (2 ) (7 , 5 2 8 , 25 8 ) 75 , 2 8 3 (1 ) (3 3 , 8 7 5 , 6 4 8 ) 47 8 , 3 8 3 (1 ) _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-5 Attachment C J. Spanos, Avista Page 365 of 800 AV I S T A C O R P O R A T I O N CA L C U L A T I O N O F W E I G H T E D N E T S A L V A G E P E R C E N T F O R G E N E R A T I O N P L A N T A S O F D E C E M B E R 3 1 , 2 0 2 1 TE R M I N A L R E T I R E M E N T S I N T E R I M R E T I R E M E N T S NE T N E T N E T N E T T O T A L E S T I M A T E D SA L V A G E S A L V A G E SA L V A G E S A L V A G E TO T A L N E T NE T AC C O U N T RE T I R E M E N T S AM O U N T PE R C E N T R E T I R E M E N T S AM O U N T PE R C E N T R E T I R E M E N T S S A L V A G E SA L V A G E (1 ) (2 ) (3 ) (4 ) = ( 3 ) / ( 2 ) (5 ) (6 ) = ( 5 ) * ( 7 ) (7 ) (8 ) = ( 2 ) + ( 5 ) (9 ) = ( 3 ) + ( 6 ) (1 0 ) = ( 9 ) / ( 8 ) RA T H D R U M T U R B I N E 34 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (3 , 5 1 8 , 4 1 1 ) 1 3 9 , 0 2 9 ( 4 ) ( 6 6 , 0 9 1 ) 6 6 1 ( 1 ) ( 3 , 5 8 4 , 5 0 2 ) 1 3 9 , 6 9 0 ( 4 ) 34 2 . 0 0 F U E L H O L D E R S (1 , 6 1 8 , 2 5 5 ) 6 3 , 9 4 5 ( 4 ) ( 7 7 , 5 5 3 ) 7 7 6 ( 1 ) ( 1 , 6 9 5 , 8 0 8 ) 6 4 , 7 2 1 ( 4 ) 34 3 . 0 0 P R I M E M O V E R S (3 , 4 5 1 , 3 2 6 ) 1 3 6 , 3 7 9 ( 4 ) ( 2 0 7 , 0 0 2 ) 2 , 0 7 0 ( 1 ) ( 3 , 6 5 8 , 3 2 8 ) 1 3 8 , 4 4 9 ( 4 ) 34 4 . 0 0 G E N E R A T O R S (4 5 , 4 6 4 , 4 3 4 ) 1 , 7 9 6 , 5 1 9 ( 4 ) ( 5 , 7 3 8 , 0 3 8 ) 5 7 , 3 8 0 ( 1 ) ( 5 1 , 2 0 2 , 4 7 2 ) 1 , 8 5 3 , 8 9 9 ( 4 ) 34 5 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (3 , 8 0 7 , 8 8 3 ) 1 5 0 , 4 6 8 ( 4 ) ( 1 , 0 0 0 , 1 8 7 ) 1 0 , 0 0 2 ( 1 ) ( 4 , 8 0 8 , 0 7 0 ) 1 6 0 , 4 7 0 ( 3 ) 34 6 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T ( 2 2 4 , 7 7 0 ) 8 , 8 8 2 ( 4 ) ( 2 4 , 7 0 2 ) 2 4 7 ( 1 ) ( 2 4 9 , 4 7 2 ) 9 , 1 2 9 ( 4 ) T O T A L R A T H D R U M T U R B I N E (5 8 , 0 8 5 , 0 8 0 ) 2 , 2 9 5 , 2 2 1 ( 4 ) ( 7 , 1 1 3 , 5 7 3 ) 7 1 , 1 3 6 ( 1 ) ( 6 5 , 1 9 8 , 6 5 3 ) 2 , 3 6 6 , 3 5 7 ( 4 ) LA N C A S T E R 34 2 . 0 0 F U E L H O L D E R S (8 6 , 4 6 8 ) 2 , 7 7 9 ( 3 ) ( 5 , 5 1 0 ) 5 5 ( 1 ) ( 9 1 , 9 7 8 ) 2 , 8 3 4 ( 3 ) 34 4 . 0 0 G E N E R A T O R S (1 7 5 , 5 7 1 ) 5 , 6 4 2 ( 3 ) ( 3 2 , 9 3 5 ) 3 2 9 ( 1 ) ( 2 0 8 , 5 0 6 ) 5 , 9 7 1 ( 3 ) 34 5 . 0 0 A C C E S S O R Y E L EC T R I C E Q U I P M E N T (2 3 5 , 4 7 9 ) 7,5 6 7 (3 ) (7 2 , 60 2 ) 72 6 (1 ) (3 0 8 , 0 8 0 ) 8,2 9 3 (3 ) T O T A L L A N C A S T E R (4 9 7 , 5 1 8 ) 15 , 9 8 7 (3 ) (1 1 1 , 0 4 7 ) 1,1 1 0 (1 ) (6 0 8 , 5 6 4 ) 17 , 0 9 7 (3 ) CO Y O T E S P R I N G S 2 34 1 . 0 0 S T R U C T U R E S A N D I M P R O V E M E N T S (1 0 , 7 4 2 , 7 5 9 ) 33 4 , 2 4 5 (3 ) (1 , 0 1 5 , 1 6 6 ) 10 , 1 5 2 (1 ) (1 1 , 7 5 7 , 9 2 5 ) 34 4 , 3 9 7 (3 ) 34 2 . 0 0 F U E L H O L D E R S (1 6 , 4 9 3 , 0 9 3 ) 51 3 , 1 5 8 (3 ) (2 , 5 0 7 , 1 9 7 ) 25 , 0 7 2 (1 ) (1 9 , 0 0 0 , 2 8 9 ) 53 8 , 2 3 0 (3 ) 34 4 . 0 0 G E N E R A T O R S (1 2 2 , 0 7 4 , 9 0 1 ) 3,7 9 8 , 1 7 9 (3 ) (3 1 , 8 4 0 , 9 5 3 ) 31 8 , 4 1 0 (1 ) (1 5 3 , 9 1 5 , 8 5 4 ) 4,1 1 6 , 5 8 9 (3 ) 34 5 . 0 0 AC C E S S O R Y E L EC T R I C E Q U I P M E N T (7 , 5 4 2 , 4 6 8 ) 23 4 , 6 7 3 (3 ) (1 0 , 3 4 3 , 9 0 4 ) 10 3 , 4 3 9 (1 ) (1 7 , 8 8 6 , 3 7 2 ) 33 8 , 1 1 2 (2 ) 34 6 . 0 0 M I S C E L L A N E O U S P O W E R P L A N T E Q U I P M E N T (5 1 0 , 8 3 8 ) 15 , 8 9 4 (3 ) (4 2 4 , 3 3 4 ) 4,2 4 3 (1 ) (9 3 5 , 1 7 3 ) 20 , 1 3 7 (2 ) T O T A L C O Y O T E S P R I N G S 2 (1 5 7 , 3 6 4 , 0 6 0 ) 4,8 9 6 , 1 4 9 (3 ) (4 6 , 1 3 1 , 5 5 3 ) 46 1 , 3 1 6 (1 ) (2 0 3 , 4 9 5 , 6 1 3 ) 5,3 5 7 , 4 6 5 (3 ) CE N T R A L O P E R A T I O N S F A C I L I T Y 34 4 . 0 1 G E N E R A T O R S - S O L A R (4 1 3 , 2 3 3 ) 12 , 1 5 4 (3 ) (3 5 , 9 3 9 ) 0 0 (4 4 9 , 1 7 2 ) 12 , 1 5 4 (3 ) 34 5 . 0 1 A C C E S S O R Y E L E C T R I C E Q U I P M E N T - S O L A R (1 , 0 3 4 ) 30 (3 ) (3 2 , 1 7 6 ) 0 0 ( 33,209) 3 0 0 T O T A L C E N T R A L O P E R A T I O N S F A C I L I T Y (4 1 4 , 2 6 7 ) 12 , 1 8 4 (3 ) (6 8 , 1 1 5 ) 0 0 (4 8 2 , 3 8 2 ) 12 , 1 8 4 (3 ) TO T A L O T H E R P R O D U C T I O N P L A N T (2 6 2 , 2 3 6 , 3 3 1 ) 8 , 6 4 3 , 2 4 0 ( 6 5 , 3 1 0 , 5 7 9 ) 6 5 2 , 4 2 5 ( 1 ) ( 3 2 7 , 5 4 6 , 9 1 1 ) 9 , 2 9 5 , 6 6 5 ( 3 ) TO T A L P R O D U C T I O N P L A N T (1 , 0 6 5 , 3 7 5 , 3 7 5 ) 5 9 , 7 0 1 , 8 6 6 ( 3 5 0 , 7 8 5 , 9 2 9 ) 3 6 , 2 1 9 , 6 4 2 ( 1 0 ) ( 1 , 4 1 6 , 1 6 1 , 3 0 4 ) 9 5 , 9 2 1 , 5 0 8 ( 7 ) _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-6 Attachment C J. Spanos, Avista Page 366 of 800 ELECTRIC PLANT _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-7 Attachment C J. Spanos, Avista Page 367 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 311.00 STRUCTURES AND IMPROVEMENTS SUMMARY OF BOOK SALVAGE 1983 4,142 0 0 0 1984 7,072 0 0 0 1985 69,880 0 0 0 1986 93,718 0 0 0 1987 3,341 0 0 0 1988 84,463 84,463 1989 23,181 7 0 1,239 5 1,232 5 1990 52,136 0 47,404 91 47,404 91 1991 13,450 19,374 5,924 1992 48,983 7,394 41,589 - 1993 741 39,070 38,329 1994 1995 86,172 2,193 3 620 1 1,573 - 2 - 1996 158 74,962 74,804 1997 33,157 4,098 12 19,208 58 15,110 46 1998 70,595 0 18,352 26 18,352 26 1999 58,975 58,975 2000 6,485,945 0 1,054 0 1,054 0 2001 6,834 0 1,209 18 1,209 18 2002 6,361 6,361 2003 8,290- 8,290 - 2004 34,014 0 114- 0 114 - 0 2005 76,964 0 0 0 2006 39,414 19,608 - 50 - 711 2 20,319 52 2007 16,833 6,062 36 0 6,062 - 36 - 2008 228,917 48,870 21 613 0 48,257 - 21 - 2009 41,818 0 0 0 2010 107,595 0 1,656 2 1,656 2 2011 51,777 0 0 0 2012 2,539 1,838 72 0 1,838 - 72 - 2013 120,395 15,430 13 0 15,430 - 13 - 2014 69,920 65,608 94 0 65,608 - 94 - 2015 113,149 183,744 162 0 183,744 - 162 - 2016 69,778 25,079 - 36 - 0 25,079 36 2017 54,316 0 0 0 2018 192,936 0 0 0 2019 31,604 28,158 89 0 28,158 - 89 - 2020 177,410 10,626 6 0 10,626 - 6 - 2021 70,814 785 1 0 785 - 1 - TOTAL 8,436,366 386,064 5 374,260 4 11,803 - 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-8 Attachment C J. Spanos, Avista Page 368 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 311.00 STRUCTURES AND IMPROVEMENTS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 27,031 0 0 0 84-86 56,890 0 0 0 85-87 55,646 0 0 0 86-88 32,353 0 28,154 87 28,154 87 87-89 8,841 2 0 28,567 323 28,565 323 88-90 25,106 2 0 44,369 177 44,366 177 89-91 25,106 4,486 18 22,672 90 18,187 72 90-92 17,379 20,811 120 24,724 142 3,913 23 91-93 21,058 21,946 888 92-94 16,575 15,488 1,087 - 93-95 28,724 978 3 13,230 46 12,252 43 94-96 28,724 784 3 25,194 88 24,410 85 95-97 39,776 2,150 5 31,597 79 29,447 74 96-98 34,584 1,419 4 37,507 108 36,089 104 97-99 34,584 1,366 4 32,178 93 30,812 89 98-00 2,185,513 0 26,127 1 26,127 1 99-01 2,164,260 0 20,413 1 20,413 1 00-02 2,164,260 0 2,875 0 2,875 0 01-03 2,278 0 240 - 11 - 240 - 11 - 02-04 11,338 0 681 - 6 - 681 - 6 - 03-05 36,993 0 2,802 - 8 - 2,802 - 8 - 04-06 50,131 6,536- 13 - 199 0 6,735 13 05-07 44,404 4,515- 10 - 237 1 4,752 11 06-08 95,055 11,775 12 441 0 11,334 - 12 - 07-09 95,856 18,311 19 204 0 18,107 - 19 - 08-10 126,110 16,290 13 756 1 15,534 - 12 - 09-11 67,063 0 552 1 552 1 10-12 53,970 613 1 552 1 60 - 0 11-13 58,237 5,756 10 0 5,756 - 10 - 12-14 64,285 27,625 43 0 27,625 - 43 - 13-15 101,155 88,261 87 0 88,261 - 87 - 14-16 84,282 74,757 89 0 74,757 - 89 - 15-17 79,081 52,888 67 0 52,888 - 67 - 16-18 105,676 8,360- 8 - 0 8,360 8 17-19 92,952 9,386 10 0 9,386 - 10 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-9 Attachment C J. Spanos, Avista Page 369 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 311.00 STRUCTURES AND IMPROVEMENTS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 133,983 12,928 10 0 12,928 - 10 - 19-21 93,276 13,190 14 0 13,190 - 14 - FIVE-YEAR AVERAGE 17-21 105,416 7,914 8 0 7,914 - 8 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-10 Attachment C J. Spanos, Avista Page 370 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 312.00 BOILER PLANT EQUIPMENT SUMMARY OF BOOK SALVAGE 1984 1,113,512 199,830 18 71 0 199,759 - 18 - 1985 142,777 0 0 0 1986 89,403 - 0 0 0 1987 43,408 467 1 8,569 20 8,102 19 1988 1989 30,588 201 1 1,053,297 1,053,096 1990 962,865 1,603 0 59,290 6 57,687 6 1991 164,768 393 0 12 0 381 - 0 1992 36,848 404 1 9,993 27 9,589 26 1993 3,385 1,743 51 13,176 389 11,433 338 1994 1,397 1,397 - 1995 1,203,872 45,839 4 756 0 45,083 - 4 - 1996 68,744 544 1 3,668 5 3,124 5 1997 1,467,740 11,530- 1 - 81,000 6 92,530 6 1998 2,955,970 46,426 2 1,892 0 44,534 - 2 - 1999 39,114 94,452 241 1,378 4 93,074 - 238 - 2000 33,137,906 0 12,602 0 12,602 0 2001 172,181 0 14,459 8 14,459 8 2002 109,349 0 76,049 70 76,049 70 2003 46,601 0 99,115 - 213 - 99,115 - 213 - 2004 2,235,169 0 5,546 - 0 5,546 - 0 2005 332,757 0 0 0 2006 164,154 17,223- 10 - 0 17,223 10 2007 2,211,303 810 0 1,141 0 331 0 2008 378,583 0 0 0 2009 533,406 13,411 3 6,719 1 6,692 - 1 - 2010 382,826 69,760 18 0 69,760 - 18 - 2011 991,803 0 0 0 2012 936,177 18,377 2 0 18,377 - 2 - 2013 1,079,370 154,300 14 0 154,300 - 14 - 2014 2,302,190 655,980 28 0 655,980 - 28 - 2015 3,377,214 1,837,437 54 0 1,837,437 - 54 - 2016 1,320,884 119,038- 9 - 0 119,038 9 2017 3,308,036 0 0 0 2018 1,514,790 12,065 1 0 12,065 - 1 - 2019 1,118,115 178,244 16 0 178,244 - 16 - 2020 467,210 12,564 3 0 12,564 - 3 - 2021 3,622,765 76,543 2 0 76,543 - 2 - TOTAL 67,886,978 3,274,999 5 1,239,412 2 2,035,587 - 3 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-11 Attachment C J. Spanos, Avista Page 371 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 312.00 BOILER PLANT EQUIPMENT SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 84-86 388,962 66,610 17 24 0 66,586 - 17 - 85-87 32,261 156 0 2,856 9 2,701 8 86-88 15,332 - 156 1 - 2,856 19 - 2,701 18 - 87-89 24,665 223 1 353,955 353,733 88-90 331,151 601 0 370,862 112 370,261 112 89-91 386,074 732 0 370,866 96 370,134 96 90-92 388,160 800 0 23,098 6 22,298 6 91-93 68,334 847 1 7,727 11 6,880 10 92-94 13,411 1,181 9 7,723 58 6,542 49 93-95 402,419 16,326 4 4,644 1 11,682 - 3 - 94-96 424,205 15,927 4 1,475 0 14,452 - 3 - 95-97 913,452 11,618 1 28,475 3 16,857 2 96-98 1,497,485 11,813 1 28,853 2 17,040 1 97-99 1,487,608 43,116 3 28,090 2 15,026 - 1 - 98-00 12,044,330 46,959 0 5,291 0 41,668 - 0 99-01 11,116,400 31,484 0 9,480 0 22,004 - 0 00-02 11,139,812 0 34,370 0 34,370 0 01-03 109,377 0 2,869 - 3 - 2,869 - 3 - 02-04 797,040 0 9,537 - 1 - 9,537 - 1 - 03-05 871,509 0 34,887 - 4 - 34,887 - 4 - 04-06 910,693 5,741 - 1 - 1,849 - 0 3,892 0 05-07 902,738 5,471 - 1 - 380 0 5,852 1 06-08 918,013 5,471 - 1 - 380 0 5,852 1 07-09 1,041,097 4,740 0 2,620 0 2,120 - 0 08-10 431,605 27,724 6 2,240 1 25,484 - 6 - 09-11 636,012 27,724 4 2,240 0 25,484 - 4 - 10-12 770,269 29,379 4 0 29,379 - 4 - 11-13 1,002,450 57,559 6 0 57,559 - 6 - 12-14 1,439,246 276,219 19 0 276,219 - 19 - 13-15 2,252,925 882,572 39 0 882,572 - 39 - 14-16 2,333,429 791,460 34 0 791,460 - 34 - 15-17 2,668,711 572,800 21 0 572,800 - 21 - 16-18 2,047,903 35,658 - 2 - 0 35,658 2 17-19 1,980,314 63,437 3 0 63,437 - 3 - 18-20 1,033,372 67,625 7 0 67,625 - 7 - 19-21 1,736,030 89,117 5 0 89,117 - 5 - FIVE-YEAR AVERAGE 17-21 2,006,183 55,883 3 0 55,883 - 3 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-12 Attachment C J. Spanos, Avista Page 372 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 314.00 TURBOGENERATORS SUMMARY OF BOOK SALVAGE 1985 51,399 0 0 0 1986 685 0 0 0 1987 31,036 0 0 0 1988 2,512 8,865 353 0 8,865 - 353 - 1989 30,346 0 0 0 1990 31,774 7,501 24 0 7,501 - 24 - 1991 689,595 0 612 - 0 612 - 0 1992 240 0 1,552 647 1,552 647 1993 174 174 1994 240 0 0 0 1995 528,642 87,247 17 12,375 2 74,872 - 14 - 1996 12,432 30,686 18,254 1997 214,236 2,439 1 3,317 2 878 0 1998 774,524 0 2,310 0 2,310 0 1999 38,984 16,379 42 0 16,379 - 42 - 2000 13,275,061 0 4,016 0 4,016 0 2001 7,015 0 4,608 66 4,608 66 2002 24,236 24,236 2003 31,587 - 31,587 - 2004 2,042,382 0 4,132 - 0 4,132 - 0 2005 547,727 0 0 0 2006 95,446 55,462 58 0 55,462 - 58 - 2007 1,979,267 0 0 0 2008 1,881,953 0 0 0 2009 594,261 9,357 2 0 9,357 - 2 - 2010 2011 1,609,494 0 0 0 2012 22,114 13,783 62 0 13,783 - 62 - 2013 618,104 115,725 19 0 115,725 - 19 - 2014 3,150,633 492,061 16 0 492,061 - 16 - 2015 494,954 1,378,077 278 0 1,378,077 - 278 - 2016 74,050 188,095 - 254 - 0 188,095 254 2017 207,835 0 0 0 2018 311,471 0 0 0 2019 308,718 339,514 110 0 339,514 - 110 - 2020 268,049 0 0 0 2021 12,804 12,804 - TOTAL 29,882,747 2,363,550 8 46,943 0 2,316,607 - 8 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-13 Attachment C J. Spanos, Avista Page 373 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 314.00 TURBOGENERATORS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 85-87 27,707 0 0 0 86-88 11,411 2,955 26 0 2,955 - 26 - 87-89 21,298 2,955 14 0 2,955 - 14 - 88-90 21,544 5,455 25 0 5,455 - 25 - 89-91 250,572 2,500 1 204 - 0 2,704 - 1 - 90-92 240,536 2,500 1 313 0 2,187 - 1 - 91-93 229,945 0 371 0 371 0 92-94 160 0 575 360 575 360 93-95 176,294 29,082 16 4,183 2 24,899 - 14 - 94-96 176,294 33,226 19 14,354 8 18,873 - 11 - 95-97 247,626 34,039 14 15,459 6 18,580 - 8 - 96-98 329,586 4,957 2 12,104 4 7,147 2 97-99 342,581 6,273 2 1,876 1 4,397 - 1 - 98-00 4,696,190 5,460 0 2,109 0 3,351 - 0 99-01 4,440,354 5,460 0 2,875 0 2,585 - 0 00-02 4,427,359 0 10,954 0 10,954 0 01-03 2,338 0 914 - 39 - 914 - 39 - 02-04 680,794 0 3,828 - 1 - 3,828 - 1 - 03-05 863,370 0 11,906 - 1 - 11,906 - 1 - 04-06 895,185 18,487 2 1,377 - 0 19,865 - 2 - 05-07 874,147 18,487 2 0 18,487 - 2 - 06-08 1,318,888 18,487 1 0 18,487 - 1 - 07-09 1,485,160 3,119 0 0 3,119 - 0 08-10 825,405 3,119 0 0 3,119 - 0 09-11 734,585 3,119 0 0 3,119 - 0 10-12 543,869 4,594 1 0 4,594 - 1 - 11-13 749,904 43,169 6 0 43,169 - 6 - 12-14 1,263,617 207,189 16 0 207,189 - 16 - 13-15 1,421,230 661,954 47 0 661,954 - 47 - 14-16 1,239,879 560,681 45 0 560,681 - 45 - 15-17 258,946 396,661 153 0 396,661 - 153 - 16-18 197,785 62,698 - 32 - 0 62,698 32 17-19 276,008 113,171 41 0 113,171 - 41 - 18-20 296,079 113,171 38 0 113,171 - 38 - 19-21 192,256 117,439 61 0 117,439 - 61 - FIVE-YEAR AVERAGE 17-21 219,215 70,464 32 0 70,464 - 32 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-14 Attachment C J. Spanos, Avista Page 374 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 315.00 ACCESSORY ELECTRIC EQUIPMENT SUMMARY OF BOOK SALVAGE 1984 343,349 0 0 0 1985 128,520 0 0 0 1986 65,048 0 0 0 1987 11,774 0 0 0 1988 1989 4,574 0 0 0 1990 1991 277 0 0 0 1992 323 171 53 1,316 407 1,145 354 1993 3,150 3,150 1994 1995 178,274 425 0 225 0 200 - 0 1996 1997 8,768 273 3 840 10 567 6 1998 165,770 0 0 0 1999 2000 2,942,806 0 6 0 6 0 2001 45,745 0 7 0 7 0 2002 36 36 2003 72,809 0 46 - 0 46 - 0 2004 20,844 0 97 - 0 97 - 0 2005 5,425 0 0 0 2006 2007 4,277 0 0 0 2008 59,602 0 0 0 2009 5,784 754 13 3,062 53 2,308 40 2010 2011 9,843 0 0 0 2012 1,601,785 459 0 0 459 - 0 2013 147,793 3,858 3 0 3,858 - 3 - 2014 62,599 16,402 26 0 16,402 - 26 - 2015 141,011 45,936 33 0 45,936 - 33 - 2016 427,895 6,270 - 1 - 0 6,270 1 2017 555,769 133,714 24 0 133,714 - 24 - 2018 9,466 25,567 270 0 25,567 - 270 - 2019 43,756 0 656 1 656 1 2020 280,472 0 0 0 2021 10,276 61,569 599 0 61,569 - 599 - TOTAL 7,354,634 282,858 4 9,154 0 273,703 - 4 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-15 Attachment C J. Spanos, Avista Page 375 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 315.00 ACCESSORY ELECTRIC EQUIPMENT SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 84-86 178,972 0 0 0 85-87 68,447 0 0 0 86-88 25,607 0 0 0 87-89 5,449 0 0 0 88-90 1,525 0 0 0 89-91 1,617 0 0 0 90-92 200 57 28 439 219 382 191 91-93 200 57 28 1,489 744 1,432 716 92-94 108 57 53 1,489 1,432 93-95 59,425 142 0 1,125 2 983 2 94-96 59,425 142 0 75 0 67 - 0 95-97 62,347 233 0 355 1 122 0 96-98 58,179 91 0 280 0 189 0 97-99 58,179 91 0 280 0 189 0 98-00 1,036,192 0 2 0 2 0 99-01 996,184 0 4 0 4 0 00-02 996,184 0 16 0 16 0 01-03 39,518 0 1 - 0 1 - 0 02-04 31,218 0 36 - 0 36 - 0 03-05 33,026 0 48 - 0 48 - 0 04-06 8,756 0 32 - 0 32 - 0 05-07 3,234 0 0 0 06-08 21,293 0 0 0 07-09 23,221 251 1 1,021 4 769 3 08-10 21,795 251 1 1,021 5 769 4 09-11 5,209 251 5 1,021 20 769 15 10-12 537,209 153 0 0 153 - 0 11-13 586,474 1,439 0 0 1,439 - 0 12-14 604,059 6,906 1 0 6,906 - 1 - 13-15 117,134 22,065 19 0 22,065 - 19 - 14-16 210,502 18,689 9 0 18,689 - 9 - 15-17 374,892 57,793 15 0 57,793 - 15 - 16-18 331,043 51,004 15 0 51,004 - 15 - 17-19 202,997 53,094 26 219 0 52,875 - 26 - 18-20 111,231 8,522 8 219 0 8,304 - 7 - 19-21 111,501 20,523 18 219 0 20,304 - 18 - FIVE-YEAR AVERAGE 17-21 179,948 44,170 25 131 0 44,039 - 24 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-16 Attachment C J. Spanos, Avista Page 376 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 316.00 MISCELLANEOUS POWER PLANT EQUIPMENT SUMMARY OF BOOK SALVAGE 1983 313 28 285 - 1984 2,131 15 1 300 14 285 13 1985 10,387 0 23 0 23 0 1986 5,252 0 0 0 1987 32,854 0 0 0 1988 5,406 8,225 152 0 8,225 - 152 - 1989 41,877 0 11,377 27 11,377 27 1990 55,000 0 29,668 54 29,668 54 1991 52 6,199 6,147 1992 32,925 416 1 2,347 7 1,931 6 1993 2,066 2,066 1994 11,384 11,384 1995 6,310 160 3 438 7 278 4 1996 80 4,632 4,552 1997 504,746 4,279 1 851 0 3,428 - 1 - 1998 217,730 - 0 1,950 1 - 1,950 1 - 1999 727 727 2000 711,424 0 1,951 0 1,951 0 2001 107,941 0 2,239 2 2,239 2 2002 4,506 0 11,775 261 11,775 261 2003 15,346 - 15,346 - 2004 1,245 0 15 - 1 - 15 - 1 - 2005 193,402 10,939- 6 - 0 10,939 6 2006 1,218 1,218 - 2007 4,346 2,844- 65 - 0 2,844 65 2008 12,565 12,565 - 2009 15,969 0 0 0 2010 19,580 0 0 0 2011 24,650 0 0 0 2012 2,914 421 14 0 421 - 14 - 2013 2014 10,679 0 0 0 2015 2,657 0 0 0 2016 31,559 0 0 0 2017 120,271 0 0 0 2018 14,312 0 0 0 2019 2020 29,078 0 0 0 2021 TOTAL 1,773,691 13,961 1 72,593 4 58,632 3 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-17 Attachment C J. Spanos, Avista Page 377 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 316.00 MISCELLANEOUS POWER PLANT EQUIPMENT SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 4,173 109 3 117 3 8 0 84-86 5,923 5 0 108 2 103 2 85-87 16,164 0 8 0 8 0 86-88 14,504 2,742 19 0 2,742 - 19 - 87-89 26,712 2,742 10 3,792 14 1,051 4 88-90 34,094 2,742 8 13,682 40 10,940 32 89-91 32,292 17 0 15,748 49 15,731 49 90-92 29,308 156 1 12,738 43 12,582 43 91-93 10,975 156 1 3,537 32 3,381 31 92-94 10,975 139 1 5,266 48 5,127 47 93-95 2,103 53 3 4,629 220 4,576 218 94-96 2,103 80 4 5,485 261 5,405 257 95-97 170,352 1,506 1 1,974 1 467 0 96-98 95,672 1,453 2 2,478 3 1,025 1 97-99 95,672 1,426 1 1,176 1 250 - 0 98-00 164,565 0 1,543 1 1,543 1 99-01 273,122 0 1,639 1 1,639 1 00-02 274,624 0 5,322 2 5,322 2 01-03 37,482 0 444 - 1 - 444 - 1 - 02-04 1,917 0 1,195 - 62 - 1,195 - 62 - 03-05 64,882 3,646- 6 - 5,120 - 8 - 1,474 - 2 - 04-06 64,882 3,240- 5 - 5 - 0 3,235 5 05-07 65,916 4,188- 6 - 0 4,188 6 06-08 1,449 3,646 252 0 3,646 - 252 - 07-09 6,772 3,240 48 0 3,240 - 48 - 08-10 11,850 4,188 35 0 4,188 - 35 - 09-11 20,066 0 0 0 10-12 15,715 140 1 0 140 - 1 - 11-13 9,188 140 2 0 140 - 2 - 12-14 4,531 140 3 0 140 - 3 - 13-15 4,445 0 0 0 14-16 14,965 0 0 0 15-17 51,496 0 0 0 16-18 55,381 0 0 0 17-19 44,861 0 0 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-18 Attachment C J. Spanos, Avista Page 378 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 316.00 MISCELLANEOUS POWER PLANT EQUIPMENT SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 14,463 0 0 0 19-21 9,693 0 0 0 FIVE-YEAR AVERAGE 17-21 32,732 0 0 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-19 Attachment C J. Spanos, Avista Page 379 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS SUMMARY OF BOOK SALVAGE 1983 50 5,849 1,623 4,226 - 1984 102,482 0 7,400 7 7,400 7 1985 5,828 16,790 288 0 16,790 - 288 - 1986 7,600 81 1 0 81 - 1 - 1987 79,302 66 - 0 988 1 1,054 1 1988 14,035 0 6,000 43 6,000 43 1989 35,232 8,350 24 0 8,350 - 24 - 1990 364,393 88,969 24 90- 0 89,059 - 24 - 1991 30,498 41,192 135 213 1 40,979 - 134 - 1992 11,301 10,610 94 1,339 12 9,271 - 82 - 1993 39,028 1,408 4 0 1,408 - 4 - 1994 37,304 4,908 13 0 4,908 - 13 - 1995 22,267 390 2 0 390 - 2 - 1996 46,067 0 15,500 34 15,500 34 1997 30,055 8,599 29 7,390 25 1,209 - 4 - 1998 2,835 0 0 0 1999 61,771 0 24,007 39 24,007 39 2000 3,026 0 36 1 36 1 2001 21,811 0 33 0 33 0 2002 5,774 0 8 0 8 0 2003 64,178 25 0 535 1 510 1 2004 50,947 2,163 4 118 0 2,044 - 4 - 2005 13,165 0 0 0 2006 10,732 5,066 47 0 5,066 - 47 - 2007 15,181 53,096 350 0 53,096 - 350 - 2008 20,909 5,190 25 0 5,190 - 25 - 2009 17,587 31,214 177 0 31,214 - 177 - 2010 189,159 84,811 45 0 84,811 - 45 - 2011 48,984 9,968 20 0 9,968 - 20 - 2012 9,411 3,457 37 0 3,457 - 37 - 2013 150,786 19,288 13 0 19,288 - 13 - 2014 77,677 82,010 106 0 82,010 - 106 - 2015 66,880 229,680 343 0 229,680 - 343 - 2016 1,282,382 161,547 13 40,000 3 121,547 - 9 - 2017 321,708 43,699 14 0 43,699 - 14 - 2018 536,294 146,035 27 43 0 145,993 - 27 - 2019 487,802 30,210 6 1,281 0 28,929 - 6 - 2020 436,439 1,411,573 323 5,815 1 1,405,758 - 322 - 2021 79,300 1,716 2 0 1,716 - 2 - TOTAL 4,800,178 2,507,826 52 112,239 2 2,395,586 - 50 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-20 Attachment C J. Spanos, Avista Page 380 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 36,120 7,546 21 3,008 8 4,539 - 13 - 84-86 38,637 5,624 15 2,467 6 3,157 - 8 - 85-87 30,910 5,602 18 329 1 5,272 - 17 - 86-88 33,646 5 0 2,329 7 2,324 7 87-89 42,856 2,761 6 2,329 5 432 - 1 - 88-90 137,887 32,440 24 1,970 1 30,470 - 22 - 89-91 143,374 46,170 32 41 0 46,129 - 32 - 90-92 135,397 46,924 35 487 0 46,436 - 34 - 91-93 26,942 17,737 66 517 2 17,219 - 64 - 92-94 29,211 5,642 19 446 2 5,196 - 18 - 93-95 32,866 2,235 7 0 2,235 - 7 - 94-96 35,212 1,766 5 5,167 15 3,401 10 95-97 32,796 2,996 9 7,630 23 4,634 14 96-98 26,319 2,866 11 7,630 29 4,764 18 97-99 31,553 2,866 9 10,466 33 7,599 24 98-00 22,544 0 8,014 36 8,014 36 99-01 28,869 0 8,026 28 8,026 28 00-02 10,204 0 26 0 26 0 01-03 30,588 8 0 192 1 184 1 02-04 40,300 729 2 220 1 509 - 1 - 03-05 42,763 729 2 218 1 511 - 1 - 04-06 24,948 2,410 10 39 0 2,370 - 10 - 05-07 13,026 19,387 149 0 19,387 - 149 - 06-08 15,607 21,117 135 0 21,117 - 135 - 07-09 17,892 29,833 167 0 29,833 - 167 - 08-10 75,885 40,405 53 0 40,405 - 53 - 09-11 85,243 41,997 49 0 41,997 - 49 - 10-12 82,518 32,745 40 0 32,745 - 40 - 11-13 69,727 10,904 16 0 10,904 - 16 - 12-14 79,291 34,918 44 0 34,918 - 44 - 13-15 98,448 110,326 112 0 110,326 - 112 - 14-16 475,646 157,746 33 13,333 3 144,412 - 30 - 15-17 556,990 144,975 26 13,333 2 131,642 - 24 - 16-18 713,461 117,094 16 13,348 2 103,746 - 15 - 17-19 448,602 73,315 16 441 0 72,873 - 16 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-21 Attachment C J. Spanos, Avista Page 381 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 486,845 529,273 109 2,380 0 526,893 - 108 - 19-21 334,513 481,166 144 2,365 1 478,801 - 143 - FIVE-YEAR AVERAGE 17-21 372,309 326,647 88 1,428 0 325,219 - 87 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-22 Attachment C J. Spanos, Avista Page 382 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.20 STRUCTURES AND IMPROVEMENTS - RECREATION SUMMARY OF BOOK SALVAGE 2007 14,099 3,677 - 26 - 0 3,677 26 2008 4,454 0 0 0 2009 2010 4,487 0 0 0 2011 16,927 0 0 0 2012 6,994 1,000 14 0 1,000- 14 - 2013 2014 14,202 0 0 0 2015 2016 45,406 0 0 0 2017 2018 2019 35,084 0 0 0 2020 2021 14,922 2,300 15 0 2,300- 15 - TOTAL 156,576 377 - 0 0 377 0 THREE-YEAR MOVING AVERAGES 07-09 6,184 1,226 - 20 - 0 1,226 20 08-10 2,980 0 0 0 09-11 7,138 0 0 0 10-12 9,469 333 4 0 333- 4 - 11-13 7,974 333 4 0 333- 4 - 12-14 7,065 333 5 0 333- 5 - 13-15 4,734 0 0 0 14-16 19,869 0 0 0 15-17 15,135 0 0 0 16-18 15,135 0 0 0 17-19 11,695 0 0 0 18-20 11,695 0 0 0 19-21 16,669 767 5 0 767- 5 - FIVE-YEAR AVERAGE 17-21 10,001 460 5 0 460- 5 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-23 Attachment C J. Spanos, Avista Page 383 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.00 RESERVOIRS, DAMS AND WATERWAYS SUMMARY OF BOOK SALVAGE 1984 29,976 332 1 23,087 77 22,755 76 1985 1986 16,517 0 10,500 64 10,500 64 1987 10,609 0 0 0 1988 394 0 0 0 1989 60,862 0 3,434 6 3,434 6 1990 272,728 63,250 23 2,908 1 60,342 - 22 - 1991 29,284 116 29,168 - 1992 23,783 4,265 18 107 0 4,158 - 17 - 1993 133,899 15,394 11 1,376 1 14,018 - 10 - 1994 181,235 23,847 13 0 23,847 - 13 - 1995 111,998 1,956 2 9,796 9 7,840 7 1996 1997 197,158 0 771 0 771 0 1998 78,289 0 1,284 2 1,284 2 1999 389,689 0 161,800 42 161,800 42 2000 61,913 0 0 0 2001 2002 12,540 0 0 0 2003 2,516 0 0 0 2004 2,790 0 3,830 137 3,830 137 2005 32,921 0 0 0 2006 2007 21,887 0 0 0 2008 59 0 0 0 2009 2010 3,263,452 164 - 0 5,469 0 5,633 0 2011 16,215 0 580 4 580 4 2012 4,594 4,594 - 2013 83,371 38,575 46 0 38,575 - 46 - 2014 76,909 164,020 213 0 164,020 - 213 - 2015 14,799 459,359 0 459,359 - 2016 1,523,641 129,461 8 9,092 1 120,369 - 8 - 2017 208,932 26,615 13 0 26,615 - 13 - 2018 3,945,536 142,069 4 460 0 141,609 - 4 - 2019 1,106,820 234,042 21 4,266 0 229,776 - 21 - 2020 646,301 169 646,132 - 2021 40,142 0 0 0 TOTAL 11,921,580 1,983,200 17 239,045 2 1,744,155 - 15 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-24 Attachment C J. Spanos, Avista Page 384 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.00 RESERVOIRS, DAMS AND WATERWAYS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 84-86 15,498 111 1 11,196 72 11,085 72 85-87 9,042 0 3,500 39 3,500 39 86-88 9,173 0 3,500 38 3,500 38 87-89 23,955 0 1,145 5 1,145 5 88-90 111,328 21,083 19 2,114 2 18,969 - 17 - 89-91 111,197 30,845 28 2,153 2 28,692 - 26 - 90-92 98,837 32,266 33 1,044 1 31,223 - 32 - 91-93 52,561 16,314 31 533 1 15,781 - 30 - 92-94 112,972 14,502 13 494 0 14,008 - 12 - 93-95 142,377 13,732 10 3,724 3 10,008 - 7 - 94-96 97,744 8,601 9 3,265 3 5,336 - 5 - 95-97 103,052 652 1 3,522 3 2,870 3 96-98 91,816 0 685 1 685 1 97-99 221,712 0 54,618 25 54,618 25 98-00 176,630 0 54,361 31 54,361 31 99-01 150,534 0 53,933 36 53,933 36 00-02 24,818 0 0 0 01-03 5,019 0 0 0 02-04 5,949 0 1,277 21 1,277 21 03-05 12,742 0 1,277 10 1,277 10 04-06 11,904 0 1,277 11 1,277 11 05-07 18,269 0 0 0 06-08 7,315 0 0 0 07-09 7,315 0 0 0 08-10 1,087,837 55 - 0 1,823 0 1,878 0 09-11 1,093,222 55 - 0 2,016 0 2,071 0 10-12 1,093,222 1,477 0 2,016 0 540 0 11-13 33,195 14,390 43 193 1 14,196 - 43 - 12-14 53,427 69,063 129 0 69,063 - 129 - 13-15 58,360 220,651 378 0 220,651 - 378 - 14-16 538,450 250,947 47 3,031 1 247,916 - 46 - 15-17 582,457 205,145 35 3,031 1 202,114 - 35 - 16-18 1,892,703 99,382 5 3,184 0 96,198 - 5 - 17-19 1,753,763 134,242 8 1,575 0 132,667 - 8 - 18-20 1,684,119 340,804 20 1,631 0 339,172 - 20 - 19-21 382,321 293,448 77 1,478 0 291,969 - 76 - FIVE-YEAR AVERAGE 17-21 1,060,286 209,805 20 979 0 208,826 - 20 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-25 Attachment C J. Spanos, Avista Page 385 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.20 RESERVOIRS, DAMS AND WATERWAYS - RECREATION SUMMARY OF BOOK SALVAGE 2011 588 0 0 0 2012 2013 2014 2015 1 0 0 0 2016 141,877 0 0 0 2017 2018 61,392 0 0 0 2019 2020 2021 TOTAL 203,858 0 0 0 THREE-YEAR MOVING AVERAGES 11-13 196 0 0 0 12-14 13-15 0 0 0 14-16 47,293 0 0 0 15-17 47,293 0 0 0 16-18 67,756 0 0 0 17-19 20,464 0 0 0 18-20 20,464 0 0 0 19-21 FIVE-YEAR AVERAGE 17-21 12,278 0 0 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-26 Attachment C J. Spanos, Avista Page 386 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 333.00 TURBINES AND GENERATORS SUMMARY OF BOOK SALVAGE 1984 348,240 4,821 1 110 0 4,711 - 1 - 1985 16,268 0 0 0 1986 149 155 6 1987 74,595 0 551 1 551 1 1988 311,867 207 0 72 0 135 - 0 1989 10,761 0 1,471 14 1,471 14 1990 873,817 251,197 29 0 251,197 - 29 - 1991 14,743 109,256 741 4,923 33 104,333 - 708 - 1992 5,000 1,389 28 20,000 400 18,611 372 1993 490,384 97,880 20 7,790 2 90,090 - 18 - 1994 35,516 4,673 13 0 4,673 - 13 - 1995 992,639 17,338 2 12,861 1 4,477 - 0 1996 1997 217,829 0 4,155 2 4,155 2 1998 5,590 0 0 0 1999 154,073 0 62,398 40 62,398 40 2000 70,467 0 216 0 216 0 2001 77,978 0 199 0 199 0 2002 1,181,151 0 46 0 46 0 2003 1,037,351 147 0 3,182 0 3,036 0 2004 924,314 0 0 0 2005 1,068,067 2,531 - 0 0 2,531 0 2006 82,498 5,925 7 0 5,925 - 7 - 2007 1,174,503 470,363 40 0 470,363 - 40 - 2008 406 13,358 - 232 57 13,589 2009 581,864 1,538 0 3,808 1 2,270 0 2010 7,744 5,891 - 76 - 7,585 98 13,476 174 2011 3,845,369 9,085 - 0 7,097 0 16,182 0 2012 266,410 4,100 2 5,846 2 1,747 1 2013 69,886 30,860 44 0 30,860 - 44 - 2014 60,974 131,216 215 0 131,216 - 215 - 2015 17,892 367,487 0 367,487 - 2016 14,066,889 284,315 2 0 284,315 - 2 - 2017 557,641 0 0 0 2018 577,449 508,119 88 0 508,119 - 88 - 2019 64,690 0 58,382 90 58,382 90 2020 93,974 2,958,168 14,368 15 2,943,799 - 2021 743,568 1,466 0 0 1,466 - 0 TOTAL 30,122,404 5,219,749 17 215,447 1 5,004,302 - 17 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-27 Attachment C J. Spanos, Avista Page 387 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 333.00 TURBINES AND GENERATORS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 84-86 121,503 1,657 1 88 0 1,568 - 1 - 85-87 30,288 50 0 235 1 186 1 86-88 128,821 119 0 259 0 141 0 87-89 132,408 69 0 698 1 629 0 88-90 398,815 83,801 21 514 0 83,287 - 21 - 89-91 299,774 120,151 40 2,131 1 118,020 - 39 - 90-92 297,853 120,614 40 8,308 3 112,306 - 38 - 91-93 170,042 69,508 41 10,904 6 58,604 - 34 - 92-94 176,967 34,647 20 9,263 5 25,384 - 14 - 93-95 506,180 39,964 8 6,884 1 33,080 - 7 - 94-96 342,718 7,337 2 4,287 1 3,050 - 1 - 95-97 403,489 5,779 1 5,672 1 107 - 0 96-98 74,473 0 1,385 2 1,385 2 97-99 125,831 0 22,184 18 22,184 18 98-00 76,710 0 20,871 27 20,871 27 99-01 100,840 0 20,938 21 20,938 21 00-02 443,199 0 154 0 154 0 01-03 765,493 49 0 1,142 0 1,093 0 02-04 1,047,605 49 0 1,076 0 1,027 0 03-05 1,009,911 795 - 0 1,061 0 1,855 0 04-06 691,626 1,131 0 0 1,131 - 0 05-07 775,023 157,919 20 0 157,919 - 20 - 06-08 419,136 154,310 37 77 0 154,233 - 37 - 07-09 585,591 152,848 26 1,347 0 151,501 - 26 - 08-10 196,671 5,903 - 3 - 3,875 2 9,778 5 09-11 1,478,326 4,479 - 0 6,163 0 10,642 1 10-12 1,373,174 3,625 - 0 6,843 0 10,468 1 11-13 1,393,888 8,625 1 4,314 0 4,311 - 0 12-14 132,423 55,392 42 1,949 1 53,443 - 40 - 13-15 49,584 176,521 356 0 176,521 - 356 - 14-16 4,715,252 261,006 6 0 261,006 - 6 - 15-17 4,880,807 217,267 4 0 217,267 - 4 - 16-18 5,067,326 264,145 5 0 264,145 - 5 - 17-19 399,927 169,373 42 19,461 5 149,912 - 37 - 18-20 245,371 1,155,429 471 24,250 10 1,131,179 - 461 - 19-21 300,744 986,545 328 24,250 8 962,294 - 320 - FIVE-YEAR AVERAGE 17-21 407,464 693,551 170 14,550 4 679,000 - 167 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-28 Attachment C J. Spanos, Avista Page 388 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 334.00 ACCESSORY ELECTRIC EQUIPMENT SUMMARY OF BOOK SALVAGE 1983 435 0 0 0 1984 50 0 2,700 2,700 1985 8,128 10,502 129 10,004 123 498 - 6 - 1986 5,652 0 0 0 1987 15,467 0 0 0 1988 247 0 0 0 1989 12,109 921 8 25 0 896 - 7 - 1990 136,033 33,123 24 736 1 32,387 - 24 - 1991 41,489 28,745 69 0 28,745 - 69 - 1992 56,048 0 405 1 405 1 1993 10,239 379 4 4,636 45 4,257 42 1994 52,198 6,868 13 29,658 57 22,790 44 1995 38,366 670 2 37,043 97 36,373 95 1996 1,393 0 5,285 379 5,285 379 1997 12,565 0 2,602 21 2,602 21 1998 65,846 706 1 4,746 7 4,040 6 1999 147,856 0 52,525 36 52,525 36 2000 481,776 0 5,798 1 5,798 1 2001 467,432 0 5,705 1 5,705 1 2002 54,392 0 1,242 2 1,242 2 2003 110,200 3,936 4 85,419 78 81,483 74 2004 90,734 0 0 0 2005 78,067 167 0 1,880 2 1,713 2 2006 737,322 12,163 2 0 12,163 - 2 - 2007 210,053 4,085 2 0 4,085 - 2 - 2008 197,416 37,318 19 3,009 2 34,309 - 17 - 2009 99,690 64,900 65 33,363 33 31,537 - 32 - 2010 395,703 0 0 0 2011 14,181 0 0 0 2012 6,648 1,034 16 8,269 124 7,236 109 2013 374,883 7,715 2 0 7,715 - 2 - 2014 395,906 32,804 8 0 32,804 - 8 - 2015 38,095 91,872 241 0 91,872 - 241 - 2016 2,856,982 157,267 6 3,100 0 154,166 - 5 - 2017 638,720 108,726 17 0 108,726 - 17 - 2018 927,344 121,063 13 66 0 120,998 - 13 - 2019 273,111 111,927 41 17,528 6 94,399 - 35 - 2020 915,127 1,785,833 195 33,568 4 1,752,265 - 191 - 2021 580,676 40,386 7 9,654 2 30,732 - 5 - TOTAL 10,548,579 2,663,110 25 358,966 3 2,304,143 - 22 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-29 Attachment C J. Spanos, Avista Page 389 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 334.00 ACCESSORY ELECTRIC EQUIPMENT SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 2,871 3,501 122 4,235 147 734 26 84-86 4,610 3,501 76 4,235 92 734 16 85-87 9,749 3,501 36 3,335 34 166 - 2 - 86-88 7,122 0 0 0 87-89 9,274 307 3 8 0 299 - 3 - 88-90 49,463 11,348 23 254 1 11,094 - 22 - 89-91 63,210 20,930 33 254 0 20,676 - 33 - 90-92 77,857 20,623 26 380 0 20,242 - 26 - 91-93 35,925 9,708 27 1,680 5 8,028 - 22 - 92-94 39,495 2,416 6 11,566 29 9,151 23 93-95 33,601 2,639 8 23,779 71 21,140 63 94-96 30,652 2,513 8 23,995 78 21,483 70 95-97 17,441 223 1 14,977 86 14,753 85 96-98 26,602 235 1 4,211 16 3,976 15 97-99 75,423 235 0 19,958 26 19,722 26 98-00 231,826 235 0 21,023 9 20,788 9 99-01 365,688 0 21,343 6 21,343 6 00-02 334,533 0 4,248 1 4,248 1 01-03 210,675 1,312 1 30,789 15 29,476 14 02-04 85,109 1,312 2 28,887 34 27,575 32 03-05 93,000 1,368 1 29,100 31 27,732 30 04-06 302,041 4,110 1 627 0 3,483 - 1 - 05-07 341,814 5,472 2 627 0 4,845 - 1 - 06-08 381,597 17,855 5 1,003 0 16,852 - 4 - 07-09 169,053 35,434 21 12,124 7 23,310 - 14 - 08-10 230,936 34,073 15 12,124 5 21,949 - 10 - 09-11 169,858 21,633 13 11,121 7 10,512 - 6 - 10-12 138,844 345 0 2,756 2 2,412 2 11-13 131,904 2,916 2 2,756 2 160 - 0 12-14 259,146 13,851 5 2,756 1 11,094 - 4 - 13-15 269,628 44,130 16 0 44,130 - 16 - 14-16 1,096,995 93,981 9 1,033 0 92,947 - 8 - 15-17 1,177,932 119,288 10 1,033 0 118,255 - 10 - 16-18 1,474,349 129,019 9 1,055 0 127,963 - 9 - 17-19 613,058 113,905 19 5,865 1 108,041 - 18 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-30 Attachment C J. Spanos, Avista Page 390 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 334.00 ACCESSORY ELECTRIC EQUIPMENT SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 705,194 672,941 95 17,054 2 655,887 - 93 - 19-21 589,638 646,048 110 20,250 3 625,798 - 106 - FIVE-YEAR AVERAGE 17-21 666,996 433,587 65 12,163 2 421,424 - 63 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-31 Attachment C J. Spanos, Avista Page 391 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.00 MISCELLANEOUS POWER PLANT EQUIPMENT SUMMARY OF BOOK SALVAGE 1983 707 0 0 0 1984 1,143 280 24 5,000 437 4,720 413 1985 5,744 0 0 0 1986 2,580 0 43 2 43 2 1987 24,897 0 0 0 1988 3,109 0 850 27 850 27 1989 195 0 0 0 1990 6,060 1,480 24 0 1,480 - 24 - 1991 71,408 8,095 11 1,061 1 7,034 - 10 - 1992 2,460 4,461 181 1,400 57 3,061 - 124 - 1993 1,161 1,161 1994 40,918 1,437 4 57 0 1,380 - 3 - 1995 35,241 615 2 0 615 - 2 - 1996 1997 1998 18,261 0 548 3 548 3 1999 5,456 0 332 6 332 6 2000 2,509 0 0 0 2001 2002 2003 2004 2005 2006 2007 222,726 0 0 0 2008 2,819 0 0 0 2009 87,863 0 0 0 2010 2011 56,089 0 0 0 2012 2013 91,606 0 0 0 2014 24,773 0 0 0 2015 63,023 0 0 0 2016 421,075 111,920 27 0 111,920 - 27 - 2017 146,674 13,385 9 0 13,385 - 9 - 2018 824 5,792 703 0 5,792 - 703 - 2019 21,676 2,290 11 0 2,290 - 11 - 2020 212,089 675 211,414 - 2021 TOTAL 1,359,833 361,844 27 11,127 1 350,717 - 26 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-32 Attachment C J. Spanos, Avista Page 392 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.00 MISCELLANEOUS POWER PLANT EQUIPMENT SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 2,531 93 4 1,667 66 1,573 62 84-86 3,156 93 3 1,681 53 1,588 50 85-87 11,074 0 14 0 14 0 86-88 10,195 0 298 3 298 3 87-89 9,400 0 283 3 283 3 88-90 3,121 493 16 283 9 210 - 7 - 89-91 25,888 3,192 12 354 1 2,838 - 11 - 90-92 26,643 4,679 18 820 3 3,858 - 14 - 91-93 24,623 4,185 17 1,207 5 2,978 - 12 - 92-94 14,459 1,966 14 873 6 1,093 - 8 - 93-95 25,386 684 3 406 2 278 - 1 - 94-96 25,386 684 3 19 0 665 - 3 - 95-97 11,747 205 2 0 205 - 2 - 96-98 6,087 0 183 3 183 3 97-99 7,906 0 293 4 293 4 98-00 8,742 0 293 3 293 3 99-01 2,655 0 111 4 111 4 00-02 836 0 0 0 01-03 02-04 03-05 04-06 05-07 74,242 0 0 0 06-08 75,182 0 0 0 07-09 104,469 0 0 0 08-10 30,227 0 0 0 09-11 47,984 0 0 0 10-12 18,696 0 0 0 11-13 49,231 0 0 0 12-14 38,793 0 0 0 13-15 59,800 0 0 0 14-16 169,623 37,307 22 0 37,307 - 22 - 15-17 210,257 41,768 20 0 41,768 - 20 - 16-18 189,524 43,699 23 0 43,699 - 23 - 17-19 56,391 7,156 13 0 7,156 - 13 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-33 Attachment C J. Spanos, Avista Page 393 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.00 MISCELLANEOUS POWER PLANT EQUIPMENT SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 7,500 73,390 979 225 3 73,165 - 976 - 19-21 7,225 71,460 989 225 3 71,235 - 986 - FIVE-YEAR AVERAGE 17-21 33,835 46,711 138 135 0 46,576 - 138 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-34 Attachment C J. Spanos, Avista Page 394 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 336.00 ROADS, RAILROADS AND BRIDGES SUMMARY OF BOOK SALVAGE 1994 1,889 249 13 0 249 - 13 - 1995 1996 1997 1998 1999 146 0 0 0 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 30,311 9,530 31 0 9,530 - 31 - 2017 2018 2,372 4,238 179 0 4,238 - 179 - 2019 2,914 2,914 - 2020 2021 TOTAL 34,718 16,932 49 0 16,932 - 49 - THREE-YEAR MOVING AVERAGES 94-96 630 83 13 0 83 - 13 - 95-97 96-98 97-99 49 0 0 0 98-00 49 0 0 0 99-01 49 0 0 0 00-02 01-03 02-04 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-35 Attachment C J. Spanos, Avista Page 395 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 336.00 ROADS, RAILROADS AND BRIDGES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 03-05 04-06 05-07 06-08 07-09 08-10 09-11 10-12 11-13 12-14 13-15 14-16 10,104 3,177 31 0 3,177 - 31 - 15-17 10,104 3,177 31 0 3,177 - 31 - 16-18 10,894 4,590 42 0 4,590 - 42 - 17-19 790 2,384 302 0 2,384 - 302 - 18-20 790 2,384 302 0 2,384 - 302 - 19-21 971 971 - FIVE-YEAR AVERAGE 17-21 474 1,430 302 0 1,430 - 302 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-36 Attachment C J. Spanos, Avista Page 396 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 341.00 STRUCTURES AND IMPROVEMENTS SUMMARY OF BOOK SALVAGE 2010 6,880 915 13 0 915- 13 - 2011 4,500 - 4,500 2012 2013 23,474 0 0 0 2014 2015 2016 4,010 0 0 0 2017 5,175 0 0 0 2018 9,313 0 0 0 2019 2020 17,878 0 0 0 2021 95,195 0 0 0 TOTAL 161,924 3,585 - 2 - 0 3,585 2 THREE-YEAR MOVING AVERAGES 10-12 2,293 1,195 - 52 - 0 1,195 52 11-13 7,824 1,500 - 19 - 0 1,500 19 12-14 7,824 0 0 0 13-15 7,824 0 0 0 14-16 1,337 0 0 0 15-17 3,062 0 0 0 16-18 6,166 0 0 0 17-19 4,829 0 0 0 18-20 9,064 0 0 0 19-21 37,691 0 0 0 FIVE-YEAR AVERAGE 17-21 25,512 0 0 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-37 Attachment C J. Spanos, Avista Page 397 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 342.00 FUEL HOLDERS, PRODUCERS AND ACCESSORIES SUMMARY OF BOOK SALVAGE 1999 22,342 7,461 33 0 7,461- 33 - 2000 2001 2002 2003 2004 2005 382,706 0 0 0 2006 362 0 0 0 2007 2008 2009 732,116 732,116- 2010 17,815 490 3 0 490- 3 - 2011 2012 2013 2014 2015 269,222 0 0 0 2016 2017 15,771 0 0 0 2018 89,854 0 0 0 2019 970 970- 2020 2,516 0 0 0 2021 33,742 - 33,742 TOTAL 800,588 707,294 88 0 707,294- 88 - THREE-YEAR MOVING AVERAGES 99-01 7,447 2,487 33 0 2,487- 33 - 00-02 01-03 02-04 03-05 127,569 0 0 0 04-06 127,689 0 0 0 05-07 127,689 0 0 0 06-08 121 0 0 0 07-09 244,039 244,039- 08-10 5,938 244,202 0 244,202- 09-11 5,938 244,202 0 244,202- 10-12 5,938 163 3 0 163- 3 - 11-13 12-14 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-38 Attachment C J. Spanos, Avista Page 398 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 342.00 FUEL HOLDERS, PRODUCERS AND ACCESSORIES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 13-15 89,740 0 0 0 14-16 89,740 0 0 0 15-17 94,998 0 0 0 16-18 35,208 0 0 0 17-19 35,208 323 1 0 323- 1 - 18-20 30,790 323 1 0 323- 1 - 19-21 839 10,924 - 0 10,924 FIVE-YEAR AVERAGE 17-21 21,628 6,554 - 30 - 0 6,554 30 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-39 Attachment C J. Spanos, Avista Page 399 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 343.00 PRIME MOVERS SUMMARY OF BOOK SALVAGE 2002 200,000 0 0 0 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 31,468 0 0 0 2013 2014 2015 2016 2017 2018 401,409 0 0 0 2019 2020 2021 TOTAL 632,878 0 0 0 THREE-YEAR MOVING AVERAGES 02-04 66,667 0 0 0 03-05 04-06 05-07 06-08 07-09 08-10 09-11 10-12 10,490 0 0 0 11-13 10,490 0 0 0 12-14 10,490 0 0 0 13-15 14-16 15-17 16-18 133,803 0 0 0 17-19 133,803 0 0 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-40 Attachment C J. Spanos, Avista Page 400 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 343.00 PRIME MOVERS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 133,803 0 0 0 19-21 FIVE-YEAR AVERAGE 17-21 80,282 0 0 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-41 Attachment C J. Spanos, Avista Page 401 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 344.00 GENERATORS SUMMARY OF BOOK SALVAGE 1999 14,036 0 0 0 2000 2001 2002 20,981 2,245 18,736- 2003 22 22- 2004 2005 3,702,752 0 0 0 2006 819,944 0 0 0 2007 5,784 0 0 0 2008 9,162,288 1,268 0 3,886 0 2,618 0 2009 2010 237,690 0 0 0 2011 2012 2,248,555 0 0 0 2013 5,985 0 0 0 2014 2015 1,390 0 0 0 2016 14,653,336 11,055 0 0 11,055- 0 2017 34,592 0 0 0 2018 280,407 0 0 0 2019 144,769 58,143 40 0 58,143- 40 - 2020 62,086 6,065 10 0 6,065- 10 - 2021 403,436 3,665 1 0 3,665- 1 - TOTAL 31,777,050 101,199 0 6,131 0 95,068- 0 THREE-YEAR MOVING AVERAGES 99-01 4,679 0 0 0 00-02 6,994 748 6,245- 01-03 7,001 748 6,253- 02-04 7,001 748 6,253- 03-05 1,234,251 7 0 0 7- 0 04-06 1,507,565 0 0 0 05-07 1,509,493 0 0 0 06-08 3,329,339 423 0 1,295 0 873 0 07-09 3,056,024 423 0 1,295 0 873 0 08-10 3,133,326 423 0 1,295 0 873 0 09-11 79,230 0 0 0 10-12 828,748 0 0 0 11-13 751,513 0 0 0 12-14 751,513 0 0 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-42 Attachment C J. Spanos, Avista Page 402 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 344.00 GENERATORS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 13-15 2,458 0 0 0 14-16 4,884,909 3,685 0 0 3,685- 0 15-17 4,896,439 3,685 0 0 3,685- 0 16-18 4,989,445 3,685 0 0 3,685- 0 17-19 153,256 19,381 13 0 19,381- 13 - 18-20 162,421 21,403 13 0 21,403- 13 - 19-21 203,431 22,624 11 0 22,624- 11 - FIVE-YEAR AVERAGE 17-21 185,058 13,575 7 0 13,575- 7 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-43 Attachment C J. Spanos, Avista Page 403 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 345.00 ACCESSORY ELECTRIC EQUIPMENT SUMMARY OF BOOK SALVAGE 1995 220 220 1996 3,825 3,825 - 1997 1998 1999 2000 2001 85 85 2002 2003 2004 2005 2,569 0 0 0 2006 11,528 0 0 0 2007 10,736 116 - 1 - 0 116 1 2008 457,745 20,438 4 0 20,438 - 4 - 2009 57,927 0 7,794 13 7,794 13 2010 319,179 20,000 6 1,004 0 18,996 - 6 - 2011 407,148 0 0 0 2012 21,829 179 - 1 - 0 179 1 2013 1,313,870 0 0 0 2014 135,390 0 0 0 2015 92,683 179 0 0 179 - 0 2016 191,277 434 0 2,641 1 2,207 1 2017 47,595 0 0 0 2018 15,912 0 0 0 2019 86,990 20,872 24 904 1 19,968 - 23 - 2020 5,153 0 365 7 365 7 2021 30,669 81,956 267 0 81,956 - 267 - TOTAL 3,208,199 147,409 5 13,014 0 134,395 - 4 - THREE-YEAR MOVING AVERAGES 95-97 1,275 73 1,202- 96-98 1,275 1,275- 97-99 98-00 99-01 28 28 00-02 28 28 01-03 28 28 02-04 03-05 856 0 0 0 04-06 4,699 0 0 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-44 Attachment C J. Spanos, Avista Page 404 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 345.00 ACCESSORY ELECTRIC EQUIPMENT SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 05-07 8,278 39 - 0 0 39 0 06-08 160,003 6,774 4 0 6,774- 4 - 07-09 175,469 6,774 4 2,598 1 4,176- 2 - 08-10 278,284 13,479 5 2,933 1 10,547- 4 - 09-11 261,418 6,667 3 2,933 1 3,734- 1 - 10-12 249,385 6,607 3 335 0 6,272- 3 - 11-13 580,949 60 - 0 0 60 0 12-14 490,363 60 - 0 0 60 0 13-15 513,981 60 0 0 60- 0 14-16 139,783 204 0 880 1 676 0 15-17 110,518 204 0 880 1 676 1 16-18 84,928 145 0 880 1 736 1 17-19 50,166 6,957 14 301 1 6,656- 13 - 18-20 36,018 6,957 19 423 1 6,534- 18 - 19-21 40,937 34,276 84 423 1 33,853- 83 - FIVE-YEAR AVERAGE 17-21 37,264 20,566 55 254 1 20,312- 55 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-45 Attachment C J. Spanos, Avista Page 405 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 346.00 MISCELLANEOUS POWER PLANT EQUIPMENT SUMMARY OF BOOK SALVAGE 2008 23,037 0 0 0 2009 2010 9,099 0 0 0 2011 409 409- 2012 44,370 0 0 0 2013 356,713 0 0 0 2014 1,262 0 0 0 2015 33,674 0 0 0 2016 4,736 4,736- 2017 1,585 0 0 0 2018 2019 2020 2021 TOTAL 469,739 5,145 1 0 5,145- 1 - THREE-YEAR MOVING AVERAGES 08-10 10,712 0 0 0 09-11 3,033 136 4 0 136 - 4 - 10-12 17,823 136 1 0 136 - 1 - 11-13 133,694 136 0 0 136 - 0 12-14 134,115 0 0 0 13-15 130,549 0 0 0 14-16 11,645 1,579 14 0 1,579 - 14 - 15-17 11,753 1,579 13 0 1,579 - 13 - 16-18 528 1,579 299 0 1,579 - 299 - 17-19 528 0 0 0 18-20 19-21 FIVE-YEAR AVERAGE 17-21 317 0 0 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-46 Attachment C J. Spanos, Avista Page 406 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 352.00 STRUCTURES AND IMPROVEMENTS SUMMARY OF BOOK SALVAGE 1983 6,020 0 0 0 1984 1985 460 0 0 0 1986 6,769 4,481 66 25 0 4,456 - 66 - 1987 1988 10,568 1,969 19 0 1,969 - 19 - 1989 1,700 594 35 0 594 - 35 - 1990 1991 1,960 473 24 0 473 - 24 - 1992 1993 1994 1,460 627 43 1,810 124 1,183 81 1995 14,029 6,877 49 1,209 9 5,668 - 40 - 1996 1997 227 227 1998 2,391 548 23 104 4 444 - 19 - 1999 3,537 128 3,409 - 2000 16,945 1,247 7 176 1 1,072 - 6 - 2001 44,098 399 1 347 1 51 - 0 2002 19,273 231 1 318 2 87 0 2003 634 833 199 2004 4,917 0 0 0 2005 25,271 1,597 - 6 - 2,244 9 3,840 15 2006 83 - 3,250 3,333 2007 7,317 4,502 62 63 1 4,439 - 61 - 2008 424 5,632 18,451 12,819 2009 2010 207,863 6,222 3 2,735 1 3,487 - 2 - 2011 10,736 2,044 8,692 - 2012 61,592 1,260 2 0 1,260 - 2 - 2013 18,295 6,287 34 0 6,287 - 34 - 2014 118,869 15,343 13 0 15,343 - 13 - 2015 28,345 24,829 88 0 24,829 - 88 - 2016 156,096 19,461 12 0 19,461 - 12 - 2017 68,762 511 1 0 511 - 1 - 2018 22,140 77,685 351 11,547 52 66,138 - 299 - 2019 17,218 5,678 33 0 5,678 - 33 - 2020 49,043 4,792 10 3,593 7 1,199 - 2 - 2021 1,227 0 0 0 TOTAL 913,051 202,875 22 49,104 5 153,771 - 17 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-47 Attachment C J. Spanos, Avista Page 407 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 352.00 STRUCTURES AND IMPROVEMENTS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 2,160 0 0 0 84-86 2,410 1,494 62 8 0 1,485 - 62 - 85-87 2,410 1,494 62 8 0 1,485 - 62 - 86-88 5,779 2,150 37 8 0 2,142 - 37 - 87-89 4,089 854 21 0 854 - 21 - 88-90 4,089 854 21 0 854 - 21 - 89-91 1,220 356 29 0 356 - 29 - 90-92 653 158 24 0 158 - 24 - 91-93 653 158 24 0 158 - 24 - 92-94 487 209 43 603 124 394 81 93-95 5,163 2,501 48 1,006 19 1,495 - 29 - 94-96 5,163 2,501 48 1,006 19 1,495 - 29 - 95-97 4,676 2,292 49 479 10 1,814 - 39 - 96-98 797 183 23 110 14 72 - 9 - 97-99 797 1,362 171 153 19 1,209 - 152 - 98-00 6,445 1,777 28 136 2 1,641 - 25 - 99-01 20,348 1,728 8 217 1 1,510 - 7 - 00-02 26,772 626 2 280 1 345 - 1 - 01-03 21,124 421 2 500 2 78 0 02-04 8,063 288 4 384 5 95 1 03-05 10,062 321 - 3 - 1,026 10 1,347 13 04-06 10,062 560 - 6 - 1,831 18 2,391 24 05-07 10,863 941 9 1,852 17 911 8 06-08 2,580 3,350 130 7,255 281 3,904 151 07-09 2,580 3,378 131 6,171 239 2,793 108 08-10 69,429 3,951 6 7,062 10 3,111 4 09-11 69,288 5,653 8 1,593 2 4,060 - 6 - 10-12 89,818 6,073 7 1,593 2 4,480 - 5 - 11-13 26,629 6,094 23 681 3 5,413 - 20 - 12-14 66,252 7,630 12 0 7,630 - 12 - 13-15 55,170 15,487 28 0 15,487 - 28 - 14-16 101,103 19,878 20 0 19,878 - 20 - 15-17 84,401 14,934 18 0 14,934 - 18 - 16-18 82,332 32,552 40 3,849 5 28,703 - 35 - 17-19 36,040 27,958 78 3,849 11 24,109 - 67 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-48 Attachment C J. Spanos, Avista Page 408 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 352.00 STRUCTURES AND IMPROVEMENTS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 29,467 29,385 100 5,047 17 24,338 - 83 - 19-21 22,496 3,490 16 1,198 5 2,292 - 10 - FIVE-YEAR AVERAGE 17-21 31,678 17,733 56 3,028 10 14,705 - 46 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-49 Attachment C J. Spanos, Avista Page 409 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 353.00 STATION EQUIPMENT SUMMARY OF BOOK SALVAGE 1983 445,432 227,088 51 66,374 15 160,714 - 36 - 1984 165,959 94,324 57 25,784 16 68,540 - 41 - 1985 1,077,842 339,232 31 112,521 10 226,711 - 21 - 1986 162,746 110,905 68 55,587 34 55,318 - 34 - 1987 203,713 123,245 60 11,937 6 111,308 - 55 - 1988 728,191 135,725 19 16,152 2 119,573 - 16 - 1989 310,641 108,486 35 34,112 11 74,374 - 24 - 1990 4,771 4,771 1991 454,502 109,551 24 76,007 17 33,544 - 7 - 1992 36,168 59,200 164 1,479 4 57,721 - 160 - 1993 60,781 122,543 202 10,606 17 111,937 - 184 - 1994 164,125 70,488 43 25,033 15 45,455 - 28 - 1995 435,836 213,653 49 225,212 52 11,559 3 1996 286,267 92,596 32 30,977 11 61,619 - 22 - 1997 195,666 102,758 53 26,288 13 76,470 - 39 - 1998 711,241 163,110 23 13,497 2 149,613 - 21 - 1999 330,868 47,322 14 14,811 4 32,511 - 10 - 2000 1,405,203 145,503 10 20,485 1 125,018 - 9 - 2001 1,023,964 46,504 5 40,538 4 5,965 - 1 - 2002 337,391 26,984 8 37,098 11 10,113 3 2003 908,688 73,970 8 97,243 11 23,273 3 2004 672,150 60,759 9 46,286 7 14,473 - 2 - 2005 1,087,486 11,947 1 14,690 1 2,743 0 2006 708,433 5,547 - 1 - 105,834 15 111,381 16 2007 2,454,474 26,154 1 78,987 3 52,832 2 2008 872,747 16,286 2 192,998 22 176,712 20 2009 1,938,336 316,046 16 39,056 2 276,990 - 14 - 2010 2,683,011 17,320 1 97,441 4 80,120 3 2011 1,882,931 100,077 5 98,105 5 1,972 - 0 2012 714,053 67,805 9 2,930 0 64,875 - 9 - 2013 1,266,861 136,223 11 0 136,223 - 11 - 2014 5,045,898 332,576 7 0 332,576 - 7 - 2015 984,823 398,496 40 99,686 10 298,810 - 30 - 2016 4,790,551 428,428 9 5 0 428,423 - 9 - 2017 4,334,329 261,043 6 108,514 3 152,529 - 4 - 2018 2,547,005 295,061 12 110,133 4 184,928 - 7 - 2019 638,457 517,834 81 46,653 7 471,181 - 74 - 2020 228,954 600,377 262 103,887 45 496,490 - 217 - 2021 5,620,842 352,655 6 33,020 1 319,634 - 6 - TOTAL 47,916,566 6,346,727 13 2,124,736 4 4,221,991 - 9 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-50 Attachment C J. Spanos, Avista Page 410 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 353.00 STATION EQUIPMENT SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 563,078 220,215 39 68,226 12 151,988- 27 - 84-86 468,849 181,487 39 64,631 14 116,856- 25 - 85-87 481,434 191,127 40 60,015 12 131,112- 27 - 86-88 364,883 123,292 34 27,892 8 95,400- 26 - 87-89 414,182 122,485 30 20,734 5 101,752- 25 - 88-90 346,277 81,404 24 18,345 5 63,059- 18 - 89-91 255,048 72,679 28 38,297 15 34,382- 13 - 90-92 163,557 56,250 34 27,419 17 28,831- 18 - 91-93 183,817 97,098 53 29,364 16 67,734- 37 - 92-94 87,025 84,077 97 12,373 14 71,704- 82 - 93-95 220,247 135,561 62 86,950 39 48,611- 22 - 94-96 295,409 125,579 43 93,741 32 31,838- 11 - 95-97 305,923 136,336 45 94,159 31 42,177- 14 - 96-98 397,725 119,488 30 23,587 6 95,901- 24 - 97-99 412,592 104,397 25 18,199 4 86,198- 21 - 98-00 815,770 118,645 15 16,264 2 102,381- 13 - 99-01 920,012 79,776 9 25,278 3 54,498- 6 - 00-02 922,186 72,997 8 32,707 4 40,290- 4 - 01-03 756,681 49,153 6 58,293 8 9,140 1 02-04 639,410 53,904 8 60,209 9 6,304 1 03-05 889,441 48,892 5 52,739 6 3,848 0 04-06 822,690 22,386 3 55,603 7 33,217 4 05-07 1,416,798 10,851 1 66,504 5 55,652 4 06-08 1,345,218 12,298 1 125,940 9 113,642 8 07-09 1,755,186 119,495 7 103,680 6 15,815- 1 - 08-10 1,831,365 116,551 6 109,832 6 6,719- 0 09-11 2,168,093 144,481 7 78,201 4 66,280- 3 - 10-12 1,759,998 61,734 4 66,159 4 4,424 0 11-13 1,287,948 101,369 8 33,678 3 67,690- 5 - 12-14 2,342,271 178,868 8 977 0 177,891- 8 - 13-15 2,432,527 289,098 12 33,229 1 255,870- 11 - 14-16 3,607,091 386,500 11 33,230 1 353,270- 10 - 15-17 3,369,901 362,656 11 69,402 2 293,254- 9 - 16-18 3,890,628 328,177 8 72,884 2 255,293- 7 - 17-19 2,506,597 357,979 14 88,433 4 269,546- 11 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-51 Attachment C J. Spanos, Avista Page 411 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 353.00 STATION EQUIPMENT SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 1,138,139 471,090 41 86,891 8 384,200- 34 - 19-21 2,162,751 490,288 23 61,187 3 429,102- 20 - FIVE-YEAR AVERAGE 17-21 2,673,918 405,394 15 80,441 3 324,952- 12 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-52 Attachment C J. Spanos, Avista Page 412 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 354.00 TOWERS AND FIXTURES SUMMARY OF BOOK SALVAGE 1985 293 293 1986 1987 1988 1989 4,330 4,330 1990 15,149 15,518 102 0 15,518 - 102 - 1991 234 56 24 0 56 - 24 - 1992 1993 1994 1995 1996 1997 1998 1999 2000 50,309 0 0 0 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 953 20 933 - 2016 2017 2018 7,300 0 0 0 2019 2020 2021 127,584 127,584 - TOTAL 72,991 144,111 197 4,643 6 139,468 - 191 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-53 Attachment C J. Spanos, Avista Page 413 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 354.00 TOWERS AND FIXTURES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 85-87 98 98 86-88 87-89 1,443 1,443 88-90 5,050 5,173 102 1,443 29 3,729 - 74 - 89-91 5,128 5,191 101 1,443 28 3,748 - 73 - 90-92 5,128 5,191 101 0 5,191 - 101 - 91-93 78 19 24 0 19 - 24 - 92-94 93-95 94-96 95-97 96-98 97-99 98-00 16,770 0 0 0 99-01 16,770 0 0 0 00-02 16,770 0 0 0 01-03 02-04 03-05 04-06 05-07 06-08 07-09 08-10 09-11 10-12 11-13 12-14 13-15 318 7 311 - 14-16 318 7 311 - 15-17 318 7 311 - 16-18 2,433 0 0 0 17-19 2,433 0 0 0 18-20 2,433 0 0 0 19-21 42,528 42,528 - FIVE-YEAR AVERAGE 17-21 1,460 25,517 0 25,517 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-54 Attachment C J. Spanos, Avista Page 414 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 355.00 POLES AND FIXTURES SUMMARY OF BOOK SALVAGE 1983 274,311 139,848 51 18,559 7 121,289 - 44 - 1984 374,785 213,024 57 21,525 6 191,499 - 51 - 1985 1,245,813 392,143 31 295,376 24 96,767 - 8 - 1986 811,208 554,526 68 131,904 16 422,622 - 52 - 1987 90,892 54,909 60 80,445 89 25,536 28 1988 65,003 12,119 19 17,686 27 5,567 9 1989 94,789 33,104 35 12,249 13 20,855 - 22 - 1990 138,936 142,314 102 54,335 39 87,979 - 63 - 1991 180,873 43,597 24 42,353 23 1,244 - 1 - 1992 79,852 130,513 163 35,012 44 95,501 - 120 - 1993 87,483 176,379 202 65,002 74 111,377 - 127 - 1994 212,716 91,356 43 42,018 20 49,338 - 23 - 1995 32,629 15,995 49 65,337 200 49,342 151 1996 72,155 23,339 32 7,808 11 15,531 - 22 - 1997 156,946 82,423 53 12,688 8 69,735 - 44 - 1998 77,362 17,741 23 69,608 90 51,867 67 1999 237,250 13,539 6 9,098 4 4,442 - 2 - 2000 243,836 88,475 36 12,456 5 76,019 - 31 - 2001 87,098 28,277 32 24,650 28 3,627 - 4 - 2002 85,477 16,408 19 22,558 26 6,150 7 2003 96,277 44,978 47 59,130 61 14,151 15 2004 485,314 42,976 9 32,739 7 10,237 - 2 - 2005 101,147 99,604 98 41,325 41 58,279 - 58 - 2006 489,775 24,627 - 5 - 22,758 5 47,384 10 2007 143,462 86,928 61 29,320 20 57,608 - 40 - 2008 558,008 52,260 9 59,725 11 7,466 1 2009 98,793 142,712 144 2,080 2 140,631 - 142 - 2010 127,134 162,730 128 13,404 11 149,326 - 117 - 2011 106,856 217,625 204 79,618 75 138,007 - 129 - 2012 364,024 22,940 6 456 0 22,484 - 6 - 2013 816,192 46,106 6 0 46,106 - 6 - 2014 648,732 254,992 39 3,898 1 251,094 - 39 - 2015 427,536 471,061 110 1,258 0 469,803 - 110 - 2016 508,362 152,193 30 0 152,193 - 30 - 2017 1,489,941 1,562,755 105 10,582 1 1,552,173 - 104 - 2018 1,955,104 945,159 48 39,124 2 906,035 - 46 - 2019 887,580 1,011,541 114 13,021 1 998,520 - 112 - 2020 751,245 626,213 83 14,210 2 612,004 - 81 - 2021 1,734,967 27,162 2 2,500 0 24,662 - 1 - TOTAL 16,439,865 8,215,339 50 1,465,813 9 6,749,526 - 41 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-55 Attachment C J. Spanos, Avista Page 415 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 355.00 POLES AND FIXTURES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 631,636 248,338 39 111,820 18 136,518 - 22 - 84-86 810,602 386,564 48 149,602 18 236,963 - 29 - 85-87 715,971 333,859 47 169,242 24 164,618 - 23 - 86-88 322,368 207,185 64 76,678 24 130,506 - 40 - 87-89 83,561 33,377 40 36,793 44 3,416 4 88-90 99,576 62,512 63 28,090 28 34,422 - 35 - 89-91 138,199 73,005 53 36,312 26 36,693 - 27 - 90-92 133,220 105,475 79 43,900 33 61,575 - 46 - 91-93 116,069 116,830 101 47,456 41 69,374 - 60 - 92-94 126,684 132,749 105 47,344 37 85,405 - 67 - 93-95 110,943 94,577 85 57,452 52 37,124 - 33 - 94-96 105,833 43,563 41 38,388 36 5,176 - 5 - 95-97 87,243 40,586 47 28,611 33 11,975 - 14 - 96-98 102,154 41,168 40 30,035 29 11,133 - 11 - 97-99 157,186 37,901 24 30,465 19 7,437 - 5 - 98-00 186,149 39,918 21 30,387 16 9,531 - 5 - 99-01 189,395 43,430 23 15,401 8 28,029 - 15 - 00-02 138,804 44,387 32 19,888 14 24,499 - 18 - 01-03 89,617 29,888 33 35,446 40 5,558 6 02-04 222,356 34,787 16 38,142 17 3,355 2 03-05 227,579 62,519 27 44,398 20 18,122 - 8 - 04-06 358,745 39,318 11 32,274 9 7,044 - 2 - 05-07 244,795 53,968 22 31,134 13 22,834 - 9 - 06-08 397,082 38,187 10 37,268 9 919 - 0 07-09 266,755 93,966 35 30,375 11 63,591 - 24 - 08-10 261,312 119,234 46 25,070 10 94,164 - 36 - 09-11 110,928 174,356 157 31,701 29 142,655 - 129 - 10-12 199,338 134,432 67 31,159 16 103,273 - 52 - 11-13 429,024 95,557 22 26,691 6 68,866 - 16 - 12-14 609,649 108,013 18 1,451 0 106,562 - 17 - 13-15 630,820 257,387 41 1,719 0 255,668 - 41 - 14-16 528,210 292,749 55 1,719 0 291,030 - 55 - 15-17 808,613 728,670 90 3,947 0 724,723 - 90 - 16-18 1,317,803 886,702 67 16,569 1 870,134 - 66 - 17-19 1,444,208 1,173,152 81 20,909 1 1,152,243 - 80 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-56 Attachment C J. Spanos, Avista Page 416 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 355.00 POLES AND FIXTURES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 1,197,976 860,971 72 22,118 2 838,853 - 70 - 19-21 1,124,597 554,972 49 9,910 1 545,062 - 48 - FIVE-YEAR AVERAGE 17-21 1,363,767 834,566 61 15,887 1 818,679 - 60 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-57 Attachment C J. Spanos, Avista Page 417 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 356.00 OVERHEAD CONDUCTORS AND DEVICES SUMMARY OF BOOK SALVAGE 1983 257,115 131,080 51 299,551 117 168,471 66 1984 158,917 90,307 57 212,053 133 121,746 77 1985 1,355,015 426,414 31 391,143 29 35,271 - 3 - 1986 658,627 450,343 68 266,239 40 184,104 - 28 - 1987 36,550 22,244 61 42,730 117 20,486 56 1988 48,446 9,023 19 23,952 49 14,929 31 1989 63,639 22,225 35 42,008 66 19,783 31 1990 85,920 88,009 102 162,421 189 74,412 87 1991 116,736 28,137 24 33,405 29 5,268 5 1992 50,512 82,559 163 66,702 132 15,857 - 31 - 1993 196,212 395,593 202 145,276 74 250,317 - 128 - 1994 187,953 80,721 43 49,494 26 31,227 - 17 - 1995 27,037 13,254 49 66,764 247 53,510 198 1996 40,822 13,204 32 4,417 11 8,787 - 22 - 1997 175,891 92,372 53 283,887 161 191,515 109 1998 57,287 13,138 23 27,180 47 14,042 25 1999 266,779 6,374 2 10,470 4 4,096 2 2000 102,127 101,822 100 14,335 14 87,487 - 86 - 2001 109,461 32,543 30 28,368 26 4,174 - 4 - 2002 110,997 18,883 17 25,961 23 7,077 6 2003 115,840 51,764 45 68,050 59 16,286 14 2004 493,775 44,458 9 33,867 7 10,590 - 2 - 2005 85,049 110,597 130 131,560 155 20,963 25 2006 646,345 224,589 - 35 - 24,354 4 248,943 39 2007 103,911 17,021 16 15,201 15 1,820 - 2 - 2008 545,662 44,358 8 27,297 5 17,061 - 3 - 2009 17,544 108,793 620 1,994 11 106,799 - 609 - 2010 75,173 46,140 61 3,729 5 42,412 - 56 - 2011 23,291 72,734 312 45,554 196 27,180 - 117 - 2012 48,436 11,080 23 218 0 10,862 - 22 - 2013 637,694 20,957 3 0 20,957 - 3 - 2014 101,850 193,620 190 3,898 4 189,722 - 186 - 2015 214,627 172,074 80 2,091 1 169,983 - 79 - 2016 143,535 64,869 45 0 64,869 - 45 - 2017 718,665 278,824 39 1,351 0 277,473 - 39 - 2018 1,341,419 354,769 26 8,177 1 346,592 - 26 - 2019 315,401 310,789 99 4,078 1 306,711 - 97 - 2020 276,819 651,730 235 10,026 4 641,703 - 232 - 2021 1,874,728 121,507 6 2,688 0 118,819 - 6 - TOTAL 11,885,806 4,569,740 38 2,580,487 22 1,989,253 - 17 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-58 Attachment C J. Spanos, Avista Page 418 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 356.00 OVERHEAD CONDUCTORS AND DEVICES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 590,349 215,934 37 300,916 51 84,982 14 84-86 724,186 322,355 45 289,812 40 32,543 - 4 - 85-87 683,397 299,667 44 233,371 34 66,296 - 10 - 86-88 247,874 160,537 65 110,974 45 49,563 - 20 - 87-89 49,545 17,831 36 36,230 73 18,399 37 88-90 66,002 39,752 60 76,127 115 36,375 55 89-91 88,765 46,124 52 79,278 89 33,154 37 90-92 84,389 66,235 78 87,509 104 21,274 25 91-93 121,153 168,763 139 81,794 68 86,969 - 72 - 92-94 144,892 186,291 129 87,157 60 99,134 - 68 - 93-95 137,067 163,189 119 87,178 64 76,011 - 55 - 94-96 85,271 35,726 42 40,225 47 4,499 5 95-97 81,250 39,610 49 118,356 146 78,746 97 96-98 91,333 39,571 43 105,161 115 65,590 72 97-99 166,652 37,295 22 107,179 64 69,884 42 98-00 142,064 40,445 28 17,328 12 23,116 - 16 - 99-01 159,456 46,913 29 17,724 11 29,188 - 18 - 00-02 107,528 51,083 48 22,888 21 28,195 - 26 - 01-03 112,099 34,397 31 40,793 36 6,396 6 02-04 240,204 38,368 16 42,626 18 4,258 2 03-05 231,555 68,940 30 77,826 34 8,886 4 04-06 408,390 23,178- 6 - 63,260 15 86,438 21 05-07 278,435 32,324- 12 - 57,038 20 89,362 32 06-08 431,973 54,403- 13 - 22,284 5 76,687 18 07-09 222,372 56,724 26 14,831 7 41,893 - 19 - 08-10 212,793 66,430 31 11,007 5 55,424 - 26 - 09-11 38,669 75,889 196 17,092 44 58,797 - 152 - 10-12 48,967 43,318 88 16,500 34 26,818 - 55 - 11-13 236,474 34,924 15 15,257 6 19,666 - 8 - 12-14 262,660 75,219 29 1,372 1 73,847 - 28 - 13-15 318,057 128,884 41 1,996 1 126,887 - 40 - 14-16 153,337 143,521 94 1,996 1 141,525 - 92 - 15-17 358,942 171,922 48 1,147 0 170,775 - 48 - 16-18 734,540 232,821 32 3,176 0 229,645 - 31 - 17-19 791,828 314,794 40 4,535 1 310,259 - 39 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-59 Attachment C J. Spanos, Avista Page 419 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 356.00 OVERHEAD CONDUCTORS AND DEVICES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 644,547 439,096 68 7,427 1 431,669 - 67 - 19-21 822,316 361,342 44 5,597 1 355,745 - 43 - FIVE-YEAR AVERAGE 17-21 905,407 343,524 38 5,264 1 338,260 - 37 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-60 Attachment C J. Spanos, Avista Page 420 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 358.00 UNDERGROUND CONDUCTORS AND DEVICES SUMMARY OF BOOK SALVAGE 1985 18,669 0 0 0 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 108,000 9,214 9 24,786 23 15,572 14 2009 2010 2011 2012 2013 2014 2015 289 279 10- 2016 2017 2018 2019 2020 2021 366,405 0 0 0 TOTAL 493,074 9,502 2 25,065 5 15,562 3 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-61 Attachment C J. Spanos, Avista Page 421 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 358.00 UNDERGROUND CONDUCTORS AND DEVICES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 85-87 6,223 0 0 0 86-88 87-89 88-90 89-91 90-92 91-93 92-94 93-95 94-96 95-97 96-98 97-99 98-00 99-01 00-02 01-03 02-04 03-05 04-06 05-07 06-08 36,000 3,071 9 8,262 23 5,191 14 07-09 36,000 3,071 9 8,262 23 5,191 14 08-10 36,000 3,071 9 8,262 23 5,191 14 09-11 10-12 11-13 12-14 13-15 96 93 3- 14-16 96 93 3- 15-17 96 93 3- 16-18 17-19 18-20 19-21 122,135 0 0 0 FIVE-YEAR AVERAGE 17-21 73,281 0 0 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-62 Attachment C J. Spanos, Avista Page 422 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 361.00 STRUCTURES AND IMPROVEMENTS SUMMARY OF BOOK SALVAGE 1983 39,133 8,574 22 0 8,574 - 22 - 1984 17,296 5,327 31 0 5,327 - 31 - 1985 1,103 463 42 0 463 - 42 - 1986 6,068 3,604 59 0 3,604 - 59 - 1987 114,221 26,297 23 31,826 - 28 - 58,123 - 51 - 1988 42,061 11,462 27 0 11,462 - 27 - 1989 9,160 1,718 19 4,907 54 3,189 35 1990 26,287 8,712 33 0 8,712 - 33 - 1991 6,804 2,722 40 0 2,722 - 40 - 1992 1993 5,272 1,294 25 0 1,294 - 25 - 1994 17,264 3,287 19 0 3,287 - 19 - 1995 1,933 0 7,042 364 7,042 364 1996 1997 9,118 2,246 25 0 2,246 - 25 - 1998 77,578 13,366 17 0 13,366 - 17 - 1999 25,104 43,085 172 0 43,085 - 172 - 2000 54,984 0 0 0 2001 11,465 0 0 0 2002 19,845 0 0 0 2003 14,275 0 0 0 2004 2005 22,474 0 0 0 2006 207,980 1,219- 1 - 407 0 1,626 1 2007 21,253 0 6 0 6 0 2008 33,925 10,776 32 329 1 10,447 - 31 - 2009 22,861 11,052 11,809 - 2010 4,197 7,255 173 2,643 63 4,612 - 110 - 2011 39,973 24,747 15,226 - 2012 119,427 2,560 2 153,571 129 151,011 126 2013 82,392 1,843 2 0 1,843 - 2 - 2014 47,698 5,504- 12 - 0 5,504 12 2015 51,819 84,918 164 18,688 36 66,230 - 128 - 2016 255,145 76,186 30 0 76,186 - 30 - 2017 154,628 41,891 27 511 0 41,379 - 27 - 2018 83,430 99,067 119 0 99,067 - 119 - 2019 112,985 15,991 14 0 15,991 - 14 - 2020 4,429 26,380 596 7,436 168 18,944 - 428 - 2021 18,098 0 0 0 TOTAL 1,718,850 555,135 32 199,513 12 355,623 - 21 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-63 Attachment C J. Spanos, Avista Page 423 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 361.00 STRUCTURES AND IMPROVEMENTS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 19,177 4,788 25 0 4,788 - 25 - 84-86 8,156 3,131 38 0 3,131 - 38 - 85-87 40,464 10,121 25 10,609 - 26 - 20,730 - 51 - 86-88 54,117 13,788 25 10,609 - 20 - 24,396 - 45 - 87-89 55,147 13,159 24 8,973 - 16 - 22,132 - 40 - 88-90 25,836 7,297 28 1,636 6 5,662 - 22 - 89-91 14,084 4,384 31 1,636 12 2,748 - 20 - 90-92 11,030 3,811 35 0 3,811 - 35 - 91-93 4,025 1,339 33 0 1,339 - 33 - 92-94 7,512 1,527 20 0 1,527 - 20 - 93-95 8,156 1,527 19 2,347 29 820 10 94-96 6,399 1,096 17 2,347 37 1,252 20 95-97 3,684 749 20 2,347 64 1,599 43 96-98 28,899 5,204 18 0 5,204 - 18 - 97-99 37,266 19,566 53 0 19,566 - 53 - 98-00 52,555 18,817 36 0 18,817 - 36 - 99-01 30,518 14,362 47 0 14,362 - 47 - 00-02 28,765 0 0 0 01-03 15,195 0 0 0 02-04 11,373 0 0 0 03-05 12,250 0 0 0 04-06 76,818 406- 1 - 136 0 542 1 05-07 83,902 406- 0 138 0 544 1 06-08 87,719 3,186 4 248 0 2,938 - 3 - 07-09 18,393 11,212 61 3,796 21 7,417 - 40 - 08-10 12,707 13,631 107 4,675 37 8,956 - 70 - 09-11 1,399 23,363 12,814 916 10,549 - 754 - 10-12 41,208 16,596 40 60,320 146 43,724 106 11-13 67,273 14,792 22 59,439 88 44,647 66 12-14 83,172 367- 0 51,190 62 51,557 62 13-15 60,636 27,086 45 6,229 10 20,856 - 34 - 14-16 118,221 51,867 44 6,229 5 45,637 - 39 - 15-17 153,864 67,665 44 6,400 4 61,265 - 40 - 16-18 164,401 72,381 44 170 0 72,211 - 44 - 17-19 117,014 52,316 45 170 0 52,146 - 45 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-64 Attachment C J. Spanos, Avista Page 424 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 361.00 STRUCTURES AND IMPROVEMENTS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 66,948 47,146 70 2,479 4 44,668 - 67 - 19-21 45,171 14,124 31 2,479 5 11,645 - 26 - FIVE-YEAR AVERAGE 17-21 74,714 36,666 49 1,589 2 35,076 - 47 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-65 Attachment C J. Spanos, Avista Page 425 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 362.00 STATION EQUIPMENT SUMMARY OF BOOK SALVAGE 1983 406,954 88,856 22 260,647 64 171,791 42 1984 347,555 107,234 31 179,060 52 71,826 21 1985 207,925 87,452 42 125,051 60 37,599 18 1986 255,441 136,943 54 97,123 38 39,820 - 16 - 1987 820,355 187,449 23 237,854 29 50,405 6 1988 793,522 216,863 27 189,059 24 27,804 - 4 - 1989 351,587 84,711 24 256,520 73 171,809 49 1990 119,621 39,646 33 96,649 81 57,003 48 1991 653,121 262,731 40 109,065 17 153,666 - 24 - 1992 52,142 23,113 44 123,824 237 100,711 193 1993 230,035 56,476 25 306,263 133 249,787 109 1994 905,282 172,358 19 275,433 30 103,075 11 1995 640,315 138,016 22 150,779 24 12,763 2 1996 313,128 71,865 23 79,896 26 8,031 3 1997 1,263,920 311,299 25 135,655 11 175,644 - 14 - 1998 1,810,877 311,997 17 128,242 7 183,755 - 10 - 1999 833,837 134,383 16 189,891 23 55,509 7 2000 433,469 194,376 45 162,507 37 31,869 - 7 - 2001 199,541 171,788 86 135,462 68 36,327 - 18 - 2002 830,271 127,171 15 120,804 15 6,367 - 1 - 2003 577,119 162,114 28 139,112 24 23,002 - 4 - 2004 171,161 102,251 60 116,498 68 14,247 8 2005 886,336 39,987 5 48,488 5 8,502 1 2006 676,720 142,389 21 205,402 30 63,013 9 2007 568,908 47,993 8 118,520 21 70,527 12 2008 459,094 95,938 21 99,609 22 3,671 1 2009 465,752 95,246 20 185,628 40 90,382 19 2010 969,057 135,205 14 121,762 13 13,443 - 1 - 2011 2,542,957 315,961 12 171,265 7 144,695 - 6 - 2012 1,949,860 158,474 8 213,420 11 54,946 3 2013 1,660,668 41,464 2 0 41,464 - 2 - 2014 709,593 122,669 - 17 - 10,343 1 133,013 19 2015 563,512 911,366 162 181,590 32 729,776 - 130 - 2016 2,851,616 1,802,674 63 50,363 2 1,752,311 - 61 - 2017 2,399,757 94,438 4 64,116 3 30,322 - 1 - 2018 1,909,532 165,819 9 74,323 4 91,496 - 5 - 2019 690,631 372,496 54 152,177 22 220,319 - 32 - 2020 297,345 178,560 60 137,183 46 41,377 - 14 - 2021 792,232 65,593 8 15,843 2 49,751 - 6 - TOTAL 32,610,748 7,730,026 24 5,465,426 17 2,264,600 - 7 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-66 Attachment C J. Spanos, Avista Page 426 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 362.00 STATION EQUIPMENT SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 320,811 94,514 29 188,253 59 93,739 29 84-86 270,307 110,543 41 133,745 49 23,202 9 85-87 427,907 137,281 32 153,343 36 16,061 4 86-88 623,106 180,418 29 174,679 28 5,740- 1 - 87-89 655,155 163,008 25 227,811 35 64,803 10 88-90 421,577 113,740 27 180,743 43 67,003 16 89-91 374,776 129,029 34 154,078 41 25,049 7 90-92 274,961 108,497 39 109,846 40 1,349 0 91-93 311,766 114,107 37 179,717 58 65,611 21 92-94 395,820 83,982 21 235,173 59 151,191 38 93-95 591,877 122,283 21 244,158 41 121,875 21 94-96 619,575 127,413 21 168,703 27 41,290 7 95-97 739,121 173,727 24 122,110 17 51,617- 7 - 96-98 1,129,308 231,720 21 114,598 10 117,123- 10 - 97-99 1,302,878 252,560 19 151,263 12 101,297- 8 - 98-00 1,026,061 213,585 21 160,214 16 53,372- 5 - 99-01 488,949 166,849 34 162,620 33 4,229- 1 - 00-02 487,760 164,445 34 139,591 29 24,854- 5 - 01-03 535,644 153,691 29 131,792 25 21,899- 4 - 02-04 526,184 130,512 25 125,471 24 5,041- 1 - 03-05 544,872 101,450 19 101,366 19 85- 0 04-06 578,072 94,876 16 123,463 21 28,587 5 05-07 710,654 76,790 11 124,137 17 47,347 7 06-08 568,240 95,440 17 141,177 25 45,737 8 07-09 497,918 79,726 16 134,586 27 54,860 11 08-10 631,301 108,796 17 135,666 21 26,870 4 09-11 1,325,922 182,137 14 159,552 12 22,586- 2 - 10-12 1,820,625 203,213 11 168,816 9 34,398- 2 - 11-13 2,051,162 171,966 8 128,228 6 43,738- 2 - 12-14 1,440,040 25,756 2 74,588 5 48,832 3 13-15 977,924 276,720 28 63,978 7 212,742- 22 - 14-16 1,374,907 863,790 63 80,765 6 783,025- 57 - 15-17 1,938,295 936,159 48 98,690 5 837,470- 43 - 16-18 2,386,968 687,644 29 62,934 3 624,709- 26 - 17-19 1,666,640 210,918 13 96,872 6 114,046- 7 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-67 Attachment C J. Spanos, Avista Page 427 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 362.00 STATION EQUIPMENT SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 965,836 238,958 25 121,228 13 117,731- 12 - 19-21 593,403 205,550 35 101,734 17 103,816- 17 - FIVE-YEAR AVERAGE 17-21 1,217,900 175,381 14 88,728 7 86,653- 7 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-68 Attachment C J. Spanos, Avista Page 428 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 364.00 POLES, TOWERS AND FIXTURES SUMMARY OF BOOK SALVAGE 1983 374,004 82,563 22 257,969 69 175,406 47 1984 505,698 155,953 31 291,573 58 135,620 27 1985 524,189 220,471 42 218,113 42 2,358 - 0 1986 642,572 345,961 54 219,709 34 126,252 - 20 - 1987 442,355 101,141 23 297,580 67 196,439 44 1988 443,166 121,116 27 112,589 25 8,527 - 2 - 1989 319,768 59,984 19 178,482 56 118,498 37 1990 356,153 118,039 33 160,152 45 42,113 12 1991 350,257 140,144 40 93,255 27 46,889 - 13 - 1992 366,017 162,243 44 173,192 47 10,949 3 1993 370,646 90,997 25 237,734 64 146,737 40 1994 436,978 83,197 19 240,938 55 157,741 36 1995 601,568 129,665 22 333,351 55 203,686 34 1996 887,940 203,787 23 226,563 26 22,776 3 1997 829,253 204,242 25 216,465 26 12,223 1 1998 770,737 132,791 17 349,964 45 217,173 28 1999 730,838 202,595 28 321,996 44 119,401 16 2000 670,237 329,601 49 275,561 41 54,040 - 8 - 2001 306,069 - 291,299 95 - 229,700 75 - 61,599 - 20 2002 96,675 215,642 223 204,845 212 10,796 - 11 - 2003 130,002 274,894 211 235,889 181 39,004 - 30 - 2004 146,301 87,538 60 99,735 68 12,197 8 2005 121,328 286,651 236 59,885 49 226,766 - 187 - 2006 447,952 596,167 133 186,671 42 409,496 - 91 - 2007 245,704 466,606 190 177,048 72 289,558 - 118 - 2008 294,588 1,113,938 378 177,066 60 936,872 - 318 - 2009 226,413 1,364,944 603 188,974 83 1,175,970 - 519 - 2010 312,503 810,100 259 255,801 82 554,299 - 177 - 2011 494,267 1,980,755 401 263,224 53 1,717,532 - 347 - 2012 1,551,487 1,402,781 90 74,766 5 1,328,016 - 86 - 2013 1,063,036 1,296,893 122 9,738 1 1,287,155 - 121 - 2014 1,339,893 1,586,086 118 7,310 1 1,578,776 - 118 - 2015 710,655 1,876,947 264 30,068 4 1,846,879 - 260 - 2016 522,626 146,287 28 0 146,287 - 28 - 2017 1,253,983 339,035 27 17,625 1 321,409 - 26 - 2018 1,525,305 1,434,391 94 3,822 0 1,430,570 - 94 - 2019 1,422,788 563,089 40 12,076 1 551,013 - 39 - 2020 1,270,839 311,060 24 727 0 310,333 - 24 - 2021 1,512,289 683,507 45 1,086 0 682,421 - 45 - TOTAL 24,004,942 20,013,099 83 6,441,241 27 13,571,858 - 57 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-69 Attachment C J. Spanos, Avista Page 429 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 364.00 POLES, TOWERS AND FIXTURES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 467,964 152,996 33 255,885 55 102,889 22 84-86 557,486 240,795 43 243,132 44 2,337 0 85-87 536,372 222,524 41 245,134 46 22,610 4 86-88 509,364 189,406 37 209,959 41 20,553 4 87-89 401,763 94,080 23 196,217 49 102,137 25 88-90 373,029 99,713 27 150,408 40 50,695 14 89-91 342,059 106,056 31 143,963 42 37,907 11 90-92 357,476 140,142 39 142,200 40 2,058 1 91-93 362,307 131,128 36 168,060 46 36,932 10 92-94 391,214 112,146 29 217,288 56 105,142 27 93-95 469,731 101,286 22 270,674 58 169,388 36 94-96 642,162 138,883 22 266,951 42 128,068 20 95-97 772,920 179,231 23 258,793 33 79,562 10 96-98 829,310 180,273 22 264,331 32 84,057 10 97-99 776,943 179,876 23 296,142 38 116,266 15 98-00 723,937 221,662 31 315,840 44 94,178 13 99-01 365,002 274,498 75 275,752 76 1,254 0 00-02 153,614 278,847 182 236,702 154 42,145 - 27 - 01-03 26,464 - 260,611 985 - 223,478 844 - 37,133 - 140 02-04 124,326 192,691 155 180,157 145 12,535 - 10 - 03-05 132,544 216,361 163 131,836 99 84,524 - 64 - 04-06 238,527 323,452 136 115,430 48 208,022 - 87 - 05-07 271,662 449,808 166 141,201 52 308,607 - 114 - 06-08 329,415 725,570 220 180,262 55 545,308 - 166 - 07-09 255,569 981,829 384 181,029 71 800,800 - 313 - 08-10 277,835 1,096,327 395 207,280 75 889,047 - 320 - 09-11 344,394 1,385,266 402 235,999 69 1,149,267 - 334 - 10-12 786,086 1,397,879 178 197,930 25 1,199,949 - 153 - 11-13 1,036,263 1,560,143 151 115,909 11 1,444,234 - 139 - 12-14 1,318,139 1,428,587 108 30,605 2 1,397,982 - 106 - 13-15 1,037,861 1,586,642 153 15,705 2 1,570,937 - 151 - 14-16 857,725 1,203,106 140 12,459 1 1,190,647 - 139 - 15-17 829,088 787,423 95 15,898 2 771,525 - 93 - 16-18 1,100,638 639,904 58 7,149 1 632,755 - 57 - 17-19 1,400,692 778,838 56 11,174 1 767,664 - 55 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-70 Attachment C J. Spanos, Avista Page 430 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 364.00 POLES, TOWERS AND FIXTURES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 1,406,311 769,514 55 5,541 0 763,972 - 54 - 19-21 1,401,972 519,219 37 4,630 0 514,589 - 37 - FIVE-YEAR AVERAGE 17-21 1,397,041 666,216 48 7,067 1 659,149 - 47 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-71 Attachment C J. Spanos, Avista Page 431 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 365.00 OVERHEAD CONDUCTORS AND DEVICES SUMMARY OF BOOK SALVAGE 1983 163,575 35,680 22 100,137 61 64,457 39 1984 243,384 75,098 31 191,873 79 116,775 48 1985 259,604 109,188 42 157,401 61 48,213 19 1986 551,745 297,311 54 170,466 31 126,845 - 23 - 1987 362,824 82,936 23 235,296 65 152,360 42 1988 412,947 112,863 27 197,409 48 84,546 20 1989 360,920 67,703 19 233,186 65 165,483 46 1990 422,372 139,986 33 191,891 45 51,905 12 1991 306,712 122,721 40 159,449 52 36,728 12 1992 164,949 73,116 44 107,573 65 34,457 21 1993 223,354 54,836 25 233,101 104 178,265 80 1994 198,925 37,874 19 286,804 144 248,930 125 1995 191,011 41,171 22 321,185 168 280,014 147 1996 209,830 48,157 23 53,539 26 5,382 3 1997 305,524 75,250 25 217,874 71 142,624 47 1998 337,431 58,136 17 232,208 69 174,072 52 1999 491,689 137,601 28 308,574 63 170,973 35 2000 303,173 315,862 104 264,074 87 51,788 - 17 - 2001 136,226 279,156 205 220,125 162 59,031 - 43 - 2002 125,367 206,653 165 196,306 157 10,346 - 8 - 2003 150,569 263,435 175 226,056 150 37,379 - 25 - 2004 127,427 76,262 60 86,888 68 10,626 8 2005 59,925 168,646 281 58,793 98 109,853 - 183 - 2006 312,278 400,030 128 116,061 37 283,970 - 91 - 2007 152,704 380,009 249 169,155 111 210,854 - 138 - 2008 293,842 874,044 297 233,884 80 640,161 - 218 - 2009 244,866 967,898 395 170,316 70 797,582 - 326 - 2010 563,810 1,234,180 219 226,267 40 1,007,913 - 179 - 2011 499,424 1,271,181 255 320,946 64 950,235 - 190 - 2012 427,073 453,643 - 106 - 38,649 9 492,292 115 2013 372 363,780 8,352 355,428 - 2014 204,213 623,617 305 27,575 14 596,043 - 292 - 2015 72,499 1,267,057 35,624 49 1,231,433 - 2016 224,562 139,002 62 0 139,002 - 62 - 2017 168,114 261,924 156 26,939 16 234,984 - 140 - 2018 126,202 245,480 195 48 0 245,433 - 194 - 2019 116,166 369,034 318 40,606 35 328,428 - 283 - 2020 96,581 205,850 213 727 1 205,123 - 212 - 2021 114,645 226,620 198 136 0 226,485 - 198 - TOTAL 9,726,835 11,255,704 116 5,865,491 60 5,390,213 - 55 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-72 Attachment C J. Spanos, Avista Page 432 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 365.00 OVERHEAD CONDUCTORS AND DEVICES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 222,188 73,322 33 149,804 67 76,482 34 84-86 351,578 160,532 46 173,247 49 12,714 4 85-87 391,391 163,145 42 187,721 48 24,576 6 86-88 442,505 164,370 37 201,057 45 36,687 8 87-89 378,897 87,834 23 221,964 59 134,130 35 88-90 398,746 106,851 27 207,495 52 100,645 25 89-91 363,335 110,137 30 194,842 54 84,705 23 90-92 298,011 111,941 38 152,971 51 41,030 14 91-93 231,672 83,558 36 166,708 72 83,150 36 92-94 195,743 55,275 28 209,159 107 153,884 79 93-95 204,430 44,627 22 280,363 137 235,736 115 94-96 199,922 42,401 21 220,509 110 178,109 89 95-97 235,455 54,859 23 197,533 84 142,673 61 96-98 284,262 60,514 21 167,874 59 107,359 38 97-99 378,215 90,329 24 252,885 67 162,556 43 98-00 377,431 170,533 45 268,285 71 97,752 26 99-01 310,363 244,206 79 264,258 85 20,051 6 00-02 188,255 267,223 142 226,835 120 40,388 - 21 - 01-03 137,387 249,748 182 214,162 156 35,585 - 26 - 02-04 134,454 182,116 135 169,750 126 12,366 - 9 - 03-05 112,640 169,448 150 123,912 110 45,535 - 40 - 04-06 166,543 214,979 129 87,247 52 127,732 - 77 - 05-07 174,969 316,228 181 114,669 66 201,559 - 115 - 06-08 252,941 551,361 218 173,033 68 378,328 - 150 - 07-09 230,471 740,650 321 191,118 83 549,532 - 238 - 08-10 367,506 1,025,374 279 210,156 57 815,218 - 222 - 09-11 436,033 1,157,753 266 239,177 55 918,576 - 211 - 10-12 496,769 683,906 138 195,288 39 488,619 - 98 - 11-13 308,957 393,773 127 122,649 40 271,124 - 88 - 12-14 210,553 177,918 85 24,859 12 153,060 - 73 - 13-15 92,362 751,485 814 23,850 26 727,635 - 788 - 14-16 167,092 676,559 405 21,066 13 655,493 - 392 - 15-17 155,059 555,994 359 20,854 13 535,140 - 345 - 16-18 172,960 215,469 125 8,996 5 206,473 - 119 - 17-19 136,828 292,146 214 22,531 16 269,615 - 197 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-73 Attachment C J. Spanos, Avista Page 433 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 365.00 OVERHEAD CONDUCTORS AND DEVICES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 112,983 273,455 242 13,793 12 259,661 - 230 - 19-21 109,131 267,168 245 13,823 13 253,345 - 232 - FIVE-YEAR AVERAGE 17-21 124,342 261,782 211 13,691 11 248,091 - 200 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-74 Attachment C J. Spanos, Avista Page 434 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 366.00 AND 367.00 UNDERGROUND CONDUIT, CONDUCTORS AND DEVICES SUMMARY OF BOOK SALVAGE 1983 21,661 26,138 121 189,828 876 163,690 756 1984 340,978 105,172 31 14,944 4 90,228 - 26 - 1985 326,613 137,371 42 18,096 6 119,275 - 37 - 1986 387,549 207,216 53 26,261 7 180,955 - 47 - 1987 275,999 63,382 23 45,070 16 18,312 - 7 - 1988 270,564 73,969 27 10,191 4 63,778 - 24 - 1989 637,197 119,529 19 30,840 5 88,689 - 14 - 1990 405,261 134,316 33 18,614 5 115,702 - 29 - 1991 440,248 176,151 40 19,732 4 156,419 - 36 - 1992 849,221 376,430 44 42,598 5 333,832 - 39 - 1993 938,848 230,497 25 83,909 9 146,588 - 16 - 1994 2,691,246 512,390 19 126,441 5 385,949 - 14 - 1995 1,548,015 333,667 22 122,661 8 211,006 - 14 - 1996 1,422,577 326,489 23 362,979 26 36,490 3 1997 1,149,848 283,204 25 78,293 7 204,911 - 18 - 1998 1,515,425 261,093 17 96,715 6 164,378 - 11 - 1999 2,267,633 226,617 10 112,607 5 114,010 - 5 - 2000 546,679 115,266 21 96,368 18 18,899 - 3 - 2001 277,497 101,872 37 80,330 29 21,542 - 8 - 2002 373,819 75,413 20 71,637 19 3,776 - 1 - 2003 365,379 96,134 26 82,494 23 13,640 - 4 - 2004 419,860 251,186 60 286,184 68 34,999 8 2005 268,987 167,199 62 82,323 31 84,876 - 32 - 2006 789,980 372,784 47 190,956 24 181,828 - 23 - 2007 605,184 276,957 46 154,026 25 122,931 - 20 - 2008 625,378 323,800 52 148,358 24 175,443 - 28 - 2009 558,615 358,470 64 143,571 26 214,899 - 38 - 2010 548,810 242,442 44 75,008 14 167,434 - 31 - 2011 500,083 457,584 92 808,528 162 350,944 70 2012 813,009 256,542 32 129,442 16 127,100 - 16 - 2013 538,482 249,983 46 1,107 0 248,876 - 46 - 2014 395,816 236,724 60 2 0 236,722 - 60 - 2015 202,777 1,062,849 524 21,097 10 1,041,752 - 514 - 2016 240,914 1,173,009 487 0 1,173,009 - 487 - 2017 686,535 79,756 12 0 79,756 - 12 - 2018 384,761 53,410 14 0 53,410 - 14 - 2019 220,166 94,233 43 133 0 94,100 - 43 - 2020 308,307 50,793 16 0 50,793 - 16 - 2021 300,457 78,061 26 0 78,061 - 26 - TOTAL 25,460,380 9,768,098 38 3,771,342 15 5,996,756 - 24 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-75 Attachment C J. Spanos, Avista Page 435 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 366.00 AND 367.00 UNDERGROUND CONDUIT, CONDUCTORS AND DEVICES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 229,751 89,560 39 74,289 32 15,271 - 7 - 84-86 351,713 149,920 43 19,767 6 130,153 - 37 - 85-87 330,054 135,990 41 29,809 9 106,181 - 32 - 86-88 311,371 114,856 37 27,174 9 87,682 - 28 - 87-89 394,587 85,627 22 28,700 7 56,926 - 14 - 88-90 437,674 109,271 25 19,882 5 89,390 - 20 - 89-91 494,235 143,332 29 23,062 5 120,270 - 24 - 90-92 564,910 228,966 41 26,981 5 201,984 - 36 - 91-93 742,772 261,026 35 48,746 7 212,280 - 29 - 92-94 1,493,105 373,106 25 84,316 6 288,790 - 19 - 93-95 1,726,036 358,851 21 111,004 6 247,848 - 14 - 94-96 1,887,279 390,849 21 204,027 11 186,822 - 10 - 95-97 1,373,480 314,453 23 187,978 14 126,476 - 9 - 96-98 1,362,617 290,262 21 179,329 13 110,933 - 8 - 97-99 1,644,302 256,971 16 95,872 6 161,100 - 10 - 98-00 1,443,246 200,992 14 101,896 7 99,096 - 7 - 99-01 1,030,603 147,918 14 96,435 9 51,484 - 5 - 00-02 399,332 97,517 24 82,778 21 14,739 - 4 - 01-03 338,898 91,140 27 78,154 23 12,986 - 4 - 02-04 386,353 140,911 36 146,772 38 5,861 2 03-05 351,409 171,506 49 150,334 43 21,173 - 6 - 04-06 492,942 263,723 53 186,488 38 77,235 - 16 - 05-07 554,717 272,314 49 142,435 26 129,879 - 23 - 06-08 673,514 324,514 48 164,447 24 160,067 - 24 - 07-09 596,392 319,742 54 148,652 25 171,091 - 29 - 08-10 577,601 308,237 53 122,312 21 185,925 - 32 - 09-11 535,836 352,832 66 342,369 64 10,463 - 2 - 10-12 620,634 318,856 51 337,659 54 18,803 3 11-13 617,191 321,370 52 313,025 51 8,344 - 1 - 12-14 582,436 247,750 43 43,517 7 204,233 - 35 - 13-15 379,025 516,519 136 7,402 2 509,117 - 134 - 14-16 279,836 824,194 295 7,033 3 817,161 - 292 - 15-17 376,742 771,871 205 7,032 2 764,839 - 203 - 16-18 437,403 435,392 100 0 435,392 - 100 - 17-19 430,487 75,800 18 44 0 75,755 - 18 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-76 Attachment C J. Spanos, Avista Page 436 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 366.00 AND 367.00 UNDERGROUND CONDUIT, CONDUCTORS AND DEVICES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 304,411 66,145 22 44 0 66,101 - 22 - 19-21 276,310 74,363 27 44 0 74,318 - 27 - FIVE-YEAR AVERAGE 17-21 380,045 71,251 19 27 0 71,224 - 19 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-77 Attachment C J. Spanos, Avista Page 437 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 368.00 LINE TRANSFORMERS SUMMARY OF BOOK SALVAGE 1983 552,785 120,665 22 66,798 12 53,867 - 10 - 1984 842,194 259,750 31 188,066 22 71,684 - 9 - 1985 573,594 241,250 42 170,605 30 70,645 - 12 - 1986 1,041,100 560,385 54 193,221 19 367,164 - 35 - 1987 617,403 140,924 23 73,002 12 67,922 - 11 - 1988 604,312 165,207 27 80,085 13 85,122 - 14 - 1989 627,212 117,655 19 249,033 40 131,378 21 1990 523,294 173,435 33 73,822 14 99,613 - 19 - 1991 600,628 240,321 40 51,513 9 188,808 - 31 - 1992 745,819 330,596 44 26,651 4 303,945 - 41 - 1993 724,649 177,909 25 36,395 5 141,514 - 20 - 1994 588,290 112,005 19 54,859 9 57,146 - 10 - 1995 775,265 167,104 22 452,923 58 285,819 37 1996 714,361 163,950 23 182,273 26 18,323 3 1997 893,941 220,175 25 235,485 26 15,310 2 1998 850,524 146,537 17 74,759 9 71,778 - 8 - 1999 714,259 99,557 14 310,693 43 211,136 30 2000 998,381 318,031 32 265,888 27 52,143 - 5 - 2001 836,857 281,073 34 221,637 26 59,437 - 7 - 2002 533,011 208,072 39 197,654 37 10,417 - 2 - 2003 617,809 265,244 43 227,609 37 37,635 - 6 - 2004 752,143 449,706 60 512,365 68 62,659 8 2005 898,859 16,979 - 2 - 19,096 2 36,075 4 2006 1,423,953 80,863 - 6 - 19,541 1 100,404 7 2007 1,249,685 294,653 - 24 - 44,778 4 339,431 27 2008 1,395,472 66,154 - 5 - 24,337 2 90,491 6 2009 2,091,011 354,591 17 37,280 2 317,312 - 15 - 2010 1,944,379 493,691 25 85,850 4 407,841 - 21 - 2011 2,970,698 40,168 - 1 - 48,056 2 88,224 3 2012 3,356,824 396,162 - 12 - 42,894 1 439,056 13 2013 1,938,563 92,323 - 5 - 2,985 0 95,309 5 2014 134,901 3,968 - 3 - 0 3,968 3 2015 132,263 318,080 240 4,797 4 313,283 - 237 - 2016 123,226 685,830 557 0 685,830 - 557 - 2017 212,726 42,570 20 19,349 9 23,221 - 11 - 2018 272,196 73,694 27 194 0 73,500 - 27 - 2019 190,179 186,562 98 10,046 5 176,515 - 93 - 2020 157,661 1,219 1 0 1,219 - 1 - 2021 203,249 183,074 90 874,281 430 691,207 340 TOTAL 34,423,676 6,307,590 18 5,178,820 15 1,128,770 - 3 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-78 Attachment C J. Spanos, Avista Page 438 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 368.00 LINE TRANSFORMERS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 656,191 207,222 32 141,823 22 65,399 - 10 - 84-86 818,963 353,795 43 183,964 22 169,831 - 21 - 85-87 744,032 314,186 42 145,609 20 168,577 - 23 - 86-88 754,272 288,839 38 115,436 15 173,403 - 23 - 87-89 616,309 141,262 23 134,040 22 7,222 - 1 - 88-90 584,939 152,099 26 134,313 23 17,786 - 3 - 89-91 583,711 177,137 30 124,789 21 52,348 - 9 - 90-92 623,247 248,117 40 50,662 8 197,455 - 32 - 91-93 690,365 249,609 36 38,186 6 211,422 - 31 - 92-94 686,253 206,837 30 39,302 6 167,535 - 24 - 93-95 696,068 152,339 22 181,392 26 29,053 4 94-96 692,639 147,686 21 230,018 33 82,332 12 95-97 794,523 183,743 23 290,227 37 106,484 13 96-98 819,609 176,887 22 164,172 20 12,715 - 2 - 97-99 819,575 155,423 19 206,979 25 51,556 6 98-00 854,388 188,042 22 217,113 25 29,072 3 99-01 849,832 232,887 27 266,073 31 33,185 4 00-02 789,416 269,059 34 228,393 29 40,666 - 5 - 01-03 662,559 251,463 38 215,633 33 35,830 - 5 - 02-04 634,321 307,674 49 312,543 49 4,869 1 03-05 756,270 232,657 31 253,023 33 20,366 3 04-06 1,024,985 117,288 11 183,667 18 66,379 6 05-07 1,190,832 130,832- 11 - 27,805 2 158,637 13 06-08 1,356,370 147,224- 11 - 29,552 2 176,775 13 07-09 1,578,723 2,072- 0 35,465 2 37,537 2 08-10 1,810,287 260,709 14 49,155 3 211,554 - 12 - 09-11 2,335,363 269,371 12 57,062 2 212,310 - 9 - 10-12 2,757,300 19,120 1 58,933 2 39,813 1 11-13 2,755,362 176,218- 6 - 31,312 1 207,529 8 12-14 1,810,096 164,151- 9 - 15,293 1 179,444 10 13-15 735,242 73,930 10 2,594 0 71,335 - 10 - 14-16 130,130 333,314 256 1,599 1 331,715 - 255 - 15-17 156,072 348,827 224 8,049 5 340,778 - 218 - 16-18 202,716 267,364 132 6,514 3 260,850 - 129 - 17-19 225,034 100,942 45 9,863 4 91,079 - 40 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-79 Attachment C J. Spanos, Avista Page 439 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 368.00 LINE TRANSFORMERS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 206,678 87,158 42 3,413 2 83,745 - 41 - 19-21 183,696 123,618 67 294,776 160 171,158 93 FIVE-YEAR AVERAGE 17-21 207,202 97,424 47 180,774 87 83,351 40 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-80 Attachment C J. Spanos, Avista Page 440 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 369.10, 369.20 AND 369.30 UNDERGROUND AND OVERHEAD SERVICES SUMMARY OF BOOK SALVAGE 1983 88,578 19,434 22 10,796 12 8,638 - 10 - 1984 94,280 29,043 31 4,868 5 24,175 - 26 - 1985 117,469 49,406 42 4,990 4 44,416 - 38 - 1986 111,532 59,462 53 18,583 17 40,879 - 37 - 1987 129,889 29,668 23 20,939 16 8,729 - 7 - 1988 128,304 35,074 27 3,935 3 31,139 - 24 - 1989 303,351 56,904 19 3,207 1 53,697 - 18 - 1990 147,439 48,865 33 87,822 60 38,957 26 1991 63,490 25,403 40 4,149 7 21,254 - 33 - 1992 83,581 37,048 44 22,807 27 14,241 - 17 - 1993 52,749 12,950 25 59,271 112 46,321 88 1994 66,361 12,635 19 32,299 49 19,664 30 1995 63,584 13,705 22 96,170 151 82,465 130 1996 105,424 24,195 23 26,900 26 2,705 3 1997 113,339 27,915 25 71,350 63 43,435 38 1998 196,924 33,928 17 38,855 20 4,927 3 1999 135,292 82,917 61 96,217 71 13,300 10 2000 96,211 98,490 102 82,342 86 16,148 - 17 - 2001 59,445 87,045 146 68,638 115 18,407 - 31 - 2002 63,820 64,437 101 61,211 96 3,226 - 5 - 2003 79,697 82,142 103 70,487 88 11,655 - 15 - 2004 78,561 46,989 60 53,536 68 6,547 8 2005 89,912 223,399 248 83,844 93 139,555 - 155 - 2006 142,244 196,928 138 101,137 71 95,791 - 67 - 2007 130,868 191,748 147 108,433 83 83,315 - 64 - 2008 101,423 278,992 275 68,172 67 210,820 - 208 - 2009 76,668 257,495 336 50,942 66 206,553 - 269 - 2010 83,212 210,961 254 117,312 141 93,650 - 113 - 2011 74,876 173,099 231 178,769 239 5,670 8 2012 91,206 121,400 133 11,986 13 109,415 - 120 - 2013 6,504 56,638 871 161 2 56,477 - 868 - 2014 49,347 183,934 373 0 183,934 - 373 - 2015 50,621 84,475 167 1,093 2 83,381 - 165 - 2016 72,338 1,247 2 0 1,247 - 2 - 2017 48,412 2,908 6 3,159 7 250 1 2018 47,102 194 0 0 194 - 0 2019 41,267 2,459 6 0 2,459 - 6 - 2020 63,421 1,092 2 0 1,092 - 2 - 2021 121,631 4,379 4 0 4,379 - 4 - TOTAL 3,670,373 2,969,002 81 1,664,379 45 1,304,624 - 36 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-81 Attachment C J. Spanos, Avista Page 441 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 369.10, 369.20 AND 369.30 UNDERGROUND AND OVERHEAD SERVICES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 100,109 32,628 33 6,885 7 25,743 - 26 - 84-86 107,760 45,970 43 9,480 9 36,490 - 34 - 85-87 119,630 46,179 39 14,837 12 31,341 - 26 - 86-88 123,242 41,401 34 14,486 12 26,916 - 22 - 87-89 187,181 40,549 22 9,360 5 31,188 - 17 - 88-90 193,031 46,948 24 31,655 16 15,293 - 8 - 89-91 171,427 43,724 26 31,726 19 11,998 - 7 - 90-92 98,170 37,105 38 38,259 39 1,154 1 91-93 66,607 25,134 38 28,742 43 3,609 5 92-94 67,564 20,878 31 38,126 56 17,248 26 93-95 60,898 13,097 22 62,580 103 49,483 81 94-96 78,457 16,845 21 51,790 66 34,945 45 95-97 94,116 21,938 23 64,807 69 42,868 46 96-98 138,562 28,679 21 45,702 33 17,022 12 97-99 148,518 48,253 32 68,807 46 20,554 14 98-00 142,809 71,778 50 72,471 51 693 0 99-01 96,983 89,484 92 82,399 85 7,085 - 7 - 00-02 73,159 83,324 114 70,730 97 12,594 - 17 - 01-03 67,654 77,875 115 66,779 99 11,096 - 16 - 02-04 74,026 64,523 87 61,745 83 2,778 - 4 - 03-05 82,723 117,510 142 69,289 84 48,221 - 58 - 04-06 103,572 155,772 150 79,506 77 76,266 - 74 - 05-07 121,008 204,025 169 97,804 81 106,220 - 88 - 06-08 124,845 222,556 178 92,580 74 129,975 - 104 - 07-09 102,987 242,745 236 75,849 74 166,896 - 162 - 08-10 87,101 249,149 286 78,808 90 170,341 - 196 - 09-11 78,252 213,852 273 115,674 148 98,178 - 125 - 10-12 83,098 168,487 203 102,689 124 65,798 - 79 - 11-13 57,528 117,046 203 63,639 111 53,407 - 93 - 12-14 49,019 120,658 246 4,049 8 116,609 - 238 - 13-15 35,491 108,349 305 418 1 107,931 - 304 - 14-16 57,435 89,885 156 364 1 89,521 - 156 - 15-17 57,123 29,543 52 1,417 2 28,126 - 49 - 16-18 55,950 1,450 3 1,053 2 397 - 1 - 17-19 45,594 1,854 4 1,053 2 801 - 2 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-82 Attachment C J. Spanos, Avista Page 442 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 369.10, 369.20 AND 369.30 UNDERGROUND AND OVERHEAD SERVICES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 50,597 1,248 2 0 1,248 - 2 - 19-21 75,440 2,643 4 0 2,643 - 4 - FIVE-YEAR AVERAGE 17-21 64,367 2,207 3 632 1 1,575 - 2 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-83 Attachment C J. Spanos, Avista Page 443 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 370.10, 370.30 AND 370.40 METERS SUMMARY OF BOOK SALVAGE 1983 496,701 108,425 22 11,254 2 97,171 - 20 - 1984 123,787 38,151 31 6,734 5 31,417 - 25 - 1985 38,195 16,064 42 16 - 0 16,080 - 42 - 1986 366,801 0 5,865 2 5,865 2 1987 104,873 0 3,394 3 3,394 3 1988 78,770 0 3,602 5 3,602 5 1989 43,545 8,168 19 4,029 9 4,139 - 10 - 1990 56,298 18,659 33 5,344 9 13,315 - 24 - 1991 31,467 12,591 40 2,798 9 9,793 - 31 - 1992 148 66 45 491 332 425 287 1993 127 31 24 475 374 444 350 1994 19 4 21 4,486 4,482 1995 267,982 57,762 22 45,907 17 11,855 - 4 - 1996 366,547 84,125 23 93,527 26 9,402 3 1997 199,959 49,249 25 31,901 16 17,348 - 9 - 1998 204,169 35,176 17 9,661 5 25,515 - 12 - 1999 576,124 23,781 4 42,104 7 18,323 3 2000 600,705 43,098 7 36,032 6 7,066 - 1 - 2001 404,457 38,090 9 30,035 7 8,055 - 2 - 2002 318,412 28,197 9 26,785 8 1,412 - 0 2003 403,219 35,945 9 30,845 8 5,100 - 1 - 2004 368,406 220,335 60 251,035 68 30,700 8 2005 2,664,407 5,543 - 0 0 5,543 0 2006 1,906,944 14,941 1 0 14,941 - 1 - 2007 2,421,734 7,761 - 0 762 0 8,523 0 2008 489,066 76,904 16 101,157 21 24,253 5 2009 939,786 868 0 6,833 1 5,965 1 2010 300,610 0 0 0 2011 1,033,158 2,624 - 0 9,177 1 11,801 1 2012 606,236 6,424 1 0 6,424 - 1 - 2013 661,148 4,680 1 0 4,680 - 1 - 2014 769,440 13,759 - 2 - 1 0 13,760 2 2015 42,081 90,127 214 1,723 4 88,404 - 210 - 2016 78,259 189,215 242 0 189,215 - 242 - 2017 2,531,874 0 0 0 2018 831,066 0 0 0 2019 15,567,087 210 - 0 0 210 0 2020 12,365,355 0 0 0 2021 298,687 43,535 - 15 - 0 43,535 15 TOTAL 48,557,649 1,127,644 2 765,942 2 361,702 - 1 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-84 Attachment C J. Spanos, Avista Page 444 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 370.10, 370.30 AND 370.40 METERS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 219,561 54,213 25 5,991 3 48,223- 22 - 84-86 176,261 18,072 10 4,194 2 13,877- 8 - 85-87 169,956 5,355 3 3,081 2 2,274- 1 - 86-88 183,481 0 4,287 2 4,287 2 87-89 75,729 2,723 4 3,675 5 952 1 88-90 59,538 8,942 15 4,325 7 4,617- 8 - 89-91 43,770 13,139 30 4,057 9 9,082- 21 - 90-92 29,304 10,439 36 2,878 10 7,561- 26 - 91-93 10,581 4,229 40 1,255 12 2,975- 28 - 92-94 98 34 34 1,817 1,784 93-95 89,376 19,266 22 16,956 19 2,310- 3 - 94-96 211,516 47,297 22 47,973 23 676 0 95-97 278,163 63,712 23 57,112 21 6,600- 2 - 96-98 256,892 56,183 22 45,030 18 11,154- 4 - 97-99 326,751 36,069 11 27,889 9 8,180- 3 - 98-00 460,333 34,018 7 29,266 6 4,753- 1 - 99-01 527,095 34,990 7 36,057 7 1,067 0 00-02 441,191 36,462 8 30,951 7 5,511- 1 - 01-03 375,363 34,077 9 29,222 8 4,856- 1 - 02-04 363,346 94,826 26 102,888 28 8,063 2 03-05 1,145,344 83,579 7 93,960 8 10,381 1 04-06 1,646,586 76,578 5 83,678 5 7,101 0 05-07 2,331,028 546 0 254 0 292- 0 06-08 1,605,915 28,028 2 33,973 2 5,945 0 07-09 1,283,529 23,337 2 36,251 3 12,914 1 08-10 576,487 25,924 4 35,997 6 10,073 2 09-11 757,851 585 - 0 5,337 1 5,922 1 10-12 646,668 1,267 0 3,059 0 1,792 0 11-13 766,847 2,827 0 3,059 0 232 0 12-14 678,941 885 - 0 0 885 0 13-15 490,890 27,016 6 575 0 26,441- 5 - 14-16 296,593 88,528 30 575 0 87,953- 30 - 15-17 884,071 93,114 11 574 0 92,540- 10 - 16-18 1,147,066 63,072 5 0 63,072- 5 - 17-19 6,310,009 70 - 0 0 70 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-85 Attachment C J. Spanos, Avista Page 445 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 370.10, 370.30 AND 370.40 METERS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 9,587,836 70 - 0 0 70 0 19-21 9,410,376 14,582 - 0 0 14,582 0 FIVE-YEAR AVERAGE 17-21 6,318,814 8,749 - 0 0 8,749 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-86 Attachment C J. Spanos, Avista Page 446 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 373.10, 373.20, 373.30, 373.40 AND 373.50 STREET LIGHTING AND SIGNAL SYSTEMS SUMMARY OF BOOK SALVAGE 1983 928,058 201,154 22 34,518 4 166,636 - 18 - 1984 270,823 83,519 31 16,593 6 66,926 - 25 - 1985 466,915 196,404 42 14,841 3 181,563 - 39 - 1986 353,680 191,000 54 14,929 4 176,071 - 50 - 1987 186,256 42,479 23 27,106 15 15,373 - 8 - 1988 100,778 27,586 27 21,850 22 5,736 - 6 - 1989 71,146 13,346 19 20,465 29 7,119 10 1990 81,080 26,872 33 24,361 30 2,511 - 3 - 1991 88,279 35,322 40 21,881 25 13,441 - 15 - 1992 90,559 40,141 44 31,464 35 8,677 - 10 - 1993 85,693 21,038 25 30,547 36 9,509 11 1994 133,446 25,411 19 37,239 28 11,828 9 1995 145,300 31,319 22 20,196 14 11,123 - 8 - 1996 94,240 21,628 23 24,046 26 2,418 3 1997 129,716 31,948 25 21,061 16 10,887 - 8 - 1998 98,349 16,944 17 47,409 48 30,465 31 1999 140,408 25,690 18 30,801 22 5,111 4 2000 101,174 31,528 31 26,359 26 5,169 - 5 - 2001 71,594 27,864 39 21,972 31 5,892 - 8 - 2002 73,730 20,627 28 19,595 27 1,033 - 1 - 2003 87,292 26,295 30 22,564 26 3,731 - 4 - 2004 64,238 38,462 60 43,821 68 5,359 8 2005 30,975 69,534 224 32,864 106 36,671 - 118 - 2006 217,118 132,311 61 25,823 12 106,488 - 49 - 2007 139,815 111,113 79 41,454 30 69,659 - 50 - 2008 89,849 94,127 105 9,829 11 84,298 - 94 - 2009 105,899 167,537 158 18,516 17 149,021 - 141 - 2010 78,012 108,628 139 32,827 42 75,801 - 97 - 2011 90,626 82,418 91 14,610 16 67,808 - 75 - 2012 118,828 70,125 59 2,080 2 68,045 - 57 - 2013 83,957 67,781 81 3,050 4 64,731 - 77 - 2014 121,568 59,265 49 0 59,265 - 49 - 2015 441,736 74,384 17 0 74,384 - 17 - 2016 1,363,099 504 0 0 504 - 0 2017 3,130,688 1,321 0 0 1,321 - 0 2018 1,447,568 0 0 0 2019 857,355 32,912 4 0 32,912 - 4 - 2020 703,381 0 0 0 2021 581,609 4,744 1 0 4,744 - 1 - TOTAL 13,464,836 2,253,281 17 754,670 6 1,498,612 - 11 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-87 Attachment C J. Spanos, Avista Page 447 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 373.10, 373.20, 373.30, 373.40 AND 373.50 STREET LIGHTING AND SIGNAL SYSTEMS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 555,265 160,359 29 21,984 4 138,375 - 25 - 84-86 363,806 156,974 43 15,454 4 141,520 - 39 - 85-87 335,617 143,294 43 18,959 6 124,336 - 37 - 86-88 213,571 87,022 41 21,295 10 65,727 - 31 - 87-89 119,393 27,804 23 23,140 19 4,663 - 4 - 88-90 84,335 22,601 27 22,225 26 376 - 0 89-91 80,168 25,180 31 22,236 28 2,944 - 4 - 90-92 86,639 34,112 39 25,902 30 8,210 - 9 - 91-93 88,177 32,167 36 27,964 32 4,203 - 5 - 92-94 103,233 28,863 28 33,083 32 4,220 4 93-95 121,480 25,923 21 29,327 24 3,405 3 94-96 124,329 26,119 21 27,160 22 1,041 1 95-97 123,085 28,298 23 21,768 18 6,531 - 5 - 96-98 107,435 23,507 22 30,839 29 7,332 7 97-99 122,825 24,861 20 33,090 27 8,230 7 98-00 113,310 24,721 22 34,856 31 10,136 9 99-01 104,392 28,361 27 26,377 25 1,983 - 2 - 00-02 82,166 26,673 32 22,642 28 4,031 - 5 - 01-03 77,539 24,929 32 21,377 28 3,552 - 5 - 02-04 75,087 28,461 38 28,660 38 198 0 03-05 60,835 44,764 74 33,083 54 11,681 - 19 - 04-06 104,110 80,102 77 34,169 33 45,933 - 44 - 05-07 129,302 104,319 81 33,380 26 70,939 - 55 - 06-08 148,927 112,517 76 25,702 17 86,815 - 58 - 07-09 111,854 124,259 111 23,266 21 100,993 - 90 - 08-10 91,253 123,431 135 20,391 22 103,040 - 113 - 09-11 91,512 119,528 131 21,984 24 97,543 - 107 - 10-12 95,822 87,057 91 16,506 17 70,551 - 74 - 11-13 97,804 73,442 75 6,580 7 66,862 - 68 - 12-14 108,118 65,724 61 1,710 2 64,014 - 59 - 13-15 215,753 67,143 31 1,017 0 66,127 - 31 - 14-16 642,134 44,718 7 0 44,718 - 7 - 15-17 1,645,174 25,403 2 0 25,403 - 2 - 16-18 1,980,452 608 0 0 608 - 0 17-19 1,811,870 11,411 1 0 11,411 - 1 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-88 Attachment C J. Spanos, Avista Page 448 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNTS 373.10, 373.20, 373.30, 373.40 AND 373.50 STREET LIGHTING AND SIGNAL SYSTEMS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 1,002,768 10,971 1 0 10,971 - 1 - 19-21 714,115 12,552 2 0 12,552 - 2 - FIVE-YEAR AVERAGE 17-21 1,344,120 7,795 1 0 7,795 - 1 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-89 Attachment C J. Spanos, Avista Page 449 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY SUMMARY OF BOOK SALVAGE 1983 2,971 0 0 0 1984 10,275 786 8 0 786 - 8 - 1985 13,317 219 2 100 1 119 - 1 - 1986 5,247 1,578 30 0 1,578 - 30 - 1987 10,217 41 0 0 41 - 0 1988 3,975 142 4 0 142 - 4 - 1989 316 0 0 0 1990 1991 11,026 0 0 0 1992 21,748 21,748 - 1993 4,643 4,643 - 1994 24,156 0 0 0 1995 27,429 0 0 0 1996 1997 1998 1999 2000 98,971 0 0 0 2001 2,497 0 0 0 2002 27,309 0 0 0 2003 29,106 0 0 0 2004 2005 2006 3,038 0 0 0 2007 2008 11,753 0 0 0 2009 1,290 0 0 0 2010 32,336 0 0 0 2011 21,099 0 0 0 2012 387 1,084 280 0 1,084 - 280 - 2013 25,548 0 0 0 2014 15,705 0 0 0 2015 49,559 0 0 0 2016 10,014 421 4 0 421 - 4 - 2017 3,750 0 0 0 2018 113,762 1,588 1 0 1,588 - 1 - 2019 88,896 0 0 0 2020 21,359 0 0 0 2021 96,760 14,035 15 0 14,035 - 15 - TOTAL 762,067 46,286 6 100 0 46,185 - 6 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-90 Attachment C J. Spanos, Avista Page 450 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 8,854 335 4 33 0 302 - 3 - 84-86 9,613 861 9 33 0 828 - 9 - 85-87 9,594 613 6 33 0 579 - 6 - 86-88 6,480 587 9 0 587 - 9 - 87-89 4,836 61 1 0 61 - 1 - 88-90 1,430 47 3 0 47 - 3 - 89-91 3,781 0 0 0 90-92 3,675 7,249 197 0 7,249 - 197 - 91-93 3,675 8,797 239 0 8,797 - 239 - 92-94 8,052 8,797 109 0 8,797 - 109 - 93-95 17,195 1,548 9 0 1,548 - 9 - 94-96 17,195 0 0 0 95-97 9,143 0 0 0 96-98 97-99 98-00 32,990 0 0 0 99-01 33,823 0 0 0 00-02 42,926 0 0 0 01-03 19,638 0 0 0 02-04 18,805 0 0 0 03-05 9,702 0 0 0 04-06 1,013 0 0 0 05-07 1,013 0 0 0 06-08 4,930 0 0 0 07-09 4,348 0 0 0 08-10 15,126 0 0 0 09-11 18,242 0 0 0 10-12 17,940 361 2 0 361 - 2 - 11-13 15,678 361 2 0 361 - 2 - 12-14 13,880 361 3 0 361 - 3 - 13-15 30,270 0 0 0 14-16 25,092 140 1 0 140 - 1 - 15-17 21,107 140 1 0 140 - 1 - 16-18 42,508 670 2 0 670 - 2 - 17-19 68,803 529 1 0 529 - 1 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-91 Attachment C J. Spanos, Avista Page 451 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 74,672 529 1 0 529 - 1 - 19-21 69,005 4,678 7 0 4,678 - 7 - FIVE-YEAR AVERAGE 17-21 64,905 3,125 5 0 3,125 - 5 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-92 Attachment C J. Spanos, Avista Page 452 of 800 GAS PLANT _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-93 Attachment C J. Spanos, Avista Page 453 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 375.00 STRUCTURES AND IMPROVEMENTS SUMMARY OF BOOK SALVAGE 1999 6,228 0 0 0 2000 18,033 0 0 0 2001 1,458 - 0 0 0 2002 1,146 0 0 0 2003 3,963 0 0 0 2004 4,222 694 16 46 1 648 - 15 - 2005 2006 9,892 6,077 - 61 - 0 6,077 61 2007 2,594 1,984 77 0 1,984 - 77 - 2008 420 420 - 2009 2010 2011 64,480 0 0 0 2012 636 0 0 0 2013 21,897 0 0 0 2014 22,428 0 0 0 2015 3,710 0 0 0 2016 4,154 0 0 0 2017 13,775 0 0 0 2018 81,839 0 0 0 2019 3,034 5,583 184 0 5,583 - 184 - 2020 7,265 0 0 0 2021 16,331 0 0 0 TOTAL 284,169 2,604 1 46 0 2,558 - 1 - THREE-YEAR MOVING AVERAGES 99-01 7,601 0 0 0 00-02 5,907 0 0 0 01-03 1,217 0 0 0 02-04 3,110 231 7 15 0 216- 7 - 03-05 2,728 231 8 15 1 216- 8 - 04-06 4,704 1,794 - 38 - 15 0 1,810 38 05-07 4,162 1,364 - 33 - 0 1,364 33 06-08 4,162 1,224 - 29 - 0 1,224 29 07-09 865 801 93 0 801- 93 - 08-10 140 140- 09-11 21,493 0 0 0 10-12 21,705 0 0 0 11-13 29,004 0 0 0 12-14 14,987 0 0 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-94 Attachment C J. Spanos, Avista Page 454 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 375.00 STRUCTURES AND IMPROVEMENTS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 13-15 16,012 0 0 0 14-16 10,097 0 0 0 15-17 7,213 0 0 0 16-18 33,256 0 0 0 17-19 32,883 1,861 6 0 1,861- 6 - 18-20 30,713 1,861 6 0 1,861- 6 - 19-21 8,877 1,861 21 0 1,861- 21 - FIVE-YEAR AVERAGE 17-21 24,449 1,117 5 0 1,117- 5 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-95 Attachment C J. Spanos, Avista Page 455 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 376.00 MAINS SUMMARY OF BOOK SALVAGE 1983 22,213 9,164 41 5,254 24 3,910 - 18 - 1984 3,712 2,383 64 22,140 596 19,757 532 1985 16,998 7,228 43 4,698 28 2,530 - 15 - 1986 43,243 13,585 31 859 - 2 - 14,444 - 33 - 1987 4,214 3,507 83 601 14 2,906 - 69 - 1988 69,993 16,829 24 2,227 3 14,602 - 21 - 1989 44,598 11,866 27 979 2 10,887 - 24 - 1990 29,035 676 2 1,733 6 1,057 4 1991 9,526 3,820 40 218 2 3,602 - 38 - 1992 64,540 16,770 26 102,936 159 86,166 134 1993 50,674 50,124 99 186 0 49,938 - 99 - 1994 20,777 60,001 289 28,235 136 31,766 - 153 - 1995 92,411 100,746 109 1,354 1 99,392 - 108 - 1996 65,109 84,570 130 5,127 8 79,444 - 122 - 1997 159,349 110,935 70 16,506 10 94,429 - 59 - 1998 546,464 91,528 17 13,437 2 78,091 - 14 - 1999 419,581 48,661 12 51,309 12 2,648 1 2000 161,384 113,541 70 6,540 4 107,000 - 66 - 2001 99,410 51,686 52 60,901 61 9,215 9 2002 181,319 41,379 23 4,016 2 37,363 - 21 - 2003 194,539 54,688 28 2,529 1 52,160 - 27 - 2004 163,695 38,665 24 723 0 37,942 - 23 - 2005 187,536 51,601 28 0 51,601 - 28 - 2006 881,956 125,862 14 179 0 125,682 - 14 - 2007 576,120 178,583 31 0 178,583 - 31 - 2008 791,997 256,750 32 24,972 3 231,778 - 29 - 2009 469,915 223,918 48 4,767 1 219,151 - 47 - 2010 512,040 202,023 39 2,396 0 199,627 - 39 - 2011 466,550 152,425 33 508 0 151,917 - 33 - 2012 594,414 126,287 21 0 126,287 - 21 - 2013 2,750,709 190,426 7 0 190,426 - 7 - 2014 1,969,013 497,590 25 0 497,590 - 25 - 2015 1,390,887 314,912 23 0 314,912 - 23 - 2016 1,665,978 478,274 29 0 478,274 - 29 - 2017 1,018,837 24 0 0 24 - 0 2018 706,348 45,514 6 0 45,514 - 6 - 2019 6,719,231 7,168 0 0 7,168 - 0 2020 1,092,350 3,474 0 0 3,474 - 0 2021 690,918 0 0 0 TOTAL 24,947,580 3,787,183 15 363,612 1 3,423,571 - 14 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-96 Attachment C J. Spanos, Avista Page 456 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 376.00 MAINS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 14,308 6,258 44 10,697 75 4,439 31 84-86 21,318 7,732 36 8,660 41 928 4 85-87 21,485 8,107 38 1,480 7 6,627 - 31 - 86-88 39,150 11,307 29 656 2 10,651 - 27 - 87-89 39,602 10,734 27 1,269 3 9,465 - 24 - 88-90 47,875 9,790 20 1,646 3 8,144 - 17 - 89-91 27,720 5,454 20 977 4 4,477 - 16 - 90-92 34,367 7,089 21 34,962 102 27,874 81 91-93 41,580 23,571 57 34,447 83 10,875 26 92-94 45,330 42,298 93 43,786 97 1,487 3 93-95 54,621 70,290 129 9,925 18 60,365 - 111 - 94-96 59,432 81,772 138 11,572 19 70,201 - 118 - 95-97 105,623 98,750 93 7,662 7 91,088 - 86 - 96-98 256,974 95,678 37 11,690 5 83,988 - 33 - 97-99 375,132 83,708 22 27,084 7 56,624 - 15 - 98-00 375,810 84,577 23 23,762 6 60,814 - 16 - 99-01 226,792 71,296 31 39,583 17 31,713 - 14 - 00-02 147,371 68,869 47 23,819 16 45,050 - 31 - 01-03 158,422 49,251 31 22,482 14 26,769 - 17 - 02-04 179,851 44,911 25 2,423 1 42,488 - 24 - 03-05 181,923 48,318 27 1,084 1 47,234 - 26 - 04-06 411,062 72,042 18 301 0 71,742 - 17 - 05-07 548,537 118,682 22 60 0 118,622 - 22 - 06-08 750,024 187,065 25 8,384 1 178,681 - 24 - 07-09 612,677 219,750 36 9,913 2 209,837 - 34 - 08-10 591,317 227,564 38 10,711 2 216,852 - 37 - 09-11 482,835 192,789 40 2,557 1 190,232 - 39 - 10-12 524,334 160,245 31 968 0 159,277 - 30 - 11-13 1,270,557 156,379 12 169 0 156,210 - 12 - 12-14 1,771,378 271,434 15 0 271,434 - 15 - 13-15 2,036,870 334,309 16 0 334,309 - 16 - 14-16 1,675,292 430,259 26 0 430,259 - 26 - 15-17 1,358,567 264,404 19 0 264,404 - 19 - 16-18 1,130,387 174,604 15 0 174,604 - 15 - 17-19 2,814,805 17,569 1 0 17,569 - 1 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-97 Attachment C J. Spanos, Avista Page 457 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 376.00 MAINS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 2,839,310 18,719 1 0 18,719 - 1 - 19-21 2,834,166 3,547 0 0 3,547 - 0 FIVE-YEAR AVERAGE 17-21 2,045,537 11,236 1 0 11,236 - 1 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-98 Attachment C J. Spanos, Avista Page 458 of 800 AVISTA CORPORATION GAS PLANT ACCOUNTS 378.00, 379.00 AND 385.00 MEASURING AND REGULATING EQUIPMENT SUMMARY OF BOOK SALVAGE 1983 9,292 1,342 14 1,167 13 175 - 2 - 1984 2,121 0 0 0 1985 579 0 636 110 636 110 1986 1,618 575 36 995 61 420 26 1987 442 0 0 0 1988 1989 1,922 512 27 0 512 - 27 - 1990 34,306 276 1 0 276 - 1 - 1991 1992 1,455 1,303 90 0 1,303 - 90 - 1993 1994 3,404 9,832 289 0 9,832 - 289 - 1995 9,961 7,590 76 0 7,590 - 76 - 1996 2,739 2,845 104 202 7 2,643 - 96 - 1997 21,883 1,706 8 0 1,706 - 8 - 1998 115,442 9,214 8 0 9,214 - 8 - 1999 33,832 5,775 17 0 5,775 - 17 - 2000 174,989 2,615 1 0 2,615 - 1 - 2001 129,262 2,972 2 0 2,972 - 2 - 2002 25,620 2,307 9 5 0 2,302 - 9 - 2003 42,200 4,767 11 84 0 4,683 - 11 - 2004 34,200 5,611 16 621 2 4,990 - 15 - 2005 24,210 0 0 0 2006 35,710 9,926 28 0 9,926 - 28 - 2007 60,356 6,939 11 0 6,939 - 11 - 2008 66,025 8,978 14 0 8,978 - 14 - 2009 34,417 4,388 13 0 4,388 - 13 - 2010 308,685 38,072 12 0 38,072 - 12 - 2011 193,602 33,445 17 0 33,445 - 17 - 2012 74,151 2,727 4 0 2,727 - 4 - 2013 147,567 870 1 0 870 - 1 - 2014 145,702 7,693 5 0 7,693 - 5 - 2015 82,307 17,687 21 0 17,687 - 21 - 2016 51,786 84,066 162 0 84,066 - 162 - 2017 231,344 862 0 0 862 - 0 2018 957,638 50,403 5 21,221 2 29,182 - 3 - 2019 120,094 8,572 7 15,495 13 6,923 6 2020 56,203 20,454 36 0 20,454 - 36 - 2021 53,683 1,959 4 0 1,959 - 4 - TOTAL 3,288,746 356,280 11 40,426 1 315,854 - 10 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-99 Attachment C J. Spanos, Avista Page 459 of 800 AVISTA CORPORATION GAS PLANT ACCOUNTS 378.00, 379.00 AND 385.00 MEASURING AND REGULATING EQUIPMENT SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 3,997 447 11 601 15 154 4 84-86 1,439 192 13 544 38 352 24 85-87 880 192 22 544 62 352 40 86-88 687 192 28 332 48 140 20 87-89 788 171 22 0 171 - 22 - 88-90 12,076 263 2 0 263 - 2 - 89-91 12,076 263 2 0 263 - 2 - 90-92 11,920 526 4 0 526 - 4 - 91-93 485 434 90 0 434 - 90 - 92-94 1,620 3,712 229 0 3,712 - 229 - 93-95 4,455 5,807 130 0 5,807 - 130 - 94-96 5,368 6,756 126 67 1 6,688 - 125 - 95-97 11,527 4,047 35 67 1 3,979 - 35 - 96-98 46,688 4,588 10 67 0 4,521 - 10 - 97-99 57,052 5,565 10 0 5,565 - 10 - 98-00 108,088 5,868 5 0 5,868 - 5 - 99-01 112,694 3,787 3 0 3,787 - 3 - 00-02 109,957 2,631 2 2 0 2,629 - 2 - 01-03 65,694 3,348 5 30 0 3,319 - 5 - 02-04 34,007 4,228 12 237 1 3,991 - 12 - 03-05 33,537 3,459 10 235 1 3,224 - 10 - 04-06 31,373 5,179 17 207 1 4,972 - 16 - 05-07 40,092 5,622 14 0 5,622 - 14 - 06-08 54,030 8,614 16 0 8,614 - 16 - 07-09 53,599 6,768 13 0 6,768 - 13 - 08-10 136,376 17,146 13 0 17,146 - 13 - 09-11 178,901 25,301 14 0 25,301 - 14 - 10-12 192,146 24,748 13 0 24,748 - 13 - 11-13 138,440 12,347 9 0 12,347 - 9 - 12-14 122,473 3,764 3 0 3,764 - 3 - 13-15 125,192 8,750 7 0 8,750 - 7 - 14-16 93,265 36,482 39 0 36,482 - 39 - 15-17 121,813 34,205 28 0 34,205 - 28 - 16-18 413,590 45,110 11 7,074 2 38,037 - 9 - 17-19 436,359 19,945 5 12,239 3 7,707 - 2 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-100 Attachment C J. Spanos, Avista Page 460 of 800 AVISTA CORPORATION GAS PLANT ACCOUNTS 378.00, 379.00 AND 385.00 MEASURING AND REGULATING EQUIPMENT SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 377,978 26,476 7 12,239 3 14,238 - 4 - 19-21 76,660 10,328 13 5,165 7 5,163 - 7 - FIVE-YEAR AVERAGE 17-21 283,793 16,450 6 7,343 3 9,107 - 3 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-101 Attachment C J. Spanos, Avista Page 461 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 380.00 SERVICES SUMMARY OF BOOK SALVAGE 1983 63,547 26,221 41 2,829 4 23,392- 37 - 1984 41,025 26,329 64 654 2 25,675- 63 - 1985 44,682 19,001 43 841 2 18,160- 41 - 1986 52,137 16,854 32 575 1 16,279- 31 - 1987 26,011 25,215 97 4,820 19 20,395- 78 - 1988 48,155 11,506 24 101 0 11,405- 24 - 1989 55,875 14,866 27 314 1 14,552- 26 - 1990 360,279 20,627 6 0 20,627- 6 - 1991 23,558 9,533 40 275 - 1 - 9,808- 42 - 1992 91,294 23,722 26 783 1 22,939- 25 - 1993 49,957 0 718 1 718 1 1994 77,927 0 0 0 1995 89,378 62,164 70 5,326 6 56,838- 64 - 1996 98,677 42,177 43 7,267 7 34,910- 35 - 1997 157,715 60,783 39 3,237 2 57,546- 36 - 1998 563,462 56,355 10 3,104 1 53,251- 9 - 1999 321,828 82,948 26 5,092 2 77,856- 24 - 2000 334,216 68,484 20 1,359 0 67,124- 20 - 2001 238,166 61,749 26 12,657 5 49,091- 21 - 2002 375,026 48,197 13 926 0 47,271- 13 - 2003 237,926 93,187 39 1,970 1 91,218- 38 - 2004 407,880 99,900 24 1,780 0 98,120- 24 - 2005 1,059,454 81,462 8 0 81,462- 8 - 2006 1,363,689 105,724 8 3 0 105,721- 8 - 2007 371,772 57,908 16 0 57,908- 16 - 2008 473,537 222,979 47 6,736 1 216,243- 46 - 2009 634,002 113,051 18 5,879 1 107,172- 17 - 2010 591,714 210,354 36 14,856 3 195,498- 33 - 2011 423,057 262,632 62 10,167 2 252,465- 60 - 2012 343,250 95,414 28 0 95,414- 28 - 2013 242,218 30,027 12 0 30,027- 12 - 2014 629,163 143,840 23 0 143,840- 23 - 2015 456,588 211,502 46 11 0 211,491- 46 - 2016 348,901 232,869 67 0 232,869- 67 - 2017 442,561 95 0 0 95- 0 2018 308,810 8,135 3 1,012 0 7,122- 2 - 2019 553,346 820 0 0 820- 0 2020 339,933 0 0 0 2021 236,967 0 0 0 TOTAL 12,577,684 2,646,628 21 92,743 1 2,553,885- 20 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-102 Attachment C J. Spanos, Avista Page 462 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 380.00 SERVICES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 49,751 23,850 48 1,441 3 22,409- 45 - 84-86 45,948 20,728 45 690 2 20,038- 44 - 85-87 40,943 20,357 50 2,079 5 18,278- 45 - 86-88 42,101 17,858 42 1,832 4 16,026- 38 - 87-89 43,347 17,196 40 1,745 4 15,451- 36 - 88-90 154,770 15,666 10 138 0 15,528- 10 - 89-91 146,571 15,009 10 13 0 14,996- 10 - 90-92 158,377 17,961 11 169 0 17,791- 11 - 91-93 54,936 11,085 20 409 1 10,676- 19 - 92-94 73,059 7,907 11 500 1 7,407- 10 - 93-95 72,421 20,721 29 2,015 3 18,707- 26 - 94-96 88,661 34,780 39 4,198 5 30,583- 34 - 95-97 115,257 55,041 48 5,277 5 49,765- 43 - 96-98 273,285 53,105 19 4,536 2 48,569- 18 - 97-99 347,668 66,695 19 3,811 1 62,884- 18 - 98-00 406,502 69,262 17 3,185 1 66,077- 16 - 99-01 298,070 71,060 24 6,370 2 64,690- 22 - 00-02 315,803 59,476 19 4,981 2 54,495- 17 - 01-03 283,706 67,711 24 5,185 2 62,527- 22 - 02-04 340,277 80,428 24 1,559 0 78,869- 23 - 03-05 568,420 91,516 16 1,250 0 90,266- 16 - 04-06 943,674 95,695 10 594 0 95,101- 10 - 05-07 931,638 81,698 9 1 0 81,697- 9 - 06-08 736,333 128,870 18 2,246 0 126,624- 17 - 07-09 493,104 131,313 27 4,205 1 127,108- 26 - 08-10 566,418 182,128 32 9,157 2 172,971- 31 - 09-11 549,591 195,345 36 10,300 2 185,045- 34 - 10-12 452,674 189,466 42 8,341 2 181,125- 40 - 11-13 336,175 129,357 38 3,389 1 125,968- 37 - 12-14 404,877 89,760 22 0 89,760- 22 - 13-15 442,657 128,456 29 4 0 128,452- 29 - 14-16 478,218 196,070 41 4 0 196,067- 41 - 15-17 416,017 148,155 36 4 0 148,152- 36 - 16-18 366,758 80,366 22 338 0 80,029- 22 - 17-19 434,906 3,017 1 338 0 2,679- 1 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-103 Attachment C J. Spanos, Avista Page 463 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 380.00 SERVICES SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 400,696 2,985 1 338 0 2,647- 1 - 19-21 376,748 273 0 0 273- 0 FIVE-YEAR AVERAGE 17-21 376,323 1,810 0 202 0 1,607- 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-104 Attachment C J. Spanos, Avista Page 464 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 381.00 METERS SUMMARY OF BOOK SALVAGE 1983 1,824 753 41 1,845 101 1,092 60 1984 1,825 1,167 64 610 33 557 - 31 - 1985 3,434 1,460 43 405 12 1,055 - 31 - 1986 2,193 688 31 3,420 156 2,732 125 1987 5,046 4,208 83 721 14 3,487 - 69 - 1988 89 89 - 1989 2,810 748 27 0 748 - 27 - 1990 2,736 64 2 1,360 50 1,296 47 1991 27,185 10,904 40 7,838 29 3,066 - 11 - 1992 29,481 7,661 26 2,485 8 5,176 - 18 - 1993 28,853 0 1,191 4 1,191 4 1994 29,654 0 0 0 1995 240,023 0 210 0 210 0 1996 323,524 0 0 0 1997 133,292 0 751 1 751 1 1998 130,569 0 648 0 648 0 1999 217,117 0 1,571 1 1,571 1 2000 454,431 48,309 11 297 0 48,012 - 11 - 2001 429,390 51,384 12 2,765 1 48,619 - 11 - 2002 345,550 39,947 12 271 0 39,677 - 11 - 2003 353,759 81,145 23 1,503 0 79,642 - 23 - 2004 346,384 78,098 23 2,391 1 75,707 - 22 - 2005 706,741 14,269 - 2 - 0 14,269 2 2006 483,767 14,006 - 3 - 0 14,006 3 2007 748,113 6,572 - 1 - 21,109 3 27,681 4 2008 741,128 45,193 6 9,525 1 35,669 - 5 - 2009 3,499,708 75,454 2 2,411 0 73,044 - 2 - 2010 2,638,818 5,333 0 11,184 0 5,851 0 2011 2,473,317 24,536 - 1 - 2,443 0 26,979 1 2012 2,356,540 4,099 - 0 0 4,099 0 2013 1,900,644 9,363 - 0 0 9,363 0 2014 1,551,381 3,077 0 0 3,077 - 0 2015 166,372 6,706 4 1 0 6,705 - 4 - 2016 1,466,842 14,531 1 0 14,531 - 1 - 2017 2,576,930 0 1 0 1 0 2018 2,767,972 0 0 0 2019 5,113,418 281,388 6 0 281,388 - 6 - 2020 4,639,825 263,570 6 0 263,570 - 6 - 2021 3,684,638 143,210 4 0 143,210 - 4 - TOTAL 40,625,232 1,092,243 3 76,956 0 1,015,287 - 2 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-105 Attachment C J. Spanos, Avista Page 465 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 381.00 METERS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 83-85 2,361 1,127 48 953 40 173- 7 - 84-86 2,484 1,105 44 1,478 60 373 15 85-87 3,558 2,119 60 1,515 43 603- 17 - 86-88 2,413 1,662 69 1,380 57 281- 12 - 87-89 2,619 1,682 64 240 9 1,441- 55 - 88-90 1,849 300 16 453 25 153 8 89-91 10,910 3,905 36 3,066 28 839- 8 - 90-92 19,801 6,210 31 3,894 20 2,315- 12 - 91-93 28,506 6,188 22 3,838 13 2,350- 8 - 92-94 29,329 2,554 9 1,225 4 1,328- 5 - 93-95 99,510 0 467 0 467 0 94-96 197,734 0 70 0 70 0 95-97 232,280 0 320 0 320 0 96-98 195,795 0 466 0 466 0 97-99 160,326 0 990 1 990 1 98-00 267,372 16,103 6 839 0 15,264- 6 - 99-01 366,979 33,231 9 1,544 0 31,687- 9 - 00-02 409,790 46,547 11 1,111 0 45,436- 11 - 01-03 376,233 57,492 15 1,513 0 55,979- 15 - 02-04 348,564 66,397 19 1,388 0 65,008- 19 - 03-05 468,961 48,325 10 1,298 0 47,027- 10 - 04-06 512,297 16,608 3 797 0 15,810- 3 - 05-07 646,207 11,616 - 2 - 7,036 1 18,652 3 06-08 657,669 8,205 1 10,211 2 2,006 0 07-09 1,662,983 38,025 2 11,015 1 27,010- 2 - 08-10 2,293,218 41,994 2 7,707 0 34,287- 1 - 09-11 2,870,614 18,750 1 5,346 0 13,404- 0 10-12 2,489,558 7,767 - 0 4,542 0 12,310 0 11-13 2,243,500 12,666 - 1 - 814 0 13,480 1 12-14 1,936,189 3,462 - 0 0 3,462 0 13-15 1,206,132 140 0 0 140- 0 14-16 1,061,532 8,105 1 0 8,105- 1 - 15-17 1,403,381 7,079 1 1 0 7,079- 1 - 16-18 2,270,582 4,844 0 0 4,843- 0 17-19 3,486,107 93,796 3 0 93,796- 3 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-106 Attachment C J. Spanos, Avista Page 466 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 381.00 METERS SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 18-20 4,173,738 181,652 4 0 181,652- 4 - 19-21 4,479,294 229,389 5 0 229,389- 5 - FIVE-YEAR AVERAGE 17-21 3,756,557 137,634 4 0 137,633- 4 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-107 Attachment C J. Spanos, Avista Page 467 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY SUMMARY OF BOOK SALVAGE 1999 380 0 0 0 2000 65,284 0 0 0 2001 15,999 0 0 0 2002 331 331 2003 11,275 0 0 0 2004 1,951 0 0 0 2005 2006 7,820 180 - 2 - 0 180 2 2007 111,393 0 0 0 2008 30,499 0 0 0 2009 7,893 0 0 0 2010 404,868 0 348,307 86 348,307 86 2011 212,501 212,501- 2012 15,391 3,526 23 0 3,526- 23 - 2013 1,812 0 0 0 2014 36,476 0 0 0 2015 2016 3,994 52 1 0 52- 1 - 2017 2018 23,944 0 0 0 2019 2020 54,633 0 0 0 2021 579,176 0 0 0 TOTAL 1,372,791 215,898 16 348,638 25 132,740 10 THREE-YEAR MOVING AVERAGES 99-01 27,221 0 0 0 00-02 27,095 0 110 0 110 0 01-03 9,092 0 110 1 110 1 02-04 4,409 0 110 3 110 3 03-05 4,409 0 0 0 04-06 3,257 60 - 2 - 0 60 2 05-07 39,738 60 - 0 0 60 0 06-08 49,904 60 - 0 0 60 0 07-09 49,928 0 0 0 08-10 147,753 0 116,102 79 116,102 79 09-11 137,587 70,834 51 116,102 84 45,269 33 10-12 140,086 72,009 51 116,102 83 44,093 31 11-13 5,734 72,009 0 72,009- 12-14 17,893 1,175 7 0 1,175- 7 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-108 Attachment C J. Spanos, Avista Page 468 of 800 AVISTA CORPORATION GAS PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY SUMMARY OF BOOK SALVAGE THREE-YEAR MOVING AVERAGES 13-15 12,763 0 0 0 14-16 13,490 17 0 0 17- 0 15-17 1,332 17 1 0 17- 1 - 16-18 9,313 17 0 0 17- 0 17-19 7,982 0 0 0 18-20 26,192 0 0 0 19-21 211,270 0 0 0 FIVE-YEAR AVERAGE 17-21 131,551 0 0 0 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-109 Attachment C J. Spanos, Avista Page 469 of 800 COMMON PLANT _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-110 Attachment C J. Spanos, Avista Page 470 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY SUMMARY OF BOOK SALVAGE 2005 28,086 0 0 0 2006 79,256 0 0 0 2007 166,430 1,332 1 0 1,332 - 1 - 2008 3,024,260 8,446 0 0 8,446 - 0 2009 23,580 14,411 61 6,500 28 7,911 - 34 - 2010 85,815 10,042 12 5,603 7 4,439 - 5 - 2011 24,865 11,159 45 620 2 10,539 - 42 - 2012 814,237 10,656 - 1 - 0 10,656 1 2013 1,755,703 4,703 0 0 4,703 - 0 2014 5,631,971 30,435 1 0 30,435 - 1 - 2015 1,025,250 195,641 19 0 195,641 - 19 - 2016 123,062 126,202 103 0 126,202 - 103 - 2017 727,775 16,285 2 0 16,285 - 2 - 2018 3,928,154 93,720 2 0 93,720 - 2 - 2019 1,566,539 461,622 29 0 461,622 - 29 - 2020 235,620 41,447 18 1,000 0 40,447 - 17 - 2021 469,740 76,731 16 0 76,731 - 16 - TOTAL 19,710,342 1,081,521 5 13,724 0 1,067,797 - 5 - THREE-YEAR MOVING AVERAGES 05-07 91,257 444 0 0 444- 0 06-08 1,089,982 3,259 0 0 3,259- 0 07-09 1,071,423 8,063 1 2,167 0 5,896- 1 - 08-10 1,044,552 10,966 1 4,034 0 6,932- 1 - 09-11 44,753 11,871 27 4,241 9 7,630- 17 - 10-12 308,305 3,515 1 2,075 1 1,440- 0 11-13 864,935 1,735 0 207 0 1,529- 0 12-14 2,733,970 8,161 0 0 8,161- 0 13-15 2,804,308 76,927 3 0 76,927- 3 - 14-16 2,260,094 117,426 5 0 117,426- 5 - 15-17 625,362 112,709 18 0 112,709- 18 - 16-18 1,592,997 78,736 5 0 78,736- 5 - 17-19 2,074,156 190,542 9 0 190,542- 9 - 18-20 1,910,105 198,930 10 333 0 198,596- 10 - 19-21 757,300 193,267 26 333 0 192,933- 25 - FIVE-YEAR AVERAGE 17-21 1,385,566 137,961 10 200 0 137,761- 10 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-111 Attachment C J. Spanos, Avista Page 471 of 800 ELECTRIC, GAS AND COMMON PLANT _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-112 Attachment C J. Spanos, Avista Page 472 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 392.10 TRANSPORTATION EQUIPMENT - AUTOS SUMMARY OF BOOK SALVAGE 2010 18,206 0 3,165 17 3,165 17 2011 151,610 0 8,788 6 8,788 6 2012 2013 2014 2015 2016 2017 2018 99,414 0 0 0 2019 2020 39,870 0 37,976 95 37,976 95 2021 TOTAL 309,100 0 49,929 16 49,929 16 THREE-YEAR MOVING AVERAGES 10-12 56,605 0 3,984 7 3,984 7 11-13 50,537 0 2,929 6 2,929 6 12-14 13-15 14-16 15-17 16-18 33,138 0 0 0 17-19 33,138 0 0 0 18-20 46,428 0 12,659 27 12,659 27 19-21 13,290 0 12,659 95 12,659 95 FIVE-YEAR AVERAGE 17-21 27,857 0 7,595 27 7,595 27 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-113 Attachment C J. Spanos, Avista Page 473 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 392.20 TRANSPORTATION EQUIPMENT - LIGHT TRUCKS SUMMARY OF BOOK SALVAGE 2005 20,795 20,795 2006 99,753 0 73,057 73 73,057 73 2007 609,838 0 37,379 6 37,379 6 2008 132,241 0 27,160 21 27,160 21 2009 366,736 0 26,847 7 26,847 7 2010 316,866 201 0 60,129 19 59,928 19 2011 616,486 0 67,076 11 67,076 11 2012 522,297 8,861 - 2 - 0 8,861 2 2013 288,412 13,956 - 5 - 148,918 52 162,874 56 2014 405,035 0 128,415 32 128,415 32 2015 1,291,460 0 161,654 13 161,654 13 2016 637,975 0 332,866 52 332,866 52 2017 765,318 0 231,477 30 231,477 30 2018 1,457,118 0 440,718 30 440,718 30 2019 890,745 0 269,414 30 269,414 30 2020 486,836 0 147,248 30 147,248 30 2021 992,123 0 0 0 TOTAL 9,879,239 22,616 - 0 2,173,153 22 2,195,770 22 THREE-YEAR MOVING AVERAGES 05-07 236,530 0 43,744 18 43,744 18 06-08 280,611 0 45,865 16 45,865 16 07-09 369,605 0 30,462 8 30,462 8 08-10 271,948 67 0 38,045 14 37,978 14 09-11 433,363 67 0 51,351 12 51,284 12 10-12 485,216 2,887 - 1 - 42,402 9 45,288 9 11-13 475,732 7,606 - 2 - 71,998 15 79,604 17 12-14 405,248 7,606 - 2 - 92,444 23 100,050 25 13-15 661,635 4,652 - 1 - 146,329 22 150,981 23 14-16 778,156 0 207,645 27 207,645 27 15-17 898,251 0 241,999 27 241,999 27 16-18 953,470 0 335,021 35 335,021 35 17-19 1,037,727 0 313,870 30 313,870 30 18-20 944,900 0 285,793 30 285,793 30 19-21 789,901 0 138,887 18 138,887 18 FIVE-YEAR AVERAGE 17-21 918,428 0 217,772 24 217,772 24 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-114 Attachment C J. Spanos, Avista Page 474 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 392.30 TRANSPORTATION EQUIPMENT - MEDIUM TRUCKS SUMMARY OF BOOK SALVAGE 2005 8,912 8,912 2006 16,023 6,421- 40 - 35,378 221 41,799 261 2007 280,833 0 23,396 8 23,396 8 2008 215,582 0 34,541 16 34,541 16 2009 204,261 0 18,268 9 18,268 9 2010 533,708 0 105,490 20 105,490 20 2011 338,334 0 26,594 8 26,594 8 2012 455,780 498,491- 109 - 0 498,491 109 2013 213,812 3,059- 1 - 132,371 62 135,431 63 2014 489,515 0 114,146 23 114,146 23 2015 438,471 0 143,692 33 143,692 33 2016 1,112,276 0 295,881 27 295,881 27 2017 293,354 0 73,969 25 73,969 25 2018 1,421,995 0 358,556 25 358,556 25 2019 797,732 0 201,148 25 201,148 25 2020 741,207 0 186,895 25 186,895 25 2021 931,626 0 0 0 TOTAL 8,484,513 507,972- 6 - 1,759,239 21 2,267,211 27 THREE-YEAR MOVING AVERAGES 05-07 98,952 2,140 - 2 - 22,562 23 24,702 25 06-08 170,813 2,140 - 1 - 31,105 18 33,245 19 07-09 233,559 0 25,402 11 25,402 11 08-10 317,850 0 52,766 17 52,766 17 09-11 358,768 0 50,117 14 50,117 14 10-12 442,608 166,164 - 38 - 44,028 10 210,192 47 11-13 335,976 167,184 - 50 - 52,988 16 220,172 66 12-14 386,369 167,184 - 43 - 82,173 21 249,356 65 13-15 380,600 1,020 - 0 130,070 34 131,090 34 14-16 680,088 0 184,573 27 184,573 27 15-17 614,701 0 171,181 28 171,181 28 16-18 942,542 0 242,802 26 242,802 26 17-19 837,694 0 211,225 25 211,225 25 18-20 986,978 0 248,867 25 248,867 25 19-21 823,522 0 129,348 16 129,348 16 FIVE-YEAR AVERAGE 17-21 837,183 0 164,114 20 164,114 20 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-115 Attachment C J. Spanos, Avista Page 475 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 392.40 TRANSPORTATION EQUIPMENT - HEAVY TRUCKS SUMMARY OF BOOK SALVAGE 2007 74,002 0 0 0 2008 2009 2010 44,618 0 0 0 2011 42,700 42,700 2012 64,802 0 0 0 2013 2014 2015 29,740 0 0 0 2016 2017 2018 103,273 0 131,502 127 131,502 127 2019 2020 2021 TOTAL 316,435 0 174,202 55 174,202 55 THREE-YEAR MOVING AVERAGES 07-09 24,667 0 0 0 08-10 14,873 0 0 0 09-11 14,873 0 14,233 96 14,233 96 10-12 36,473 0 14,233 39 14,233 39 11-13 21,601 0 14,233 66 14,233 66 12-14 21,601 0 0 0 13-15 9,913 0 0 0 14-16 9,913 0 0 0 15-17 9,913 0 0 0 16-18 34,424 0 43,834 127 43,834 127 17-19 34,424 0 43,834 127 43,834 127 18-20 34,424 0 43,834 127 43,834 127 19-21 FIVE-YEAR AVERAGE 17-21 20,655 0 26,300 127 26,300 127 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-116 Attachment C J. Spanos, Avista Page 476 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 392.50 TRANSPORTATION EQUIPMENT - OTHER SUMMARY OF BOOK SALVAGE 2007 63,703 0 113,444 178 113,444 178 2008 166,562 960 1 45,266 27 44,306 27 2009 49,774 0 44,745 90 44,745 90 2010 45,702 0 42,195 92 42,195 92 2011 204,364 0 59,099 29 59,099 29 2012 263,867 1,466 - 1 - 255,816 97 257,282 98 2013 160,558 109 - 0 49,639 31 49,748 31 2014 132,950 0 42,805 32 42,805 32 2015 70,472 0 53,885 76 53,885 76 2016 73,705 0 110,955 151 110,955 151 2017 203,094 0 157,108 77 157,108 77 2018 303,448 0 234,739 77 234,739 77 2019 32,971 0 25,505 77 25,505 77 2020 96,523 0 74,668 77 74,668 77 2021 326,029 0 0 0 TOTAL 2,193,720 615 - 0 1,309,868 60 1,310,484 60 THREE-YEAR MOVING AVERAGES 07-09 93,346 320 0 67,818 73 67,498 72 08-10 87,346 320 0 44,068 50 43,748 50 09-11 99,947 0 48,680 49 48,680 49 10-12 171,311 489 - 0 119,037 69 119,525 70 11-13 209,596 525 - 0 121,518 58 122,043 58 12-14 185,791 525 - 0 116,087 62 116,612 63 13-15 121,326 36 - 0 48,776 40 48,813 40 14-16 92,375 0 69,215 75 69,215 75 15-17 115,757 0 107,316 93 107,316 93 16-18 193,416 0 167,601 87 167,601 87 17-19 179,838 0 139,117 77 139,117 77 18-20 144,314 0 111,637 77 111,637 77 19-21 151,841 0 33,391 22 33,391 22 FIVE-YEAR AVERAGE 17-21 192,413 0 98,404 51 98,404 51 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-117 Attachment C J. Spanos, Avista Page 477 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 396.30 POWER OPERATED EQUIPMENT - MEDIUM TRUCKS SUMMARY OF BOOK SALVAGE 2007 144,702 0 0 0 2008 282,405 0 0 0 2009 222,780 0 0 0 2010 992,096 0 0 0 2011 115,059 0 0 0 2012 1,038,903 34,146 - 3 - 0 34,146 3 2013 2014 2015 2016 2017 145,306 0 98,589 68 98,589 68 2018 2019 354,855 0 240,766 68 240,766 68 2020 477,073 0 323,691 68 323,691 68 2021 783,800 0 0 0 TOTAL 4,556,979 34,146 - 1 - 663,046 15 697,192 15 THREE-YEAR MOVING AVERAGES 07-09 216,629 0 0 0 08-10 499,094 0 0 0 09-11 443,312 0 0 0 10-12 715,353 11,382 - 2 - 0 11,382 2 11-13 384,654 11,382 - 3 - 0 11,382 3 12-14 346,301 11,382 - 3 - 0 11,382 3 13-15 14-16 15-17 48,435 0 32,863 68 32,863 68 16-18 48,435 0 32,863 68 32,863 68 17-19 166,720 0 113,119 68 113,119 68 18-20 277,309 0 188,152 68 188,152 68 19-21 538,576 0 188,152 35 188,152 35 FIVE-YEAR AVERAGE 17-21 352,207 0 132,609 38 132,609 38 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-118 Attachment C J. Spanos, Avista Page 478 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 396.40 POWER OPERATED EQUIPMENT - HEAVY TRUCKS SUMMARY OF BOOK SALVAGE 2007 303,616 0 15,120 5 15,120 5 2008 702,313 0 0 0 2009 171,497 0 8,920 5 8,920 5 2010 1,250,480 942 0 9,680 1 8,738 1 2011 771,024 0 0 0 2012 1,538,222 9,127 - 1 - 0 9,127 1 2013 2014 2015 2016 2017 568,533 0 147,097 26 147,097 26 2018 295,785 0 0 0 2019 76,529 76,529 2020 472,809 0 122,330 26 122,330 26 2021 TOTAL 6,074,279 8,186 - 0 379,677 6 387,862 6 THREE-YEAR MOVING AVERAGES 07-09 392,475 0 8,013 2 8,013 2 08-10 708,097 314 0 6,200 1 5,886 1 09-11 731,000 314 0 6,200 1 5,886 1 10-12 1,186,575 2,729 - 0 3,227 0 5,955 1 11-13 769,749 3,042 - 0 0 3,042 0 12-14 512,741 3,042 - 1 - 0 3,042 1 13-15 14-16 15-17 189,511 0 49,032 26 49,032 26 16-18 288,106 0 49,032 17 49,032 17 17-19 288,106 0 74,542 26 74,542 26 18-20 256,198 0 66,286 26 66,286 26 19-21 157,603 0 66,286 42 66,286 42 FIVE-YEAR AVERAGE 17-21 267,425 0 69,191 26 69,191 26 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-119 Attachment C J. Spanos, Avista Page 479 of 800 AVISTA CORPORATION ELECTRIC, GAS AND COMMON PLANT ACCOUNT 396.50 POWER OPERATED EQUIPMENT - OTHER SUMMARY OF BOOK SALVAGE 2006 55,893 1,211 2 0 1,211 - 2 - 2007 237,453 0 15,170 6 15,170 6 2008 191,103 0 1 0 1 0 2009 465,646 0 0 0 2010 989,807 0 31,500 3 31,500 3 2011 1,210,405 0 0 0 2012 2013 2014 2015 2016 2017 55,714 0 94,789 170 94,789 170 2018 88,136 0 149,951 170 149,951 170 2019 355,369 0 604,609 170 604,609 170 2020 29,896 0 50,863 170 50,863 170 2021 94,759 0 0 0 TOTAL 3,774,181 1,211 0 946,883 25 945,672 25 THREE-YEAR MOVING AVERAGES 06-08 161,483 404 0 5,057 3 4,653 3 07-09 298,067 0 5,057 2 5,057 2 08-10 548,852 0 10,500 2 10,500 2 09-11 888,619 0 10,500 1 10,500 1 10-12 733,404 0 10,500 1 10,500 1 11-13 403,468 0 0 0 12-14 13-15 14-16 15-17 18,571 0 31,596 170 31,596 170 16-18 47,950 0 81,580 170 81,580 170 17-19 166,406 0 283,116 170 283,116 170 18-20 157,801 0 268,474 170 268,474 170 19-21 160,008 0 218,491 137 218,491 137 FIVE-YEAR AVERAGE 17-21 124,775 0 180,042 144 180,042 144 _____________________________________________________________________________________________ Avista Corporation December 31, 2021VIII-120 Attachment C J. Spanos, Avista Page 480 of 800 PART IX. DETAILED DEPRECIATION CALCULATIONS _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-1 Attachment C J. Spanos, Avista Page 481 of 800 ELECTRIC PLANT _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-2 Attachment C J. Spanos, Avista Page 482 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 310.30 REMOVING OTHER PROPERTY CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 KETTLE FALLS INTERIM SURVIVOR CURVE.. SQUARE PROBABLE RETIREMENT YEAR.. 12-2038 NET SALVAGE PERCENT.. 0 1983 138,174.50 95,850 125,750 12,424 17.00 731 138,174.50 95,850 125,750 12,424 731 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 17.0 0.53 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-3 Attachment C J. Spanos, Avista Page 483 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 310.40 EASEMENTS, PERMITS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 KETTLE FALLS INTERIM SURVIVOR CURVE.. SQUARE PROBABLE RETIREMENT YEAR.. 12-2038 NET SALVAGE PERCENT.. 0 1983 10,000.00 6,937 3,259 6,741 17.00 397 2020 279,111.15 22,630 10,632 268,479 17.00 15,793 289,111.15 29,567 13,891 275,220 16,190 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 17.0 5.60 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-4 Attachment C J. Spanos, Avista Page 484 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 311.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 KETTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 75-S1.5 PROBABLE RETIREMENT YEAR.. 12-2038 NET SALVAGE PERCENT.. -5 1983 19,438,723.86 14,244,191 18,190,493 2,220,167 15.68 141,592 1984 45,988.97 33,426 42,687 5,602 15.74 356 1985 579,051.87 417,407 533,048 74,956 15.79 4,747 1986 82,675.22 59,057 75,419 11,390 15.85 719 1987 18,470.17 13,073 16,695 2,699 15.90 170 1989 130,640.34 90,643 115,755 21,417 16.00 1,339 1992 37,117.47 24,883 31,777 7,197 16.15 446 1994 1,751.62 1,144 1,461 378 16.24 23 2001 9,987.39 5,766 7,363 3,123 16.52 189 2002 54,559.78 30,789 39,319 17,969 16.55 1,086 2003 747.01 411 525 259 16.58 16 2005 1,920.62 999 1,276 741 16.65 45 2007 40,820.57 19,846 25,344 17,517 16.70 1,049 2008 373,413.39 174,446 222,776 169,308 16.73 10,120 2009 21,777.27 9,737 12,435 10,432 16.76 622 2010 236,067.08 100,536 128,389 119,481 16.78 7,120 2012 104,084.80 39,367 50,273 59,016 16.82 3,509 2014 170,984.38 55,225 70,525 109,009 16.86 6,466 2015 2,597,860.62 757,524 967,393 1,760,360 16.88 104,287 2016 487,892.48 125,613 160,414 351,873 16.90 20,821 2017 263,027.18 58,047 74,129 202,050 16.91 11,949 2018 244,530.79 43,882 56,039 200,718 16.93 11,856 2019 45,351.03 6,124 7,821 39,798 16.94 2,349 2020 84,377.21 7,203 9,199 79,398 16.95 4,684 2021 216,451.07 6,509 8,312 218,961 16.96 12,910 25,288,272.19 16,325,848 20,848,866 5,703,820 348,470 COLSTRIP 3 AND COMMON - IDAHO INTERIM SURVIVOR CURVE.. IOWA 75-S1.5 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -3 1984 16,491,756.21 14,620,968 15,096,613 1,889,895 5.86 322,508 1985 137,682.86 121,608 125,564 16,249 5.87 2,768 1987 240,876.56 211,096 217,963 30,140 5.88 5,126 1988 967.63 844 871 125 5.89 21 1989 183,788.73 159,614 164,807 24,496 5.90 4,152 1990 14,886.04 12,868 13,287 2,046 5.90 347 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-5 Attachment C J. Spanos, Avista Page 485 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 311.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 3 AND COMMON - IDAHO INTERIM SURVIVOR CURVE.. IOWA 75-S1.5 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -3 1991 37,591.79 32,324 33,376 5,344 5.91 904 1992 14,811.06 12,669 13,081 2,174 5.91 368 1993 20,578.84 17,497 18,066 3,130 5.92 529 1994 7,781.77 6,577 6,791 1,224 5.92 207 1998 18,751.35 15,384 15,884 3,429 5.94 577 1999 4,489.67 3,650 3,769 856 5.95 144 2000 4,349.61 3,502 3,616 864 5.95 145 2001 44,043.35 35,080 36,221 9,143 5.96 1,534 2002 40,910.53 32,219 33,267 8,871 5.96 1,488 2004 50,376.21 38,632 39,889 11,999 5.97 2,010 2005 4,831.25 3,649 3,768 1,208 5.97 202 2006 73.11 54 56 20 5.97 3 2007 5.20 4 4 1 5.98 2008 15,589.04 11,118 11,480 4,577 5.98 765 2009 14,065.83 9,792 10,111 4,377 5.98 732 2010 17,332.63 11,738 12,120 5,733 5.98 959 2011 103,196.76 67,635 69,835 36,457 5.99 6,086 2012 41,913.55 26,455 27,316 15,855 5.99 2,647 2017 2,186,046.33 963,764 995,117 1,256,511 6.00 209,418 2018 83,607.41 31,727 32,759 53,356 6.00 8,893 2019 41,099.75 12,451 12,856 29,477 6.00 4,913 2020 57,222.52 11,788 12,171 46,768 6.00 7,795 2021 274,110.49 21,717 22,423 259,910 6.00 43,318 20,152,736.08 16,496,424 17,033,081 3,724,237 628,559 COLSTRIP 3 AND COMMON - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 75-S1.5 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -3 1900 25,184.57 24,810 25,080 860 3.26 264 1984 31,103,499.80 28,905,988 29,220,396 2,816,209 3.94 714,774 1985 259,670.28 240,728 243,346 24,114 3.94 6,120 1987 454,293.89 418,791 423,346 44,577 3.95 11,285 1988 1,824.96 1,677 1,695 184 3.95 47 1989 346,626.07 317,509 320,963 36,062 3.96 9,107 1990 28,075.11 25,632 25,911 3,007 3.96 759 1991 70,898.22 64,499 65,201 7,825 3.96 1,976 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-6 Attachment C J. Spanos, Avista Page 486 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 311.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 3 AND COMMON - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 75-S1.5 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -3 1992 27,933.71 25,318 25,593 3,178 3.96 803 1993 38,811.74 35,023 35,404 4,572 3.97 1,152 1994 14,676.44 13,187 13,330 1,786 3.97 450 1998 35,365.10 31,108 31,446 4,980 3.98 1,251 1999 8,467.53 7,401 7,482 1,240 3.98 312 2000 8,203.39 7,121 7,198 1,251 3.98 314 2001 83,065.89 71,573 72,351 13,206 3.98 3,318 2002 77,157.37 65,938 66,655 12,817 3.98 3,220 2004 95,009.68 79,623 80,489 17,371 3.99 4,354 2005 9,111.75 7,551 7,633 1,752 3.99 439 2006 137.89 113 114 28 3.99 7 2007 9.80 8 8 2 3.99 1 2008 29,400.96 23,363 23,617 6,666 3.99 1,671 2009 26,528.17 20,704 20,929 6,395 3.99 1,603 2010 32,689.37 24,986 25,258 8,412 3.99 2,108 2011 194,629.30 145,229 146,809 53,660 3.99 13,449 2012 53,864.48 39,017 39,441 16,039 4.00 4,010 2017 4,122,889.67 2,248,180 2,272,633 1,973,943 4.00 493,486 2018 144,795.04 69,599 70,356 78,783 4.00 19,696 2019 90,403.03 35,814 36,204 56,912 4.00 14,228 2020 108,112.75 30,370 30,700 80,656 4.00 20,164 2021 521,608.11 59,695 60,344 476,912 4.00 119,228 38,012,944.07 33,040,555 33,399,934 5,753,398 1,449,596 COLSTRIP 4 - IDAHO INTERIM SURVIVOR CURVE.. IOWA 75-S1.5 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -4 1986 16,590,120.92 14,737,615 15,344,807 1,908,918 5.88 324,646 1987 12,672.74 11,214 11,676 1,504 5.88 256 1989 14,929.96 13,092 13,631 1,896 5.90 321 1990 17,733.17 15,478 16,116 2,327 5.90 394 1991 30,760.14 26,706 27,806 4,184 5.91 708 1992 52,524.57 45,364 47,233 7,393 5.91 1,251 1993 18,983.78 16,297 16,968 2,775 5.92 469 1994 8,438.40 7,201 7,498 1,278 5.92 216 1997 616.31 515 536 105 5.94 18 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-7 Attachment C J. Spanos, Avista Page 487 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 311.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 4 - IDAHO INTERIM SURVIVOR CURVE.. IOWA 75-S1.5 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -4 1998 1,283.87 1,064 1,108 227 5.94 38 1999 4,489.67 3,685 3,837 832 5.95 140 2000 8,481.97 6,896 7,180 1,641 5.95 276 2001 15,329.55 12,329 12,837 3,106 5.96 521 2002 40,910.53 32,532 33,872 8,675 5.96 1,456 2003 179,267.90 140,806 146,607 39,831 5.96 6,683 2004 55,771.54 43,185 44,964 13,038 5.97 2,184 2005 4,831.25 3,685 3,837 1,188 5.97 199 2006 73.11 55 57 19 5.97 3 2007 5.20 4 4 1 5.98 2008 15,589.39 11,226 11,689 4,524 5.98 757 2009 14,065.83 9,887 10,294 4,334 5.98 725 2010 17,332.63 11,852 12,340 5,686 5.98 951 2011 93,920.58 62,153 64,714 32,964 5.99 5,503 2012 35,882.89 22,869 23,811 13,507 5.99 2,255 2017 1,119,824.18 498,491 519,029 645,588 6.00 107,598 2018 88,135.38 33,770 35,161 56,499 6.00 9,416 2019 78,352.00 23,967 24,954 56,532 6.00 9,422 2020 46,675.20 9,708 10,108 38,434 6.00 6,406 2021 209,412.64 16,752 17,442 200,347 6.00 33,391 18,776,415.30 15,818,398 16,470,119 3,057,353 516,203 COLSTRIP 4 - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 75-S1.5 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -4 1986 31,289,015.93 29,203,866 28,661,194 3,879,383 3.95 982,122 1987 23,900.82 22,247 21,834 3,023 3.95 765 1989 28,157.95 26,043 25,559 3,725 3.96 941 1990 33,444.81 30,831 30,258 4,525 3.96 1,143 1991 58,013.71 53,290 52,300 8,035 3.96 2,029 1992 99,061.49 90,657 88,972 14,052 3.96 3,548 1993 35,803.47 32,622 32,016 5,220 3.97 1,315 1994 15,914.85 14,439 14,171 2,381 3.97 600 1997 1,162.37 1,039 1,020 189 3.97 48 1998 2,421.37 2,151 2,111 407 3.98 102 1999 8,467.54 7,473 7,334 1,472 3.98 370 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-8 Attachment C J. Spanos, Avista Page 488 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 311.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 4 - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 75-S1.5 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -4 2000 15,997.03 14,022 13,761 2,875 3.98 722 2001 28,911.58 25,153 24,686 5,382 3.98 1,352 2002 77,157.37 66,578 65,341 14,903 3.98 3,744 2003 338,099.79 289,119 283,747 67,877 3.98 17,055 2004 105,185.29 89,006 87,352 22,041 3.99 5,524 2005 9,111.75 7,625 7,483 1,993 3.99 499 2006 137.89 114 112 32 3.99 8 2007 9.80 8 8 2 3.99 1 2008 29,401.61 23,590 23,152 7,426 3.99 1,861 2009 26,528.17 20,906 20,518 7,072 3.99 1,772 2010 32,689.37 25,228 24,759 9,238 3.99 2,315 2011 177,134.47 133,458 130,978 53,242 3.99 13,344 2012 67,675.22 49,497 48,577 21,805 4.00 5,451 2017 2,111,991.63 1,162,834 1,141,226 1,055,245 4.00 263,811 2018 149,732.74 72,671 71,321 84,401 4.00 21,100 2019 164,262.96 65,706 64,485 106,348 4.00 26,587 2020 88,185.22 25,013 24,548 67,164 4.00 16,791 2021 399,397.74 46,152 45,294 370,079 4.00 92,520 35,416,973.94 31,601,338 31,014,115 5,819,538 1,467,440 137,647,341.58 113,282,563 118,766,116 24,058,346 4,410,268 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 5.5 3.20 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-9 Attachment C J. Spanos, Avista Page 489 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 311.10 STRUCTURES AND IMPROVEMENTS - LANDFILL CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 KETTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 55-S3 PROBABLE RETIREMENT YEAR.. 12-2038 NET SALVAGE PERCENT.. 0 1990 883,460.44 593,677 794,378 89,082 15.00 5,939 1991 753,698.55 499,619 668,523 85,176 15.18 5,611 1993 1,006,829.80 648,499 867,734 139,096 15.51 8,968 1999 308,503.84 178,611 238,993 69,511 16.29 4,267 2003 560,042.04 294,862 394,545 165,498 16.62 9,958 2004 24,078.00 12,317 16,481 7,597 16.69 455 2005 27,901.73 13,846 18,527 9,375 16.74 560 2007 17,536.29 8,113 10,856 6,681 16.83 397 2008 10,395.19 4,622 6,185 4,211 16.86 250 2009 14,860.89 6,320 8,457 6,404 16.89 379 2010 8,241.15 3,336 4,464 3,777 16.91 223 2011 16,864.72 6,456 8,639 8,226 16.93 486 2012 669.38 240 321 348 16.95 21 2021 15,769.14 451 603 15,166 17.00 892 3,648,851.16 2,270,969 3,038,704 610,147 38,406 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 15.9 1.05 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-10 Attachment C J. Spanos, Avista Page 490 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 312.00 BOILER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 KETTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 55-R1 PROBABLE RETIREMENT YEAR.. 12-2038 NET SALVAGE PERCENT.. -5 1983 28,203,333.08 19,835,418 23,151,897 6,461,602 14.72 438,968 1984 287,713.29 200,669 234,221 67,878 14.79 4,589 1986 873,028.19 598,033 698,024 218,656 14.93 14,645 1987 13,547.23 9,190 10,727 3,498 15.00 233 1988 18,631.24 12,515 14,608 4,955 15.06 329 1990 58,645.05 38,554 45,000 16,577 15.18 1,092 1992 262,878.38 168,771 196,989 79,033 15.29 5,169 1994 65,243.65 40,779 47,597 20,909 15.40 1,358 1995 101,877.17 62,798 73,298 33,673 15.44 2,181 1998 1,159,154.25 680,232 793,967 423,145 15.58 27,159 2000 3,442.15 1,944 2,269 1,345 15.66 86 2001 188,672.94 104,311 121,752 76,355 15.70 4,863 2002 41,091.12 22,212 25,926 17,220 15.73 1,095 2003 68,015.41 35,844 41,837 29,579 15.77 1,876 2004 22,006.69 11,292 13,180 9,927 15.80 628 2005 395,813.71 197,250 230,230 185,374 15.83 11,710 2006 189,882.51 91,639 106,961 92,416 15.86 5,827 2007 114,691.56 53,448 62,384 58,042 15.89 3,653 2008 162,245.77 72,695 84,850 85,508 15.92 5,371 2009 576,445.13 247,403 288,769 316,499 15.94 19,856 2010 940,141.14 384,287 448,540 538,608 15.97 33,726 2011 138,659.27 53,684 62,660 82,932 15.99 5,186 2012 1,174,339.48 426,465 497,770 735,287 16.02 45,898 2013 564,965.02 191,050 222,994 370,220 16.04 23,081 2014 2,381,170.49 738,768 862,290 1,637,939 16.07 101,925 2015 1,174,024.48 329,508 384,602 848,124 16.09 52,711 2016 154,794.18 38,379 44,796 117,738 16.11 7,308 2017 537,458.92 114,373 133,496 430,836 16.13 26,710 2018 3,536,228.20 614,025 716,690 2,996,350 16.15 185,533 2019 2,187,766.31 284,801 332,420 1,964,735 16.18 121,430 2020 362,385.17 29,870 34,864 345,640 16.20 21,336 2021 843,394.42 24,424 28,508 857,056 16.22 52,839 46,801,685.60 25,714,631 30,014,114 19,127,656 1,228,371 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-11 Attachment C J. Spanos, Avista Page 491 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 312.00 BOILER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 3 AND COMMON - IDAHO INTERIM SURVIVOR CURVE.. IOWA 55-R1 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -3 1984 21,877,622.96 19,074,539 19,891,813 2,642,139 5.74 460,303 1985 50,813.63 44,140 46,031 6,307 5.75 1,097 1986 315,401.86 272,915 284,608 40,256 5.76 6,989 1987 296,579.64 255,574 266,524 38,953 5.77 6,751 1988 38,365.12 32,917 34,327 5,189 5.78 898 1989 83,008.56 70,917 73,956 11,543 5.78 1,997 1990 22,718.96 19,315 20,143 3,258 5.79 563 1991 65,530.20 55,421 57,796 9,701 5.80 1,673 1992 24,429.90 20,553 21,434 3,729 5.80 643 1993 14,694.33 12,289 12,816 2,320 5.81 399 1994 4,890.06 4,064 4,238 799 5.82 137 1995 10,724.90 8,856 9,235 1,811 5.82 311 1996 28,147.85 23,076 24,065 4,928 5.83 845 1997 23,694.32 19,282 20,108 4,297 5.83 737 1999 33,301.62 26,640 27,781 6,519 5.84 1,116 2000 42,431.70 33,611 35,051 8,654 5.85 1,479 2001 338,431.67 265,318 276,686 71,899 5.85 12,290 2002 112,677.87 87,363 91,106 24,952 5.85 4,265 2003 189,234.02 144,838 151,044 43,867 5.86 7,486 2004 443,828.36 335,155 349,515 107,628 5.86 18,367 2005 154,735.65 115,093 120,024 39,353 5.86 6,716 2006 149,466.25 109,280 113,962 39,988 5.87 6,812 2007 317,932.98 228,129 237,903 89,567 5.87 15,258 2008 254,858.56 179,078 186,751 75,753 5.87 12,905 2009 271,110.25 185,845 193,808 85,436 5.88 14,530 2010 211,861.53 141,291 147,345 70,873 5.88 12,053 2011 156,682.91 101,249 105,587 55,796 5.88 9,489 2012 5,129.26 3,190 3,327 1,956 5.89 332 2016 133,878.22 64,994 67,779 70,116 5.90 11,884 2017 2,637,816.94 1,148,455 1,197,662 1,519,289 5.90 257,507 2018 927,711.59 347,378 362,262 593,281 5.90 100,556 2019 455,167.17 135,799 141,617 327,205 5.91 55,365 2020 154,022.56 31,254 32,593 126,050 5.91 21,328 2021 577,899.73 45,571 47,524 547,713 5.91 92,676 30,424,801.13 23,643,389 24,656,421 6,681,124 1,145,757 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-12 Attachment C J. Spanos, Avista Page 492 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 312.00 BOILER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 3 AND COMMON - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 55-R1 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -3 1984 41,261,260.04 37,909,195 38,868,558 3,630,540 3.89 933,301 1985 95,834.64 87,838 90,061 8,649 3.89 2,223 1986 594,848.80 543,656 557,414 55,280 3.90 14,174 1987 559,350.07 509,829 522,731 53,399 3.90 13,692 1988 72,356.72 65,762 67,426 7,101 3.90 1,821 1989 156,554.39 141,804 145,393 15,858 3.91 4,056 1990 42,848.02 38,683 39,662 4,472 3.91 1,144 1991 123,590.16 111,190 114,004 13,294 3.91 3,400 1992 46,074.87 41,299 42,344 5,113 3.91 1,308 1993 27,713.55 24,732 25,358 3,187 3.92 813 1994 9,222.66 8,196 8,403 1,096 3.92 280 1995 20,227.19 17,893 18,346 2,488 3.92 635 1996 53,086.94 46,729 47,912 6,768 3.92 1,727 1997 44,687.55 39,111 40,101 5,927 3.93 1,508 1999 62,806.96 54,310 55,684 9,007 3.93 2,292 2000 80,026.30 68,736 70,475 11,952 3.93 3,041 2001 638,283.12 544,163 557,934 99,498 3.93 25,318 2002 212,510.78 179,614 184,159 34,727 3.94 8,814 2003 356,895.91 298,927 306,492 61,111 3.94 15,510 2004 837,061.58 694,257 711,826 150,347 3.94 38,159 2005 291,831.85 239,381 245,439 55,148 3.94 13,997 2006 281,893.75 228,413 234,193 56,157 3.94 14,253 2007 599,622.52 479,192 491,319 126,292 3.94 32,054 2008 480,663.94 378,140 387,710 107,374 3.94 27,252 2009 511,314.75 394,822 404,814 121,840 3.95 30,846 2010 399,571.47 302,232 309,881 101,678 3.95 25,741 2011 295,504.42 218,187 223,709 80,661 3.95 20,421 2012 9,673.77 6,943 7,119 2,845 3.95 720 2016 252,494.70 149,251 153,028 107,041 3.95 27,099 2017 3,541,437.37 1,911,530 1,959,905 1,687,776 3.96 426,206 2018 1,461,846.39 695,574 713,177 792,525 3.96 200,133 2019 1,146,266.95 450,125 461,516 719,139 3.96 181,601 2020 291,000.76 81,143 83,196 216,534 3.96 54,680 2021 1,102,499.89 125,038 128,202 1,007,373 3.96 254,387 55,960,862.78 47,085,895 48,277,491 9,362,198 2,382,606 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-13 Attachment C J. Spanos, Avista Page 493 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 312.00 BOILER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 4 - IDAHO INTERIM SURVIVOR CURVE.. IOWA 55-R1 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -4 1986 12,931,872.47 11,298,494 11,465,449 1,983,699 5.76 344,392 1987 201,100.73 174,979 177,565 31,580 5.77 5,473 1989 30,379.15 26,206 26,593 5,001 5.78 865 1990 54,569.00 46,842 47,534 9,218 5.79 1,592 1991 33,203.76 28,354 28,773 5,759 5.80 993 1992 34,484.50 29,294 29,727 6,137 5.80 1,058 1993 3,138.00 2,650 2,689 574 5.81 99 1994 16,775.79 14,077 14,285 3,162 5.82 543 1995 10,435.91 8,701 8,830 2,024 5.82 348 1996 39,119.84 32,383 32,862 7,823 5.83 1,342 1999 17,733.51 14,324 14,536 3,907 5.84 669 2000 85,099.01 68,063 69,069 19,434 5.85 3,322 2001 31,825.73 25,192 25,564 7,535 5.85 1,288 2002 274,896.60 215,206 218,386 67,506 5.85 11,539 2003 358,680.64 277,197 281,293 91,735 5.86 15,654 2004 329,976.00 251,599 255,317 87,858 5.86 14,993 2005 244,839.50 183,881 186,598 68,035 5.86 11,610 2006 167,490.46 123,647 125,474 48,716 5.87 8,299 2007 182,998.61 132,584 134,543 55,775 5.87 9,502 2008 241,465.29 171,314 173,845 77,278 5.87 13,165 2009 698,661.81 483,580 490,726 235,883 5.88 40,116 2010 257,168.15 173,172 175,731 91,724 5.88 15,599 2011 169,970.35 110,901 112,540 64,229 5.88 10,923 2012 28,307.84 17,779 18,042 11,398 5.89 1,935 2016 471,107.28 230,929 234,341 255,610 5.90 43,324 2017 2,144,257.10 942,633 956,562 1,273,465 5.90 215,842 2018 942,758.90 356,440 361,707 618,762 5.90 104,875 2019 490,554.28 147,778 149,962 360,215 5.91 60,950 2020 197,093.66 40,383 40,980 163,998 5.91 27,749 2021 875,621.38 69,719 70,749 839,897 5.91 142,115 21,565,585.25 15,698,301 15,930,270 6,497,938 1,110,174 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-14 Attachment C J. Spanos, Avista Page 494 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 312.00 BOILER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 4 - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 55-R1 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -4 1986 24,389,548.78 22,506,988 21,266,113 4,099,018 3.90 1,051,030 1987 379,276.55 349,055 329,811 64,637 3.90 16,574 1989 57,295.16 52,401 49,512 10,075 3.91 2,577 1990 102,917.28 93,815 88,643 18,391 3.91 4,704 1991 62,622.39 56,886 53,750 11,378 3.91 2,910 1992 65,037.88 58,862 55,617 12,023 3.91 3,075 1993 5,918.29 5,333 5,039 1,116 3.92 285 1994 31,639.18 28,390 26,825 6,080 3.92 1,551 1995 19,682.16 17,580 16,611 3,859 3.92 984 1996 73,780.12 65,575 61,960 14,772 3.92 3,768 1999 33,445.46 29,202 27,592 7,191 3.93 1,830 2000 160,496.99 139,192 131,518 35,399 3.93 9,007 2001 60,023.42 51,669 48,820 13,604 3.93 3,462 2002 518,455.78 442,452 418,058 121,136 3.94 30,745 2003 676,472.71 572,098 540,557 162,975 3.94 41,364 2004 622,335.70 521,175 492,441 154,788 3.94 39,286 2005 461,768.00 382,453 361,367 118,871 3.94 30,170 2006 315,887.54 258,443 244,194 84,329 3.94 21,403 2007 345,135.89 278,495 263,141 95,801 3.94 24,315 2008 455,404.21 361,747 341,803 131,818 3.94 33,456 2009 1,317,678.19 1,027,350 970,709 399,676 3.95 101,184 2010 485,019.85 370,426 350,003 154,417 3.95 39,093 2011 320,564.54 238,989 225,813 107,574 3.95 27,234 2012 53,388.66 38,692 36,559 18,965 3.95 4,801 2016 888,509.67 530,303 501,066 422,984 3.95 107,085 2017 2,741,338.07 1,494,034 1,411,664 1,439,328 3.96 363,467 2018 1,427,766.50 685,954 648,135 836,742 3.96 211,298 2019 1,275,466.32 505,722 477,840 848,645 3.96 214,304 2020 372,376.59 104,842 99,062 288,210 3.96 72,780 2021 1,672,639.65 191,541 180,981 1,558,564 3.96 393,577 39,391,891.53 31,459,664 29,725,202 11,242,365 2,857,319 194,144,826.29 143,601,880 148,603,498 52,911,281 8,724,227 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 6.1 4.49 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-15 Attachment C J. Spanos, Avista Page 495 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 313.00 ENGINES AND ENGINE-DRIVEN GENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 3 AND COMMON - IDAHO INTERIM SURVIVOR CURVE.. IOWA 50-R2.5 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -3 2011 1,172.90 766 661 547 5.95 92 2021 174,287.75 13,595 11,732 167,784 5.98 28,058 175,460.65 14,361 12,394 168,331 28,150 COLSTRIP 3 AND COMMON - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 50-R2.5 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -3 2011 2,212.10 1,646 1,543 736 3.98 185 2021 330,910.55 37,956 35,577 305,261 3.99 76,507 333,122.65 39,602 37,119 305,997 76,692 COLSTRIP 4 - IDAHO INTERIM SURVIVOR CURVE.. IOWA 50-R2.5 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -4 2011 1,172.90 773 1,220 2021 10,221.39 805 6,604 4,026 5.98 673 11,394.29 1,578 7,824 4,026 673 COLSTRIP 4 - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 50-R2.5 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -4 2011 2,212.10 1,662 2,301 2021 18,870.62 2,185 24,178 4,553 - 21,082.72 3,847 26,479 4,553 - 541,060.31 59,388 83,816 473,801 105,515 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 4.5 19.50 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-16 Attachment C J. Spanos, Avista Page 496 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 314.00 TURBOGENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 KETTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 37-R0.5 PROBABLE RETIREMENT YEAR.. 12-2038 NET SALVAGE PERCENT.. -5 1983 10,985,668.05 7,642,136 9,691,308 1,843,643 11.94 154,409 1988 67,815.27 44,650 56,623 14,584 12.74 1,145 1993 1,769.00 1,092 1,385 473 13.41 35 1994 583,202.46 354,736 449,855 162,507 13.53 12,011 1998 273,930.09 155,799 197,575 90,051 13.97 6,446 1999 18,428.50 10,278 13,034 6,316 14.07 449 2003 127,085.31 64,646 81,980 51,459 14.43 3,566 2007 30,962.40 13,877 17,598 14,913 14.73 1,012 2009 121,846.55 50,213 63,677 64,262 14.86 4,324 2011 71,733.33 26,635 33,777 41,543 14.97 2,775 2014 478,816.20 142,486 180,692 322,065 15.12 21,301 2015 239,967.65 64,629 81,959 170,007 15.16 11,214 2017 4,377,326.20 891,523 1,130,577 3,465,615 15.25 227,253 2018 66,004.34 10,953 13,890 55,415 15.29 3,624 2019 881,266.84 110,142 139,676 785,655 15.32 51,283 2020 306,266.71 24,202 30,692 290,888 15.36 18,938 18,632,088.90 9,607,997 12,184,298 7,379,396 519,785 COLSTRIP 3 AND COMMON - IDAHO INTERIM SURVIVOR CURVE.. IOWA 37-R0.5 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -3 1984 3,735,579.08 3,194,855 3,440,649 406,997 5.39 75,510 1985 5,076.70 4,325 4,658 571 5.42 105 1987 2,862.61 2,420 2,606 342 5.46 63 1988 12,477.50 10,505 11,313 1,539 5.48 281 1989 10,989.13 9,211 9,920 1,399 5.50 254 1990 14,243.55 11,882 12,796 1,875 5.52 340 1991 13,843.18 11,489 12,373 1,886 5.54 340 1992 137,169.93 113,220 121,931 19,355 5.56 3,481 1993 193,196.13 158,599 170,801 28,191 5.57 5,061 1994 85,200.87 69,507 74,854 12,902 5.59 2,308 1995 73,037.69 59,210 63,765 11,464 5.60 2,047 1996 17,825.90 14,346 15,450 2,911 5.62 518 1997 19,647.87 15,696 16,904 3,334 5.63 592 1998 55,859.50 44,269 47,675 9,860 5.64 1,748 2001 40,020.06 30,810 33,180 8,040 5.68 1,415 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-17 Attachment C J. Spanos, Avista Page 497 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 314.00 TURBOGENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 3 AND COMMON - IDAHO INTERIM SURVIVOR CURVE.. IOWA 37-R0.5 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -3 2002 2,200.92 1,676 1,805 462 5.69 81 2003 120,443.05 90,544 97,510 26,546 5.70 4,657 2004 295,179.11 218,893 235,733 68,301 5.71 11,962 2005 25,827.76 18,863 20,314 6,288 5.72 1,099 2006 132,752.46 95,325 102,659 34,076 5.73 5,947 2007 627,874.63 442,654 476,709 170,002 5.73 29,669 2008 82,771.23 57,114 61,508 23,746 5.74 4,137 2009 111,657.89 75,194 80,979 34,029 5.75 5,918 2010 7,642.07 5,010 5,395 2,476 5.75 431 2011 1,441,839.63 915,205 985,616 499,479 5.76 86,715 2012 128,670.11 78,734 84,791 47,739 5.76 8,288 2017 750,129.44 321,215 345,927 426,706 5.79 73,697 2020 3,919.23 785 845 3,191 5.80 550 2021 182,870.95 14,097 15,182 173,176 5.81 29,807 8,330,808.18 6,085,653 6,553,849 2,026,883 357,021 COLSTRIP 3 AND COMMON - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 37-R0.5 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -3 1984 7,045,312.92 6,381,300 5,981,447 1,275,225 3.73 341,883 1985 9,574.68 8,652 8,110 1,752 3.74 468 1987 5,398.90 4,853 4,549 1,012 3.76 269 1988 23,532.61 21,092 19,770 4,468 3.77 1,185 1989 20,725.54 18,518 17,358 3,990 3.78 1,056 1990 26,863.38 23,923 22,424 5,245 3.79 1,384 1991 26,108.28 23,168 21,716 5,175 3.80 1,362 1992 258,702.87 228,794 214,458 52,006 3.80 13,686 1993 364,368.47 320,930 300,821 74,479 3.81 19,548 1994 160,689.08 140,908 132,079 33,431 3.82 8,752 1995 137,749.29 120,224 112,691 29,191 3.83 7,622 1996 33,619.70 29,206 27,376 7,252 3.83 1,893 1997 37,055.95 32,015 30,009 8,159 3.84 2,125 1998 105,351.19 90,520 84,848 23,664 3.84 6,162 2001 75,477.96 63,520 59,540 18,202 3.86 4,716 2002 4,150.93 3,466 3,249 1,027 3.86 266 2003 227,155.95 187,914 176,139 57,831 3.87 14,943 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-18 Attachment C J. Spanos, Avista Page 498 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 314.00 TURBOGENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 3 AND COMMON - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 37-R0.5 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -3 2004 556,708.64 456,119 427,539 145,871 3.87 37,693 2005 48,711.24 39,453 36,981 13,192 3.88 3,400 2006 250,371.54 200,344 187,790 70,092 3.88 18,065 2007 1,184,173.37 934,789 876,215 343,484 3.88 88,527 2008 156,106.77 121,253 113,655 47,135 3.89 12,117 2009 210,587.11 160,692 150,623 66,282 3.89 17,039 2010 14,412.93 10,776 10,101 4,745 3.89 1,220 2011 2,719,313.68 1,985,357 1,860,954 939,939 3.89 241,630 2012 242,672.21 172,030 161,251 88,702 3.90 22,744 2018 1,414,746.29 665,848 624,126 833,063 3.91 213,060 2020 7,404.73 2,042 1,914 5,713 3.91 1,461 2021 347,307.53 38,298 35,898 321,829 3.92 82,099 15,714,353.74 12,486,004 11,703,630 4,482,154 1,166,375 COLSTRIP 4 - IDAHO INTERIM SURVIVOR CURVE.. IOWA 37-R0.5 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -4 1986 2,246,229.84 1,925,069 1,785,836 550,243 5.44 101,148 1987 7,819.65 6,676 6,193 1,939 5.46 355 1989 10,722.89 9,075 8,419 2,733 5.50 497 1990 2,312.84 1,948 1,807 598 5.52 108 1991 12,644.80 10,596 9,830 3,321 5.54 599 1992 17,943.27 14,954 13,872 4,789 5.56 861 1993 67,419.97 55,884 51,842 18,275 5.57 3,281 1994 34,990.95 28,823 26,738 9,652 5.59 1,727 1995 212,335.95 173,808 161,237 59,592 5.60 10,641 1996 284,231.12 230,958 214,254 81,347 5.62 14,475 1997 157,887.93 127,358 118,147 46,057 5.63 8,181 1998 39,787.92 31,838 29,535 11,844 5.64 2,100 1999 15,223.48 12,070 11,197 4,635 5.66 819 2000 97,286.80 76,408 70,882 30,297 5.67 5,343 2001 82,946.46 64,477 59,814 26,451 5.68 4,657 2002 34,525.29 26,539 24,620 11,287 5.69 1,984 2003 130,997.18 99,434 92,242 43,995 5.70 7,718 2004 11,870.33 8,888 8,245 4,100 5.71 718 2005 168,447.85 124,215 115,231 59,955 5.72 10,482 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-19 Attachment C J. Spanos, Avista Page 499 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 314.00 TURBOGENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 4 - IDAHO INTERIM SURVIVOR CURVE.. IOWA 37-R0.5 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -4 2006 152,006.43 110,210 102,239 55,848 5.73 9,747 2007 51,629.53 36,752 34,094 19,601 5.73 3,421 2008 70,826.31 49,347 45,778 27,881 5.74 4,857 2009 420,748.38 286,097 265,405 172,174 5.75 29,943 2010 6,926.53 4,585 4,253 2,950 5.75 513 2011 9,598.83 6,152 5,707 4,276 5.76 742 2012 7,955.58 4,915 4,560 3,714 5.76 645 2014 184,355.97 103,145 95,685 96,045 5.78 16,617 2017 664,605.90 287,355 266,572 424,618 5.79 73,336 2020 3,919.23 793 736 3,340 5.80 576 2021 809,903.70 63,038 58,479 783,821 5.81 134,909 6,018,100.91 3,981,407 3,693,446 2,565,379 451,000 COLSTRIP 4 - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 37-R0.5 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -4 1986 4,236,395.97 3,855,297 3,166,818 1,239,034 3.75 330,409 1987 14,747.89 13,385 10,995 4,343 3.76 1,155 1989 20,223.40 18,245 14,987 6,046 3.78 1,599 1990 4,362.01 3,922 3,222 1,315 3.79 347 1991 23,848.14 21,367 17,551 7,251 3.80 1,908 1992 33,841.07 30,219 24,822 10,372 3.80 2,729 1993 127,154.27 113,083 92,889 39,352 3.81 10,329 1994 65,993.04 58,431 47,996 20,636 3.82 5,402 1995 400,466.22 352,908 289,886 126,599 3.83 33,055 1996 536,060.71 470,209 386,239 171,264 3.83 44,716 1997 297,777.09 259,763 213,375 96,314 3.84 25,082 1998 75,040.13 65,102 53,476 24,566 3.84 6,397 1999 28,711.54 24,748 20,329 9,532 3.85 2,476 2000 183,483.20 157,139 129,077 61,745 3.85 16,038 2001 156,437.26 132,931 109,192 53,503 3.86 13,861 2002 65,114.81 54,899 45,095 22,624 3.86 5,861 2003 247,061.07 206,364 169,512 87,432 3.87 22,592 2004 22,387.49 18,520 15,213 8,070 3.87 2,085 2005 317,693.15 259,807 213,411 116,990 3.88 30,152 2006 286,684.57 231,628 190,264 107,888 3.88 27,806 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-20 Attachment C J. Spanos, Avista Page 500 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 314.00 TURBOGENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 4 - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 37-R0.5 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -4 2007 97,373.47 77,613 63,753 37,516 3.88 9,669 2008 133,578.69 104,762 86,054 52,868 3.89 13,591 2009 793,532.62 611,396 502,213 323,061 3.89 83,049 2010 13,063.47 9,862 8,101 5,485 3.89 1,410 2011 18,103.41 13,346 10,963 7,865 3.89 2,022 2012 15,004.22 10,740 8,822 6,782 3.90 1,739 2014 347,695.88 230,902 189,668 171,936 3.90 44,086 2017 1,253,448.65 675,871 555,174 748,413 3.91 191,410 2020 7,404.73 2,062 1,694 6,007 3.91 1,536 2021 1,538,363.36 171,285 140,697 1,459,201 3.92 372,245 11,361,051.53 8,255,806 6,781,484 5,034,010 1,304,756 60,056,403.26 40,416,867 40,916,707 21,487,822 3,798,937 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 5.7 6.33 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-21 Attachment C J. Spanos, Avista Page 501 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 315.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 KETTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 50-S1 PROBABLE RETIREMENT YEAR.. 12-2038 NET SALVAGE PERCENT.. -5 1983 5,991,076.91 4,394,257 4,652,762 1,637,868 13.40 122,229 1984 446,300.13 324,858 343,969 124,646 13.51 9,226 1985 647,237.29 467,197 494,681 184,918 13.63 13,567 1986 13,182.92 9,436 9,991 3,851 13.74 280 1994 70,641.79 46,408 49,138 25,036 14.58 1,717 1995 35,183.22 22,798 24,139 12,803 14.68 872 2003 49,245.22 27,412 29,025 22,683 15.44 1,469 2008 90,296.04 42,768 45,284 49,527 15.88 3,119 2009 537,541.47 243,846 258,191 306,228 15.96 19,187 2012 375,685.56 144,005 152,477 241,993 16.21 14,929 2013 619,791.06 221,148 234,158 416,623 16.28 25,591 2014 115,327.43 37,750 39,971 81,123 16.36 4,959 2015 1,070,017.13 316,371 334,982 788,536 16.43 47,994 2016 642,330.05 167,998 177,881 496,566 16.49 30,113 2017 993,010.90 222,014 235,075 807,587 16.56 48,767 2018 398,203.85 72,564 76,833 341,281 16.62 20,534 2020 283,713.26 24,511 25,953 271,946 16.73 16,255 2021 217,264.78 6,602 6,990 221,138 16.78 13,179 12,596,049.01 6,791,943 7,191,500 6,034,352 393,987 COLSTRIP 3 AND COMMON - IDAHO INTERIM SURVIVOR CURVE.. IOWA 50-S1 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -3 1984 2,668,969.62 2,348,944 2,397,769 351,270 5.58 62,952 1985 789.12 692 706 106 5.60 19 1986 80,025.11 69,952 71,406 11,020 5.61 1,964 1987 4,792.76 4,173 4,260 677 5.63 120 1988 4,949.88 4,294 4,383 715 5.64 127 1990 1,552.00 1,335 1,363 236 5.67 42 1991 2,403.91 2,057 2,100 376 5.69 66 1992 206.87 176 180 33 5.70 6 1993 5,465.68 4,627 4,723 906 5.72 158 1994 1,507.06 1,268 1,294 258 5.73 45 1995 466.71 390 398 83 5.74 14 1996 1,053.20 875 893 192 5.76 33 1997 2,437.61 2,010 2,052 459 5.77 80 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-22 Attachment C J. Spanos, Avista Page 502 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 315.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 3 AND COMMON - IDAHO INTERIM SURVIVOR CURVE.. IOWA 50-S1 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -3 1998 6,026.67 4,931 5,033 1,174 5.78 203 1999 1,703.27 1,382 1,411 344 5.79 59 2000 45.25 36 37 10 5.81 2 2004 54,527.29 41,797 42,666 13,497 5.85 2,307 2005 113,625.33 85,804 87,588 29,447 5.86 5,025 2006 274,453.29 203,684 207,918 74,769 5.88 12,716 2007 17,996.86 13,108 13,380 5,156 5.89 875 2009 1,860.71 1,295 1,322 595 5.91 101 2010 1,182.95 801 818 401 5.92 68 2011 58,164.95 38,141 38,934 20,976 5.93 3,537 2017 43,273.52 19,157 19,555 25,017 5.97 4,190 2018 94,189.79 35,818 36,563 60,453 5.98 10,109 2019 35,160.73 10,634 10,855 25,361 5.99 4,234 2020 37,264.40 7,687 7,847 30,536 5.99 5,098 2021 361,845.77 28,713 29,310 343,391 5.99 57,327 3,875,940.31 2,933,781 2,994,762 997,457 171,477 COLSTRIP 3 AND COMMON - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 50-S1 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -3 1984 5,033,684.40 4,650,412 4,576,390 608,305 3.82 159,242 1985 1,488.10 1,372 1,350 183 3.82 48 1986 150,927.58 138,797 136,588 18,868 3.83 4,926 1987 9,039.15 8,290 8,158 1,152 3.84 300 1988 9,335.49 8,540 8,404 1,211 3.84 315 1990 2,927.09 2,661 2,619 396 3.86 103 1991 4,533.79 4,108 4,043 627 3.86 162 1992 390.17 352 346 55 3.87 14 1993 10,308.30 9,269 9,121 1,496 3.88 386 1994 2,842.33 2,546 2,505 422 3.88 109 1995 880.22 785 773 134 3.89 34 1996 1,986.33 1,763 1,735 311 3.89 80 1997 4,597.33 4,058 3,993 742 3.90 190 1998 11,366.32 9,973 9,814 1,893 3.91 484 1999 3,212.38 2,802 2,757 551 3.91 141 2000 85.33 74 73 15 3.92 4 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-23 Attachment C J. Spanos, Avista Page 503 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 315.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 3 AND COMMON - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 50-S1 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -3 2004 102,838.63 86,089 84,719 21,205 3.94 5,382 2005 214,297.67 177,482 174,657 46,070 3.94 11,693 2006 517,619.71 423,293 416,555 116,593 3.95 29,517 2007 33,942.14 27,385 26,949 8,011 3.95 2,028 2009 3,509.29 2,737 2,693 921 3.96 233 2010 2,231.05 1,704 1,677 621 3.97 156 2011 109,699.24 81,817 80,515 32,476 3.97 8,180 2018 198,133.54 95,363 93,845 110,232 3.99 27,627 2019 193,749.46 76,566 75,347 124,215 4.00 31,054 2020 70,405.05 19,778 19,463 53,054 4.00 13,264 2021 689,214.03 78,876 77,621 632,270 4.00 158,068 7,383,244.12 5,916,892 5,822,711 1,782,030 453,740 COLSTRIP 4 - IDAHO INTERIM SURVIVOR CURVE.. IOWA 50-S1 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -4 1986 1,835,308.81 1,619,855 1,581,168 327,553 5.61 58,387 1987 5,420.35 4,765 4,651 986 5.63 175 1989 1,968.92 1,717 1,676 372 5.66 66 1990 1,754.79 1,524 1,488 337 5.67 59 1991 2,403.91 2,077 2,027 473 5.69 83 1992 213.95 184 180 43 5.70 8 1993 877.93 750 732 181 5.72 32 1994 3,049.83 2,592 2,530 642 5.73 112 1995 1,295.97 1,094 1,068 280 5.74 49 1996 1,053.19 883 862 233 5.76 40 1997 390.53 325 317 89 5.77 15 1998 5,999.51 4,956 4,838 1,402 5.78 243 1999 1,703.28 1,395 1,362 410 5.79 71 2000 45.25 37 36 11 5.81 2 2004 54,527.29 42,203 41,195 15,513 5.85 2,652 2005 111,192.54 84,782 82,757 32,883 5.86 5,611 2006 271,250.60 203,262 198,407 83,693 5.88 14,234 2007 6,403.73 4,709 4,597 2,063 5.89 350 2009 6,120.75 4,302 4,199 2,166 5.91 366 2017 71,865.81 32,123 31,356 43,385 5.97 7,267 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-24 Attachment C J. Spanos, Avista Page 504 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 315.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 4 - IDAHO INTERIM SURVIVOR CURVE.. IOWA 50-S1 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -4 2018 90,701.75 34,827 33,995 60,335 5.98 10,089 2019 35,160.91 10,737 10,481 26,087 5.99 4,355 2020 36,369.14 7,575 7,394 30,430 5.99 5,080 2021 132,678.18 10,630 10,376 127,609 5.99 21,304 2,677,756.92 2,077,304 2,027,692 757,176 130,650 COLSTRIP 4 - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 50-S1 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -4 1986 3,461,397.71 3,214,093 2,989,707 610,147 3.83 159,307 1987 10,222.81 9,467 8,806 1,826 3.84 476 1989 3,713.39 3,420 3,181 681 3.85 177 1990 3,309.55 3,038 2,826 616 3.86 160 1991 4,533.79 4,148 3,858 857 3.86 222 1992 403.51 368 342 77 3.87 20 1993 1,655.77 1,503 1,398 324 3.88 84 1994 5,751.98 5,202 4,839 1,143 3.88 295 1995 2,444.20 2,200 2,046 496 3.89 128 1996 1,986.33 1,780 1,656 410 3.89 105 1997 736.55 656 610 156 3.90 40 1998 11,315.10 10,025 9,325 2,443 3.91 625 1999 3,212.38 2,829 2,631 709 3.91 181 2000 85.33 75 70 19 3.92 5 2004 102,838.62 86,924 80,856 26,097 3.94 6,624 2005 209,709.46 175,368 163,125 54,973 3.94 13,953 2006 511,579.40 422,415 392,925 139,118 3.95 35,220 2007 12,077.27 9,839 9,152 3,408 3.95 863 2009 11,543.75 9,092 8,457 3,548 3.96 896 2017 135,539.13 74,636 69,425 71,535 3.99 17,929 2018 109,941.70 53,430 49,700 64,639 3.99 16,200 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-25 Attachment C J. Spanos, Avista Page 505 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 315.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 4 - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 50-S1 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -4 2019 61,122.94 24,389 22,686 40,882 4.00 10,220 2020 68,713.59 19,490 18,129 53,333 4.00 13,333 2021 252,807.29 29,213 27,174 235,746 4.00 58,936 4,986,641.55 4,163,600 3,872,925 1,313,182 335,999 31,519,631.91 21,883,520 21,909,590 10,884,197 1,485,853 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 7.3 4.71 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-26 Attachment C J. Spanos, Avista Page 506 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 316.00 MISCELLANEOUS POWER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 KETTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 60-R2 PROBABLE RETIREMENT YEAR.. 12-2038 NET SALVAGE PERCENT.. -5 1983 1,521,902.23 1,102,394 1,329,579 268,419 15.02 17,871 1984 24,803.23 17,813 21,484 4,559 15.11 302 1985 392,806.50 279,655 337,287 75,160 15.19 4,948 1986 16,652.52 11,746 14,167 3,318 15.27 217 1990 4,207.41 2,848 3,435 983 15.55 63 1991 9,781.31 6,544 7,893 2,378 15.62 152 1997 10,314.77 6,341 7,648 3,183 15.95 200 2000 1,832.00 1,065 1,284 639 16.09 40 2001 83,497.52 47,520 57,313 30,359 16.13 1,882 2002 7,641.00 4,250 5,126 2,897 16.17 179 2003 98,802.29 53,604 64,651 39,092 16.21 2,412 2006 18,644.01 9,260 11,168 8,408 16.31 516 2007 9,547.92 4,574 5,517 4,509 16.35 276 2008 139,153.71 64,121 77,335 68,776 16.38 4,199 2009 137,372.77 60,602 73,091 71,150 16.41 4,336 2,476,959.19 1,672,337 2,016,977 583,830 37,593 COLSTRIP 3 AND COMMON - IDAHO INTERIM SURVIVOR CURVE.. IOWA 60-R2 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -3 1984 1,434,136.73 1,263,608 1,377,924 99,237 5.79 17,139 1985 304,176.62 267,027 291,184 22,118 5.80 3,813 1986 959,614.69 839,164 915,081 73,322 5.81 12,620 1987 56,401.37 49,120 53,564 4,530 5.82 778 1988 16,198.48 14,046 15,317 1,368 5.83 235 1989 13,460.70 11,618 12,669 1,195 5.84 205 1990 12,857.64 11,047 12,046 1,197 5.84 205 1991 18,821.10 16,087 17,542 1,843 5.85 315 1992 16,455.53 13,988 15,253 1,696 5.86 289 1993 8,761.53 7,403 8,073 952 5.87 162 1994 35,669.80 29,962 32,673 4,067 5.87 693 1995 14,165.78 11,819 12,888 1,703 5.88 290 1996 8,177.18 6,776 7,389 1,033 5.88 176 1997 13,439.82 11,050 12,050 1,793 5.89 304 1998 9,798.73 7,992 8,715 1,378 5.89 234 1999 11,440.74 9,247 10,084 1,700 5.90 288 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-27 Attachment C J. Spanos, Avista Page 507 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 316.00 MISCELLANEOUS POWER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 3 AND COMMON - IDAHO INTERIM SURVIVOR CURVE.. IOWA 60-R2 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -3 2000 16,500.68 13,210 14,405 2,591 5.90 439 2001 7,723.91 6,118 6,671 1,284 5.91 217 2002 10,074.96 7,891 8,605 1,772 5.91 300 2003 12,757.24 9,865 10,757 2,382 5.92 402 2004 11,256.96 8,587 9,364 2,231 5.92 377 2005 3,819.13 2,870 3,130 804 5.92 136 2006 22,721.29 16,779 18,297 5,106 5.93 861 2007 6,723.82 4,873 5,314 1,612 5.93 272 2008 10,472.96 7,427 8,099 2,688 5.94 453 2009 9,458.05 6,548 7,140 2,601 5.94 438 2010 140.68 95 104 41 5.94 7 2011 6,739.37 4,398 4,796 2,146 5.94 361 2012 21,245.55 13,345 14,552 7,331 5.95 1,232 2016 17,503.44 8,578 9,354 8,675 5.96 1,456 2017 227,295.01 99,948 108,990 125,124 5.96 20,994 2018 289.62 110 120 178 5.96 30 2020 3.52 1 1 3 5.97 1 2021 174,287.75 13,616 14,848 164,669 5.97 27,583 3,492,590.38 2,794,213 3,046,999 550,369 93,305 COLSTRIP 3 AND COMMON - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 60-R2 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -3 1984 2,704,786.00 2,502,851 2,524,165 261,764 3.91 66,947 1985 573,677.99 529,572 534,082 56,806 3.91 14,528 1986 1,809,836.08 1,665,937 1,680,124 184,007 3.92 46,941 1987 106,373.14 97,650 98,482 11,083 3.92 2,827 1988 30,550.38 27,956 28,194 3,273 3.93 833 1989 25,386.92 23,159 23,356 2,792 3.93 710 1990 24,249.55 22,050 22,238 2,739 3.93 697 1991 35,496.64 32,154 32,428 4,134 3.94 1,049 1992 31,035.17 28,008 28,247 3,720 3.94 944 1993 16,524.27 14,853 14,979 2,041 3.94 518 1994 67,273.34 60,212 60,725 8,567 3.94 2,174 1995 26,716.70 23,794 23,997 3,522 3.95 892 1996 15,422.18 13,668 13,784 2,100 3.95 532 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-28 Attachment C J. Spanos, Avista Page 508 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 316.00 MISCELLANEOUS POWER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 3 AND COMMON - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 60-R2 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -3 1997 25,347.54 22,344 22,534 3,574 3.95 905 1998 18,480.42 16,197 16,335 2,700 3.95 684 1999 21,577.27 18,784 18,944 3,281 3.96 829 2000 31,120.32 26,909 27,138 4,916 3.96 1,241 2001 14,567.33 12,503 12,609 2,395 3.96 605 2002 19,001.39 16,175 16,313 3,259 3.96 823 2003 24,060.18 20,299 20,472 4,310 3.96 1,088 2004 21,230.66 17,724 17,875 3,993 3.97 1,006 2005 7,202.87 5,947 5,998 1,421 3.97 358 2006 42,852.42 34,949 35,247 8,891 3.97 2,240 2007 12,681.18 10,200 10,287 2,775 3.97 699 2008 19,752.04 15,641 15,774 4,570 3.97 1,151 2009 17,837.95 13,873 13,991 4,382 3.97 1,104 2010 265.32 202 204 70 3.97 18 2011 12,710.45 9,443 9,523 3,568 3.98 896 2012 40,069.18 28,939 29,185 12,086 3.98 3,037 2016 33,011.55 19,636 19,803 14,199 3.98 3,568 2018 429,225.25 205,918 207,672 234,430 3.98 58,902 2020 6.65 2 2 5 3.99 1 2021 330,910.59 37,281 37,598 303,239 3.99 76,000 6,589,238.92 5,574,830 5,622,305 1,164,611 294,747 COLSTRIP 4 - IDAHO INTERIM SURVIVOR CURVE.. IOWA 60-R2 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -4 1986 1,125,701.88 993,961 1,036,372 134,358 5.81 23,125 1987 35,948.65 31,612 32,961 4,426 5.82 760 1988 10,093.60 8,838 9,215 1,282 5.83 220 1989 12,351.05 10,764 11,223 1,622 5.84 278 1990 13,795.25 11,968 12,479 1,868 5.84 320 1991 17,897.91 15,446 16,105 2,509 5.85 429 1992 16,455.53 14,124 14,727 2,387 5.86 407 1993 13,419.23 11,449 11,938 2,018 5.87 344 1994 35,352.69 29,984 31,263 5,503 5.87 937 1995 15,928.99 13,419 13,992 2,575 5.88 438 1996 8,109.15 6,784 7,073 1,360 5.88 231 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-29 Attachment C J. Spanos, Avista Page 509 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 316.00 MISCELLANEOUS POWER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 4 - IDAHO INTERIM SURVIVOR CURVE.. IOWA 60-R2 PROBABLE RETIREMENT YEAR.. 12-2027 NET SALVAGE PERCENT.. -4 1997 13,443.56 11,160 11,636 2,345 5.89 398 1998 9,704.98 7,992 8,333 1,760 5.89 299 1999 11,232.60 9,166 9,557 2,125 5.90 360 2000 16,506.91 13,344 13,913 3,254 5.90 552 2001 7,723.91 6,177 6,441 1,592 5.91 269 2002 10,074.96 7,968 8,308 2,170 5.91 367 2003 12,757.24 9,960 10,385 2,883 5.92 487 2004 4,148.45 3,195 3,331 983 5.92 166 2005 3,819.13 2,898 3,022 950 5.92 160 2006 22,721.29 16,942 17,665 5,965 5.93 1,006 2007 6,723.82 4,920 5,130 1,863 5.93 314 2008 10,472.96 7,499 7,819 3,073 5.94 517 2009 9,457.96 6,612 6,894 2,942 5.94 495 2010 140.68 96 100 46 5.94 8 2011 6,739.37 4,441 4,630 2,378 5.94 400 2012 10,823.00 6,864 7,157 4,099 5.95 689 2016 17,414.79 8,618 8,986 9,126 5.96 1,531 2017 84,814.13 37,657 39,264 48,943 5.96 8,212 2018 289.62 111 116 185 5.96 31 2021 10,221.42 806 840 9,790 5.97 1,640 1,574,284.71 1,314,775 1,370,875 266,381 45,390 COLSTRIP 4 - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 60-R2 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -4 1986 2,123,076.99 1,973,246 1,883,227 324,773 3.92 82,850 1987 67,799.25 62,844 59,977 10,534 3.92 2,687 1988 19,036.57 17,589 16,787 3,011 3.93 766 1989 23,294.12 21,457 20,478 3,748 3.93 954 1990 26,017.87 23,888 22,798 4,260 3.93 1,084 1991 33,755.52 30,873 29,465 5,641 3.94 1,432 1992 31,035.17 28,280 26,990 5,287 3.94 1,342 1993 25,308.70 22,970 21,922 4,399 3.94 1,116 1994 66,675.27 60,256 57,507 11,835 3.94 3,004 1995 30,042.13 27,016 25,784 5,460 3.95 1,382 1996 15,293.88 13,686 13,062 2,844 3.95 720 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-30 Attachment C J. Spanos, Avista Page 510 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 316.00 MISCELLANEOUS POWER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COLSTRIP 4 - WASHINGTON INTERIM SURVIVOR CURVE.. IOWA 60-R2 PROBABLE RETIREMENT YEAR.. 12-2025 NET SALVAGE PERCENT.. -4 1997 25,354.58 22,567 21,538 4,831 3.95 1,223 1998 18,303.61 16,197 15,458 3,578 3.95 906 1999 21,184.72 18,621 17,772 4,261 3.96 1,076 2000 31,132.09 27,180 25,940 6,437 3.96 1,626 2001 14,567.33 12,624 12,048 3,102 3.96 783 2002 19,001.39 16,332 15,587 4,175 3.96 1,054 2003 24,060.18 20,496 19,561 5,462 3.96 1,379 2004 7,824.00 6,595 6,294 1,843 3.97 464 2005 7,202.87 6,005 5,731 1,760 3.97 443 2006 42,852.42 35,289 33,679 10,887 3.97 2,742 2007 12,681.18 10,299 9,829 3,359 3.97 846 2008 19,752.04 15,792 15,072 5,471 3.97 1,378 2009 17,838.04 14,008 13,369 5,183 3.97 1,306 2010 265.32 204 195 81 3.97 20 2011 12,710.45 9,535 9,100 4,119 3.98 1,035 2012 20,412.21 14,886 14,207 7,022 3.98 1,764 2016 32,844.33 19,726 18,826 15,332 3.98 3,852 2017 159,959.70 87,817 83,811 82,547 3.98 20,740 2018 546.21 265 253 315 3.98 79 2021 18,870.62 2,147 2,049 17,576 3.99 4,405 2,968,698.76 2,638,690 2,518,314 569,133 144,458 17,101,771.96 13,994,845 14,575,471 3,134,324 615,493 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 5.1 3.60 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-31 Attachment C J. Spanos, Avista Page 511 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.10 ASSET AGREEMENT - SETTLEMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LITTLE FALLS INTERIM SURVIVOR CURVE.. SQUARE PROBABLE RETIREMENT YEAR.. 12-2059 NET SALVAGE PERCENT.. 0 1995 1,700,000.00 901,000 907,486 792,514 23.50 33,724 1996 1,000,000.00 510,000 513,671 486,329 24.50 19,850 1998 302,000.00 141,940 142,962 159,038 26.50 6,001 1999 1,198,000.00 539,100 542,981 655,019 27.50 23,819 4,200,000.00 2,092,040 2,107,100 2,092,900 83,394 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 25.1 1.99 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-32 Attachment C J. Spanos, Avista Page 512 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.30 REMOVING PROPERTY OF OTHERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LITTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 100-R4 PROBABLE RETIREMENT YEAR.. 12-2059 NET SALVAGE PERCENT.. 0 1926 5,741.60 4,781 4,539 1,202 16.72 72 1927 5,348.00 4,425 4,201 1,147 17.23 67 1931 260.00 210 199 61 19.34 3 1932 2,284.00 1,828 1,736 548 19.88 28 13,633.60 11,244 10,676 2,958 170 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 100-R4 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. 0 1949 146,645.53 105,375 94,018 52,628 26.75 1,967 1950 19,045.80 13,595 12,130 6,916 27.08 255 1951 1,650.37 1,170 1,044 606 27.40 22 1952 942.98 664 592 351 27.71 13 1953 347.99 243 217 131 28.00 5 1962 2,446.88 1,607 1,434 1,013 30.16 34 171,079.55 122,654 109,434 61,645 2,296 SPOKANE UPPER FALLS INTERIM SURVIVOR CURVE.. IOWA 100-R4 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. 0 1922 41,747.26 35,559 36,559 5,189 14.82 350 1923 1,343.00 1,138 1,170 173 15.29 11 1924 776.00 654 672 104 15.77 7 1925 8,152.00 6,826 7,018 1,134 16.26 70 1926 1,929.00 1,605 1,650 279 16.76 17 1933 9,616.50 7,636 7,851 1,766 20.52 86 63,563.76 53,418 54,920 8,644 541 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-33 Attachment C J. Spanos, Avista Page 513 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.30 REMOVING PROPERTY OF OTHERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 100-R4 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. 0 1925 3,500.00 2,931 3,500 1990 6,436.75 2,912 4,247 2,190 37.95 58 9,936.75 5,843 7,747 2,190 58 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 100-R4 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. 0 1906 106.36 97 92 14 8.95 2 1907 129.18 117 111 18 9.25 2 1908 2,569.44 2,324 2,214 356 9.55 37 1909 2,750.84 2,479 2,361 390 9.87 40 1910 1,802.90 1,619 1,542 261 10.19 26 1911 1,462.48 1,309 1,247 216 10.51 21 1912 2,790.82 2,488 2,370 421 10.85 39 1913 362.92 322 307 56 11.20 5 1914 246.62 218 208 39 11.55 3 1915 59.58 52 50 10 11.92 1 1916 70.64 62 59 12 12.30 1 1917 43.56 38 36 7 12.69 1 1918 660.71 574 547 114 13.09 9 1920 26.65 23 22 5 13.93 1921 244.93 210 200 45 14.37 3 1922 130.36 111 106 25 14.82 2 1923 108.22 92 88 21 15.29 1 1924 3.29 3 3 1925 12.90 11 10 2 16.26 1926 78.00 65 62 16 16.76 1 1927 43.10 36 34 9 17.27 1 1928 136.20 112 107 30 17.79 2 1929 166.23 136 130 37 18.33 2 1930 21.00 17 16 5 18.87 1931 7.69 6 6 2 19.41 1932 2.85 2 2 1 19.97 1933 10.14 8 8 3 20.52 1934 19.77 16 15 5 21.08 1939 7.43 6 6 2 23.83 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-34 Attachment C J. Spanos, Avista Page 514 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.30 REMOVING PROPERTY OF OTHERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 100-R4 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. 0 1942 1,872.11 1,390 1,324 548 25.40 22 1943 24.98 18 17 8 25.91 1944 15.37 11 10 5 26.41 1945 145.95 106 101 45 26.91 2 1946 8.57 6 6 3 27.39 1947 13.69 10 10 4 27.86 1948 0.29 0 1949 4.89 3 3 2 28.76 1951 28.26 20 19 9 29.63 1952 2.42 2 2 1953 355.69 242 230 125 30.44 4 1954 11.83 8 8 4 30.82 1955 113.91 76 72 42 31.19 1 1957 1.29 1 1 1958 25.55 17 16 9 32.23 1962 343.42 217 207 137 33.44 4 1976 60.71 34 32 28 36.38 1 1979 1,160.48 619 589 571 36.81 16 1980 64.02 34 32 32 36.94 1 1986 2,503.59 1,212 1,154 1,350 37.61 36 1987 2,334.63 1,112 1,059 1,276 37.70 34 1991 0.43 23,166.89 17,691 16,851 6,316 320 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 100-R4 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. 0 1952 5,283,375.84 3,500,870 1,998,152 3,285,224 33.36 98,478 1953 895,974.31 587,481 335,310 560,664 33.99 16,495 1954 9,808.42 6,365 3,633 6,176 34.60 178 1955 119,053.27 76,436 43,627 75,427 35.21 2,142 1956 124,315.68 78,959 45,067 79,249 35.81 2,213 1957 50,790.90 31,912 18,214 32,577 36.40 895 1958 11,608.43 7,214 4,117 7,491 36.98 203 1959 3,693.94 2,270 1,296 2,398 37.55 64 1960 6,662.94 4,049 2,311 4,352 38.11 114 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-35 Attachment C J. Spanos, Avista Page 515 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.30 REMOVING PROPERTY OF OTHERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 100-R4 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. 0 1961 4,636.17 2,786 1,590 3,046 38.65 79 1962 859.66 511 292 568 39.18 14 1968 1,256.29 695 397 860 42.06 20 1973 12,810.28 6,653 3,797 9,013 44.04 205 1979 120,672.61 57,604 32,878 87,795 45.94 1,911 1980 1,992.62 937 535 1,458 46.21 32 1986 135,725.53 57,721 32,945 102,781 47.61 2,159 6,783,236.89 4,422,463 2,524,159 4,259,077 125,202 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 100-R4 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. 0 1959 27,118,321.26 16,403,059 8,621,153 18,497,168 39.07 473,437 1960 1,167,859.00 697,621 366,657 801,202 39.75 20,156 1961 545,597.00 321,820 169,143 376,454 40.42 9,314 1962 306,780.00 178,653 93,897 212,883 41.08 5,182 1963 30,386.38 17,464 9,179 21,208 41.74 508 1964 169,423.00 96,104 50,511 118,912 42.38 2,806 1965 67,184.00 37,605 19,765 47,419 43.01 1,103 1966 8,071.00 4,458 2,343 5,728 43.62 131 29,413,621.64 17,756,784 9,332,647 20,080,975 512,637 36,478,239.08 22,390,097 12,056,434 24,421,805 641,224 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 38.1 1.76 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-36 Attachment C J. Spanos, Avista Page 516 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.31 TWIN CREEK CHANNEL RESTORATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 100-R4 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. 0 2005 242,033.02 59,927 60,609 181,424 50.08 3,623 242,033.02 59,927 60,609 181,424 3,623 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 50.1 1.50 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-37 Attachment C J. Spanos, Avista Page 517 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.40 LAND EASEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LITTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 90-R4 PROBABLE RETIREMENT YEAR.. 12-2059 NET SALVAGE PERCENT.. 0 1910 1,963.67 1,834 1,964 1911 5.00 5 5 1924 1,637.00 1,453 1,637 1925 21.00 19 21 3,626.67 3,311 3,627 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 90-R4 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. 0 1915 94,755.26 87,049 94,755 1916 21,284.75 19,487 21,285 1920 31,938.00 28,815 31,938 1921 7,819.00 7,027 7,819 1922 6,468.00 5,789 6,468 1923 45.00 40 45 1924 1,179.00 1,046 1,179 1925 346.00 306 346 1938 120.00 98 120 1939 71.00 58 71 1949 70,732.26 53,071 65,203 5,530 22.14 250 1950 9,170.20 6,823 8,383 788 22.64 35 1951 794.63 586 720 75 23.13 3 1952 454.02 332 408 46 23.60 2 1953 207.01 150 184 23 24.07 1 1962 1,178.12 792 973 205 27.66 7 246,562.25 211,469 239,896 6,666 298 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 90-R4 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. 0 1925 979.50 865 980 979.50 865 980 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-38 Attachment C J. Spanos, Avista Page 518 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.40 LAND EASEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 90-R4 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. 0 1906 4,288.64 4,055 4,289 1907 5,208.82 4,910 5,209 1908 102,784.60 96,595 102,785 1909 110,920.16 103,908 110,920 1910 72,697.10 67,891 72,697 1911 58,970.52 54,895 58,971 1912 112,532.18 104,417 112,532 1913 14,634.08 13,535 14,603 31 6.76 5 1914 9,944.46 9,167 9,890 54 7.04 8 1915 2,402.42 2,207 2,381 21 7.32 3 1916 2,848.36 2,608 2,814 35 7.60 5 1917 1,756.44 1,602 1,728 28 7.90 4 1918 26,641.29 24,217 26,127 514 8.19 63 1920 1,074.35 969 1,045 29 8.80 3 1921 9,876.07 8,875 9,575 301 9.12 33 1922 5,256.63 4,705 5,076 181 9.45 19 1923 4,363.78 3,890 4,197 167 9.78 17 1924 132.71 118 127 5 10.13 1925 520.10 459 495 25 10.49 2 1926 3,145.00 2,765 2,983 162 10.86 15 1927 1,737.90 1,521 1,641 97 11.25 9 1928 5,491.81 4,781 5,158 334 11.65 29 1929 6,702.77 5,805 6,263 440 12.06 36 1930 847.00 729 787 60 12.49 5 1931 310.31 266 287 23 12.94 2 1932 115.14 98 106 9 13.40 1 1933 408.86 346 373 36 13.88 3 1934 797.23 670 723 74 14.37 5 1939 299.57 243 262 37 17.07 2 1942 75,487.89 59,668 64,375 11,113 18.83 590 1943 1,007.03 789 851 156 19.42 8 1944 619.63 481 519 101 20.02 5 1945 5,885.05 4,532 4,889 996 20.62 48 1946 345.43 264 285 61 21.22 3 1947 552.30 418 451 101 21.82 5 1948 11.70 9 10 2 22.41 1949 197.12 146 158 40 23.00 2 1951 1,139.73 831 897 243 24.15 10 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-39 Attachment C J. Spanos, Avista Page 519 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.40 LAND EASEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 90-R4 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. 0 1952 97.58 70 76 22 24.72 1 1953 14,342.31 10,261 11,070 3,272 25.28 129 1954 477.17 338 365 113 25.84 4 1955 4,593.09 3,224 3,478 1,115 26.38 42 1957 51.71 36 39 13 27.44 1958 1,030.45 702 757 273 27.95 10 1962 13,847.57 9,069 9,784 4,063 29.87 136 1976 2,447.99 1,376 1,485 963 34.74 28 1979 46,793.24 25,329 27,327 19,466 35.44 549 1980 2,581.20 1,379 1,488 1,093 35.66 31 1986 313,400.98 153,278 165,368 148,033 36.74 4,029 1987 94,137.78 45,288 48,860 45,278 36.89 1,227 1989 1,452,014.32 674,664 727,880 724,134 37.17 19,482 1991 17.56 8 9 9 37.42 1994 110,649.98 46,514 50,183 60,467 37.74 1,602 2,708,437.11 1,564,921 1,684,647 1,023,791 28,210 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 90-R4 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. 0 1952 285,018.42 203,295 130,866 154,153 25.78 5,980 1953 48,330.89 34,092 21,946 26,385 26.48 996 1954 529.09 369 238 292 27.18 11 1955 6,422.00 4,428 2,850 3,572 27.88 128 1956 6,705.88 4,570 2,942 3,764 28.59 132 1957 2,739.78 1,845 1,188 1,552 29.29 53 1958 626.19 417 268 358 29.99 12 1959 199.25 131 84 115 30.69 4 1960 359.41 233 150 209 31.39 7 1961 250.09 160 103 147 32.08 5 1962 46.38 29 19 28 32.77 1 1968 67.77 40 26 42 36.75 1 1973 691.02 375 241 450 39.74 11 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-40 Attachment C J. Spanos, Avista Page 520 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.40 LAND EASEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 90-R4 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. 0 1979 6,509.35 3,213 2,068 4,441 42.79 104 1980 107.48 52 33 74 43.24 2 1986 7,321.35 3,188 2,052 5,269 45.53 116 365,924.35 256,437 165,075 200,850 7,563 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 90-R4 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. 0 1959 8,209.79 5,373 5,008 3,202 31.07 103 1963 2,397.62 1,486 1,385 1,013 34.12 30 2015 70,262.50 7,202 6,712 63,550 56.83 1,118 80,869.91 14,061 13,105 67,765 1,251 3,406,399.79 2,051,064 2,107,329 1,299,072 37,322 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 34.8 1.10 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-41 Attachment C J. Spanos, Avista Page 521 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 330.41 LAND EASEMENTS - CONSERVATION - HABITAT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 90-R4 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. 0 2002 91,873.21 26,052 23,773 68,101 49.14 1,386 2005 242,033.14 60,370 55,088 186,945 49.53 3,774 2011 116,479.71 20,147 18,384 98,095 50.11 1,958 2014 390,987.38 50,727 46,289 344,699 50.31 6,852 2017 198,683.07 16,262 14,839 183,844 50.48 3,642 2018 952,151.53 61,519 56,137 896,015 50.53 17,732 1,992,208.04 235,077 214,510 1,777,698 35,344 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 90-R4 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. 0 2001 550,000.00 149,721 150,223 399,777 54.62 7,319 2012 432,234.97 62,160 62,369 369,866 56.50 6,546 982,234.97 211,881 212,592 769,643 13,865 2,974,443.01 446,958 427,102 2,547,341 49,209 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 51.8 1.65 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-42 Attachment C J. Spanos, Avista Page 522 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 MONROE STREET INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -7 1992 7,510,318.12 2,881,804 1,754,281 6,281,760 46.27 135,763 1994 94,450.97 34,641 21,087 79,975 46.44 1,722 1995 200.00 72 44 170 46.52 4 1999 24,469.44 7,834 4,769 21,413 46.84 457 2004 43,516.48 11,624 7,076 39,487 47.19 837 2006 204,147.06 49,725 30,270 188,168 47.33 3,976 2007 13,578.74 3,143 1,913 12,616 47.39 266 2009 14,696.51 3,023 1,840 13,885 47.52 292 2010 953.84 183 111 909 47.58 19 2014 20,262.07 2,717 1,654 20,026 47.81 419 2016 123,935.66 12,621 7,683 124,928 47.92 2,607 2018 192.80 13 8 198 48.03 4 2020 8,123.62 242 147 8,545 48.13 178 2021 140,141.04 1,419 864 149,087 48.18 3,094 8,198,986.35 3,009,061 1,831,747 6,941,168 149,638 LITTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2059 NET SALVAGE PERCENT.. -5 1910 351,355.14 276,526 327,048 41,874 26.48 1,581 1911 5,236.00 4,108 4,859 639 26.67 24 1913 433.04 338 400 55 27.03 2 1914 1,126.00 875 1,035 147 27.21 5 1916 8,214.00 6,345 7,504 1,120 27.57 41 1917 60.00 46 54 9 27.74 1921 188.00 143 169 28 28.43 1 1924 632.00 475 562 102 28.93 4 1925 132.00 99 117 22 29.09 1 1926 2,493.00 1,862 2,202 415 29.25 14 1927 2,290.00 1,704 2,015 389 29.41 13 1930 2,027.00 1,492 1,765 364 29.87 12 1932 182.00 133 157 34 30.17 1 1935 64.00 46 54 13 30.60 1937 753.00 539 637 153 30.88 5 1938 1,864.00 1,330 1,573 384 31.01 12 1939 753.65 535 633 159 31.15 5 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-43 Attachment C J. Spanos, Avista Page 523 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LITTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2059 NET SALVAGE PERCENT.. -5 1940 478.00 338 400 102 31.28 3 1941 149.26 105 124 33 31.41 1 1948 1,073.69 732 866 262 32.26 8 1949 946.00 641 758 235 32.37 7 1951 6,313.00 4,236 5,010 1,619 32.59 50 1952 95.91 64 76 25 32.70 1 1953 4,381.00 2,908 3,439 1,161 32.80 35 1954 2,911.00 1,922 2,273 783 32.90 24 1956 1,639.71 1,070 1,265 456 33.10 14 1957 6,435.18 4,175 4,938 1,819 33.20 55 1958 7,365.00 4,748 5,615 2,118 33.30 64 1962 3,065.00 1,926 2,278 940 33.66 28 1986 84,471.49 41,879 49,530 39,165 35.28 1,110 1988 5,581.46 2,684 3,174 2,686 35.38 76 1990 66,493.68 30,925 36,575 33,243 35.48 937 1991 92,144.27 42,106 49,799 46,953 35.52 1,322 1993 10.88 5 6 6 35.61 1995 7,161.11 3,019 3,571 3,949 35.70 111 1997 6,573.46 2,644 3,127 3,775 35.78 106 1999 2,248.12 858 1,015 1,346 35.86 38 2000 341.63 127 150 209 35.90 6 2003 3,202.14 1,076 1,273 2,090 36.01 58 2005 1,724.81 536 634 1,177 36.07 33 2006 27,394.26 8,147 9,635 19,128 36.11 530 2008 10,281.47 2,768 3,274 7,522 36.17 208 2009 293,718.35 74,631 88,266 220,138 36.21 6,079 2011 3,067.85 682 807 2,415 36.27 67 2013 4,240.91 796 941 3,512 36.33 97 2014 876,290.79 148,367 175,474 744,631 36.36 20,479 2015 350,435.61 52,530 62,127 305,830 36.39 8,404 2016 1,004,180.80 130,407 154,233 900,157 36.42 24,716 2017 323,038.73 35,205 41,637 297,554 36.44 8,166 2018 325,384.48 28,193 33,344 308,310 36.47 8,454 2019 333,099.11 21,073 24,923 324,831 36.50 8,899 2020 3,572.85 138 163 3,588 36.53 98 2021 1,234,615.70 16,464 19,472 1,276,874 36.55 34,935 5,471,929.54 964,721 1,140,980 4,604,546 126,940 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-44 Attachment C J. Spanos, Avista Page 524 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 1915 731,926.38 584,651 503,576 272,266 25.51 10,673 1916 4,034.00 3,213 2,767 1,509 25.66 59 1917 2,238.00 1,778 1,531 841 25.80 33 1918 7,942.00 6,290 5,418 3,001 25.95 116 1919 14,798.00 11,687 10,066 5,620 26.09 215 1920 11,914.00 9,382 8,081 4,548 26.23 173 1921 6,762.00 5,309 4,573 2,595 26.37 98 1922 15,297.00 11,974 10,314 5,901 26.51 223 1924 2,887.00 2,246 1,935 1,126 26.78 42 1926 9,910.19 7,662 6,599 3,905 27.05 144 1927 1,454.00 1,121 966 576 27.17 21 1928 453.00 348 300 180 27.30 7 1929 1,557.00 1,192 1,027 624 27.43 23 1930 786.00 600 517 316 27.55 11 1935 33.00 25 22 13 28.15 1936 1,113.02 832 717 463 28.26 16 1939 519.22 384 331 220 28.59 8 1940 505.06 372 320 215 28.70 7 1941 888.75 652 562 380 28.80 13 1942 1,894.23 1,383 1,191 817 28.90 28 1944 476.79 345 297 208 29.10 7 1945 1,009.00 728 627 442 29.20 15 1946 1,191.50 856 737 526 29.30 18 1947 2,700.37 1,931 1,663 1,199 29.39 41 1950 21,190.70 14,943 12,871 9,591 29.66 323 1958 6,044.84 4,090 3,523 2,885 30.31 95 1966 38,136.89 24,543 21,140 19,286 30.86 625 1969 61,745.14 38,883 33,491 31,959 31.04 1,030 1983 1,269.70 699 602 744 31.75 23 1985 33,914.87 18,201 15,677 20,273 31.84 637 1987 1,326.24 693 597 809 31.91 25 1989 2,152.79 1,091 940 1,342 31.99 42 1990 17,133.67 8,542 7,357 10,804 32.03 337 1991 9,995.77 4,901 4,221 6,374 32.06 199 1992 103,505.57 49,851 42,938 66,778 32.10 2,080 1994 6,674.88 3,094 2,665 4,410 32.17 137 1997 14,375.67 6,245 5,379 9,859 32.26 306 1998 35,177.85 14,913 12,845 24,444 32.29 757 1999 19,669.10 8,126 6,999 13,850 32.32 429 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-45 Attachment C J. Spanos, Avista Page 525 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 2002 11,983.95 4,531 3,903 8,800 32.41 272 2004 5,258.49 1,853 1,596 3,978 32.47 123 2007 6,561.94 2,035 1,753 5,203 32.55 160 2008 71,163.13 20,994 18,083 57,350 32.57 1,761 2009 1,935.35 540 465 1,586 32.60 49 2010 30,228.20 7,931 6,831 25,211 32.62 773 2012 150,973.82 34,232 29,485 130,547 32.67 3,996 2013 162,494.42 33,763 29,081 143,163 32.69 4,379 2014 1,582,166.80 296,611 255,479 1,421,618 32.72 43,448 2015 63,914.46 10,640 9,165 58,585 32.74 1,789 2016 438,083.29 63,293 54,516 409,852 32.76 12,511 2017 47,029.17 5,709 4,917 44,934 32.78 1,371 2018 3,470,068.67 337,150 290,396 3,387,876 32.80 103,289 2019 392,239.00 27,882 24,016 391,758 32.83 11,933 2020 31,297.59 1,375 1,184 31,991 32.85 974 2021 26,250.54 392 338 27,488 32.87 836 7,686,252.01 1,702,707 1,466,588 6,680,839 206,700 SPOKANE UPPER FALLS INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -6 1922 334,364.31 254,304 336,342 18,084 29.08 622 1923 824.00 624 825 48 29.26 2 1924 341.00 258 341 20 29.43 1 1930 953.00 704 931 79 30.42 3 1940 185.00 131 173 23 31.90 1 1942 192.00 135 179 25 32.17 1 1945 626.62 434 574 90 32.56 3 1950 855.00 577 763 143 33.16 4 1951 142.00 95 126 25 33.28 1 1952 279.00 186 246 50 33.39 1 1953 2,176.17 1,446 1,912 394 33.50 12 1954 920.00 608 804 171 33.61 5 1957 514.00 334 442 103 33.92 3 1966 2,906.35 1,773 2,345 736 34.76 21 1982 10,196.78 5,317 7,032 3,776 35.90 105 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-46 Attachment C J. Spanos, Avista Page 526 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SPOKANE UPPER FALLS INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -6 1994 1,875.33 803 1,062 926 36.52 25 1998 14,368.94 5,596 7,401 7,830 36.69 213 1999 19,085.85 7,233 9,566 10,665 36.73 290 2002 31,174.13 10,767 14,240 18,804 36.85 510 2008 46,456.93 12,373 16,365 32,880 37.07 887 2009 44,341.57 11,151 14,748 32,254 37.10 869 2012 348,085.01 70,650 93,442 275,529 37.20 7,407 2014 25,792.13 4,314 5,706 21,634 37.26 581 2016 66,347.05 8,499 11,241 59,087 37.32 1,583 2019 60,943.49 3,803 5,030 59,570 37.41 1,592 2020 46,747.42 1,786 2,362 47,190 37.44 1,260 2021 53,886.53 693 917 56,203 37.47 1,500 1,114,579.61 404,594 535,115 646,339 17,502 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1908 126,339.99 98,660 61,006 70,388 26.49 2,657 1925 1,223.96 904 559 714 29.60 24 1927 12,989.00 9,520 5,887 7,622 29.93 255 1928 19,335.78 14,119 8,730 11,379 30.09 378 1929 27,981.00 20,353 12,585 16,515 30.26 546 1930 8,044.00 5,829 3,604 4,761 30.42 157 1931 15.00 11 7 9 30.57 1938 237.00 166 103 144 31.62 5 1940 126.00 88 54 77 31.90 2 1941 179.17 124 77 110 32.03 3 1947 292.03 197 122 182 32.80 6 1953 1,033.84 674 417 658 33.50 20 1955 400.25 258 160 257 33.71 8 1956 701.00 449 278 451 33.82 13 1961 9,818.34 6,092 3,767 6,444 34.31 188 1963 80.86 49 30 54 34.49 2 1966 144.00 86 53 97 34.76 3 1967 3,350.00 1,990 1,231 2,253 34.84 65 1971 2,905.00 1,669 1,032 1,989 35.16 57 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-47 Attachment C J. Spanos, Avista Page 527 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1972 3,476.58 1,980 1,224 2,391 35.23 68 1980 411.42 216 134 294 35.77 8 1981 9,922.05 5,139 3,178 7,141 35.84 199 1984 26,115.12 13,014 8,047 19,113 36.01 531 1985 723.40 355 220 533 36.07 15 1986 21,186.25 10,262 6,345 15,688 36.12 434 1987 114.96 55 34 86 36.18 2 1994 2,577,412.48 1,083,060 669,702 2,010,807 36.52 55,060 1995 226,189.23 93,013 57,514 177,723 36.56 4,861 1997 1,627.42 638 395 1,298 36.65 35 1998 8,156.07 3,116 1,927 6,556 36.69 179 1999 5,309.51 1,974 1,221 4,301 36.73 117 2000 9,543.30 3,448 2,132 7,793 36.77 212 2001 1,425.08 499 309 1,174 36.81 32 2005 8,887.43 2,686 1,661 7,582 36.96 205 2013 368,816.25 67,144 41,518 342,051 37.23 9,188 2014 2,440,050.62 400,391 247,579 2,290,074 37.26 61,462 2015 1,926,956.79 280,144 173,225 1,830,810 37.29 49,097 2016 6,815,497.13 856,599 529,672 6,558,445 37.32 175,735 2017 4,933,773.91 519,783 321,404 4,809,721 37.35 128,774 2018 423,778.50 35,554 21,985 418,745 37.38 11,202 2019 15,943.96 976 604 15,978 37.41 427 2020 7,633.33 286 177 7,762 37.44 207 2021 912.51 12 7 942 37.47 25 20,049,059.52 3,541,582 2,189,911 18,661,111 502,464 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1906 100,200.31 78,718 90,812 13,396 26.10 513 1907 3,539.46 2,772 3,198 483 26.30 18 1908 2,812.29 2,196 2,533 391 26.49 15 1909 163.00 127 147 23 26.69 1 1910 29,239.00 22,692 26,178 4,230 26.88 157 1911 8,493.00 6,571 7,581 1,252 27.07 46 1912 254.00 196 226 38 27.26 1 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-48 Attachment C J. Spanos, Avista Page 528 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1913 1,627.00 1,251 1,443 249 27.45 9 1914 713.00 546 630 112 27.64 4 1921 237.00 177 204 42 28.91 1 1922 359.00 268 309 64 29.08 2 1923 1,424.00 1,059 1,222 259 29.26 9 1925 143.00 106 122 26 29.60 1 1926 7,044.00 5,182 5,978 1,348 29.76 45 1927 2,171.00 1,591 1,835 422 29.93 14 1928 61.00 45 52 12 30.09 1929 24,275.00 17,657 20,370 4,876 30.26 161 1932 75.00 54 62 16 30.73 1 1936 78.00 55 63 18 31.33 1 1939 127.00 89 103 29 31.76 1 1940 328.92 229 264 78 31.90 2 1941 160.34 111 128 39 32.03 1 1942 11.00 8 9 2 32.17 1943 653.00 448 517 162 32.30 5 1945 2,507.00 1,703 1,965 643 32.56 20 1946 2,671.50 1,806 2,083 695 32.68 21 1947 1,298.24 874 1,008 342 32.80 10 1948 1,334.77 894 1,031 357 32.92 11 1949 1,189.68 792 914 324 33.04 10 1951 2,121.49 1,398 1,613 594 33.28 18 1952 564.44 370 427 160 33.39 5 1953 76.00 50 58 21 33.50 1 1954 22.00 14 16 7 33.61 1955 2,332.00 1,503 1,734 691 33.71 20 1956 756.00 484 558 228 33.82 7 1957 178.00 113 130 55 33.92 2 1958 819.15 518 598 254 34.02 7 1959 1,406.00 884 1,020 442 34.12 13 1963 998.00 611 705 333 34.49 10 1964 29,385.00 17,856 20,599 9,961 34.58 288 1965 1,638.00 988 1,140 564 34.67 16 1966 682.72 409 472 238 34.76 7 1968 1,307.00 770 888 471 34.92 13 1980 125.13 66 76 54 35.77 2 1981 1,894.68 981 1,132 839 35.84 23 1982 31,717.08 16,227 18,720 14,266 35.90 397 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-49 Attachment C J. Spanos, Avista Page 529 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1984 18,588.50 9,263 10,686 8,646 36.01 240 1985 18,140.23 8,914 10,284 8,582 36.07 238 1986 231.93 112 129 112 36.12 3 1988 12,367.93 5,808 6,700 6,162 36.23 170 1989 22,560.55 10,423 12,024 11,439 36.28 315 1990 2,287.23 1,039 1,199 1,180 36.33 32 1991 1,312.50 585 675 690 36.38 19 1992 11,114.19 4,865 5,612 5,946 36.42 163 1993 13,497.07 5,792 6,682 7,355 36.47 202 1994 3,107.28 1,306 1,507 1,725 36.52 47 1998 129,973.74 49,664 57,294 77,878 36.69 2,123 1999 32,441.94 12,063 13,916 19,823 36.73 540 2004 1,619.10 510 588 1,096 36.92 30 2006 81,785.53 23,638 27,270 57,787 37.00 1,562 2007 220,514.81 60,772 70,109 159,227 37.03 4,300 2008 297,987.67 77,867 89,830 220,077 37.07 5,937 2009 12,328.51 3,042 3,509 9,312 37.10 251 2013 111,058.77 20,218 23,324 92,177 37.23 2,476 2014 55,146.73 9,049 10,439 46,913 37.26 1,259 2015 4,316.87 628 724 3,765 37.29 101 2016 1,643,728.12 206,590 238,330 1,471,147 37.32 39,420 2017 177,264.67 18,675 21,544 162,811 37.35 4,359 2018 77,988.95 6,543 7,548 73,560 37.38 1,968 2019 6,826.48 418 482 6,617 37.41 177 2020 249,222.56 9,344 10,780 248,412 37.44 6,635 2021 3,277,042.10 41,341 47,693 3,360,431 37.47 89,683 6,751,666.16 779,928 899,754 6,121,978 164,159 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 1952 5,998,653.03 3,899,048 3,602,049 3,176,429 40.89 77,682 1953 876,812.58 565,974 522,863 467,936 41.08 11,391 1955 437.80 279 258 237 41.44 6 1956 499.92 316 292 273 41.62 7 1957 4,670.00 2,928 2,705 2,572 41.80 62 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-50 Attachment C J. Spanos, Avista Page 530 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 1969 1,173.01 663 612 713 43.69 16 1970 7,790.00 4,361 4,029 4,774 43.83 109 1971 7,941.43 4,400 4,065 4,909 43.97 112 1972 3,210.00 1,760 1,626 2,001 44.10 45 1981 4,749.00 2,331 2,153 3,213 45.20 71 1983 18,010.60 8,586 7,932 12,420 45.41 274 1984 165,494.62 77,700 71,781 115,228 45.51 2,532 1985 10,700.38 4,943 4,566 7,525 45.62 165 1986 244.02 111 103 173 45.72 4 1987 7,986.76 3,568 3,296 5,729 45.81 125 1989 42,610.77 18,352 16,954 31,196 46.00 678 1991 206,498.04 85,455 78,946 154,397 46.19 3,343 1992 214,186.39 86,795 80,184 161,847 46.27 3,498 1993 38,273.42 15,167 14,012 29,237 46.36 631 1995 22,254.07 8,411 7,770 17,377 46.52 374 1996 2,711.18 998 922 2,142 46.61 46 1997 39,433.38 14,141 13,064 31,496 46.68 675 1999 137,169.01 46,379 42,846 112,155 46.84 2,394 2000 118,554.70 38,836 35,878 98,089 46.91 2,091 2001 64,510.48 20,435 18,878 54,018 46.98 1,150 2003 46,834.81 13,769 12,720 40,203 47.12 853 2004 115,843.91 32,679 30,190 100,714 47.19 2,134 2005 12,313.24 3,323 3,070 10,844 47.26 229 2006 37,486.23 9,643 8,908 33,451 47.33 707 2007 28,597.16 6,990 6,458 25,857 47.39 546 2009 29,129.21 6,328 5,846 27,070 47.52 570 2010 580,761.64 117,904 108,923 547,338 47.58 11,504 2011 24,182.09 4,555 4,208 23,118 47.64 485 2013 1,352,670.16 213,442 197,184 1,331,334 47.75 27,881 2014 26,377.30 3,735 3,450 26,356 47.81 551 2015 413,820.69 51,620 47,688 419,929 47.87 8,772 2016 1,058,776.35 113,863 105,190 1,091,227 47.92 22,772 2017 2,993,553.20 267,505 247,129 3,135,587 47.98 65,352 2018 1,017,731.48 72,050 66,562 1,083,475 48.03 22,558 2019 6,659,013.75 343,502 317,337 7,207,349 48.08 149,903 2020 180,420.40 5,682 5,249 198,626 48.13 4,127 2021 862,782.49 9,223 8,520 966,424 48.18 20,059 23,434,868.70 6,187,750 5,716,415 20,764,986 446,484 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-51 Attachment C J. Spanos, Avista Page 531 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 1959 6,197,842.76 3,901,633 3,205,921 4,293,468 46.18 92,972 1960 250,457.46 156,318 128,444 174,609 46.39 3,764 1961 5,133.03 3,175 2,609 3,602 46.61 77 1962 20,854.55 12,782 10,503 14,731 46.82 315 1965 3,207.21 1,910 1,569 2,311 47.43 49 1966 4,775.16 2,817 2,315 3,463 47.62 73 1968 367.70 212 174 271 48.01 6 1970 2,295.75 1,298 1,067 1,711 48.38 35 1971 372.90 209 172 279 48.56 6 1973 1,097.39 600 493 835 48.91 17 1977 1,701,943.79 884,245 726,573 1,332,779 49.57 26,887 1978 362,980.42 186,026 152,855 286,351 49.73 5,758 1980 768.01 383 315 615 50.03 12 1983 3,784.84 1,801 1,480 3,100 50.47 61 1985 15,044.70 6,925 5,690 12,514 50.74 247 1986 767,053.21 346,779 284,944 643,191 50.88 12,641 1987 5,148.85 2,286 1,878 4,352 51.01 85 1988 14,450.80 6,295 5,173 12,313 51.14 241 1989 19,436.91 8,303 6,822 16,696 51.26 326 1990 4,932.08 2,063 1,695 4,273 51.39 83 1991 137,177.47 56,174 46,157 119,827 51.51 2,326 1992 81,589.33 32,686 26,858 71,865 51.62 1,392 1993 31,804.21 12,445 10,226 28,257 51.74 546 1995 93,989.82 34,989 28,750 84,978 51.96 1,635 1996 14,153.04 5,129 4,214 12,911 52.07 248 1997 265,922.66 93,676 76,972 244,794 52.18 4,691 1998 143,677.23 49,140 40,378 133,472 52.28 2,553 1999 176,353.93 58,449 48,027 165,361 52.38 3,157 2000 8,388.81 2,690 2,210 7,940 52.48 151 2001 5,128.92 1,588 1,305 4,901 52.58 93 2002 4,075.68 1,215 998 3,933 52.68 75 2003 83.76 24 20 82 52.77 2 2004 56,777.43 15,583 12,804 55,896 52.87 1,057 2005 29,010.35 7,606 6,250 28,853 52.96 545 2006 152,228.54 38,029 31,248 152,949 53.04 2,884 2007 696,234.05 164,891 135,489 706,954 53.13 13,306 2008 8,317.99 1,859 1,528 8,537 53.22 160 2009 193,050.15 40,533 33,305 200,285 53.30 3,758 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-52 Attachment C J. Spanos, Avista Page 532 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 110-R1.5 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2010 792,771.86 155,284 127,595 831,659 53.38 15,580 2011 827,975.25 150,067 123,308 878,542 53.47 16,431 2012 86,624.05 14,433 11,859 92,956 53.54 1,736 2013 168,519.90 25,489 20,944 182,965 53.62 3,412 2014 1,347,044.43 182,486 149,946 1,479,977 53.70 27,560 2015 1,726,747.78 205,970 169,243 1,920,122 53.77 35,710 2016 547,708.76 56,100 46,097 616,631 53.85 11,451 2017 161,911.87 13,781 11,324 184,590 53.92 3,423 2018 2,022,254.85 136,098 111,830 2,335,098 53.99 43,251 2019 1,513,634.28 74,121 60,904 1,770,593 54.06 32,752 2020 770,088.68 22,997 18,896 912,911 54.13 16,865 2021 42,567.25 434 357 51,150 54.20 944 21,487,759.85 7,180,026 5,899,734 20,100,455 391,349 94,195,101.74 23,770,369 19,680,245 84,521,422 2,005,236 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 42.2 2.13 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-53 Attachment C J. Spanos, Avista Page 533 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.10 STRUCTURES AND IMPROVEMENTS - FISH AND WILDLIFE CONSERVATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 55-S2.5 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 1993 64,872.23 36,119 64,871 3,893 24.62 158 2021 1,506.10 24 43 1,553 33.38 47 66,378.33 36,143 64,914 5,447 205 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 55-S2.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 2000 2,664.78 1,141 2,565 207 30.10 7 2021 3,516.31 48 108 3,549 37.75 94 6,181.09 1,189 2,673 3,756 101 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 55-S2.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 1994 1,140.98 621 802 487 28.33 17 2003 9,469.03 3,647 4,712 5,988 35.32 170 2010 12,927.68 3,231 4,175 10,434 40.39 258 2012 4,846.30 1,015 1,311 4,165 41.69 100 2015 3,266.08 480 620 3,071 43.47 71 31,650.07 8,994 11,620 24,144 616 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 55-S2.5 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 1994 1,448.95 839 504 1,249 28.62 44 2001 6,257.99 2,789 1,677 5,895 34.50 171 2006 89,764.55 30,838 18,543 90,072 38.79 2,322 2013 644,322.07 124,982 75,152 704,477 44.47 15,842 2014 155,921.29 26,809 16,120 172,544 45.22 3,816 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-54 Attachment C J. Spanos, Avista Page 534 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.10 STRUCTURES AND IMPROVEMENTS - FISH AND WILDLIFE CONSERVATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 55-S2.5 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2017 28,063.21 2,946 1,771 32,185 47.36 680 2020 37,187.00 1,329 799 44,197 49.30 896 2021 127,156.01 1,526 918 152,941 49.90 3,065 1,090,121.07 192,058 115,486 1,203,561 26,836 1,194,330.56 238,384 194,693 1,236,908 27,758 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 44.6 2.32 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-55 Attachment C J. Spanos, Avista Page 535 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.20 STRUCTURES AND IMPROVEMENTS - RECREATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 MONROE STREET INTERIM SURVIVOR CURVE.. IOWA 50-R2.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -7 1975 7,680.00 5,973 4,706 3,511 13.66 257 1992 412,574.09 224,749 177,090 264,364 24.52 10,782 1993 55,868.81 29,542 23,278 36,502 25.26 1,445 1994 31,578.47 16,197 12,762 21,027 25.99 809 2014 3,529,323.57 561,660 442,558 3,333,818 40.18 82,972 4,037,024.94 838,121 660,395 3,659,222 96,265 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 50-R2.5 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 1993 34,452.43 18,819 22,000 14,520 23.41 620 1994 24,243.94 12,908 15,090 10,609 23.92 444 2004 6,495.09 2,498 2,920 3,965 28.22 141 2006 57,517.50 20,224 23,643 37,326 28.89 1,292 2007 82,524.79 27,601 32,266 55,210 29.20 1,891 2012 66,777.77 16,065 18,781 52,004 30.52 1,704 2013 250,211.63 54,986 64,280 200,944 30.74 6,537 2014 257,679.55 51,083 59,718 213,423 30.95 6,896 2015 652,299.53 114,467 133,816 557,622 31.15 17,901 2018 202,584.43 20,591 24,072 190,668 31.68 6,019 2020 12,694.92 580 678 12,779 31.99 399 2021 73,200.33 1,142 1,335 76,257 32.13 2,373 1,720,681.91 340,964 398,598 1,425,325 46,217 SPOKANE UPPER FALLS INTERIM SURVIVOR CURVE.. IOWA 50-R2.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -6 1974 5,979.70 4,673 6,401 62 - 5,979.70 4,673 6,401 62 - _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-56 Attachment C J. Spanos, Avista Page 536 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.20 STRUCTURES AND IMPROVEMENTS - RECREATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 50-R2.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 2014 176,785.92 31,361 48,774 135,083 34.38 3,929 2015 110,074.63 17,247 26,823 87,654 34.67 2,528 2019 83,891.11 5,477 8,518 78,729 35.68 2,207 370,751.66 54,085 84,116 301,466 8,664 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 50-R2.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1990 3,716.97 2,106 1,817 2,049 22.54 91 2006 198,854.47 64,499 55,651 151,158 31.44 4,808 2012 43,537.76 9,457 8,160 37,120 33.75 1,100 2014 32,396.62 5,747 4,959 28,734 34.38 836 2015 361,091.33 56,578 48,816 326,719 34.67 9,424 2016 2,761.44 373 322 2,550 34.94 73 2017 180,519.52 20,353 17,561 170,179 35.20 4,835 2018 48,978.25 4,374 3,774 47,163 35.45 1,330 2019 10,913.58 713 615 10,735 35.68 301 2020 13,400.64 534 461 13,476 35.90 375 2021 5,008.16 68 59 5,150 36.10 143 901,178.74 164,802 142,194 795,032 23,316 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 50-R2.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 1993 16,949.60 9,465 12,520 6,633 25.26 263 1994 786.81 426 563 326 25.99 13 1995 5,000.00 2,622 3,468 2,182 26.74 82 2000 15,100.89 6,593 8,721 8,343 30.48 274 2001 294,941.72 123,395 163,221 170,063 31.23 5,446 2002 8,994.62 3,599 4,761 5,403 31.98 169 2004 204,365.84 74,277 98,250 132,683 33.45 3,967 2006 23,947.47 7,803 10,321 16,739 34.90 480 2007 64,984.82 19,947 26,385 47,048 35.61 1,321 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-57 Attachment C J. Spanos, Avista Page 537 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.20 STRUCTURES AND IMPROVEMENTS - RECREATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 50-R2.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 2008 11,275.05 3,243 4,290 8,451 36.31 233 2009 71,020.92 19,042 25,188 55,066 37.00 1,488 2011 41,933.76 9,603 12,702 34,683 38.32 905 2012 169,622.14 35,415 46,845 144,828 38.96 3,717 2013 9,829.48 1,854 2,452 8,655 39.58 219 2015 8,357.12 1,229 1,626 7,818 40.76 192 2016 198,015.48 24,877 32,906 190,851 41.33 4,618 2017 103,696.27 10,774 14,251 102,925 41.87 2,458 2018 45,127.67 3,683 4,872 46,123 42.39 1,088 2019 30,213.22 1,788 2,365 31,776 42.88 741 2020 37,273.43 1,336 1,767 40,352 43.36 931 2021 992,605.95 12,159 16,083 1,105,561 43.81 25,235 2,354,042.26 373,130 493,559 2,166,509 53,840 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 50-R2.5 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 1990 7,180.92 4,673 4,848 3,841 23.11 166 1992 10,530.55 6,478 6,721 6,021 24.58 245 1993 5,983.25 3,574 3,708 3,532 25.32 139 1994 17,352.07 10,042 10,418 10,578 26.08 406 1995 16,535.20 9,265 9,612 10,396 26.84 387 2000 52,789.66 24,519 25,437 38,438 30.77 1,249 2002 38,409.96 16,312 16,923 29,553 32.38 913 2003 4,027.16 1,630 1,691 3,182 33.18 96 2004 299,668.32 115,212 119,527 243,072 33.99 7,151 2006 206,696.01 71,012 73,672 176,431 35.61 4,955 2007 180,618.34 58,300 60,484 158,065 36.42 4,340 2009 77,021.38 21,628 22,438 70,758 38.02 1,861 2010 77,628.62 20,166 20,921 73,009 38.81 1,881 2011 6,778.08 1,615 1,675 6,526 39.60 165 2012 44,775.09 9,705 10,068 44,109 40.37 1,093 2013 3,545.23 691 717 3,573 41.14 87 2014 65,636.65 11,371 11,797 67,623 41.89 1,614 2015 30,401.58 4,592 4,764 32,022 42.63 751 2016 222,038.84 28,522 29,590 239,077 43.36 5,514 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-58 Attachment C J. Spanos, Avista Page 538 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.20 STRUCTURES AND IMPROVEMENTS - RECREATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 50-R2.5 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2017 29,790.80 3,157 3,275 32,772 44.07 744 2018 458,353.87 38,079 39,505 515,103 44.76 11,508 2019 339,830.66 20,305 21,065 390,130 45.43 8,587 2020 64,477.28 2,332 2,419 75,598 46.09 1,640 2021 72,239.99 889 922 86,488 46.72 1,851 2,332,309.51 484,069 502,199 2,319,895 57,343 11,721,968.72 2,259,844 2,287,462 10,667,387 285,645 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 37.3 2.44 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-59 Attachment C J. Spanos, Avista Page 539 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 331.26 STRUCTURES AND IMPROVEMENTS - RECREATION INFORMATION AND EDUCATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 50-R3 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 2004 24,242.30 9,162 16,805 10,588 33.09 320 2018 4,172.82 348 638 4,077 43.20 94 2020 9,495.79 345 633 10,097 44.28 228 37,910.91 9,855 18,077 24,763 642 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 50-R3 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2004 11,358.62 4,571 5,990 7,754 33.35 233 2020 2,246.94 83 109 2,610 46.84 56 13,605.56 4,654 6,099 10,364 289 51,516.47 14,509 24,175 35,127 931 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 37.7 1.81 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-60 Attachment C J. Spanos, Avista Page 540 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.00 RESERVOIRS, DAMS AND WATERWAYS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 MONROE STREET INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -7 1972 1,527,619.08 772,637 435,752 1,198,801 43.93 27,289 1973 955,021.89 477,889 269,520 752,354 44.03 17,087 1974 20,646.77 10,219 5,763 16,329 44.13 370 1975 509.80 249 140 405 44.23 9 1992 2,497,418.44 936,112 527,948 2,144,289 45.66 46,962 1994 240,802.88 86,324 48,685 208,974 45.79 4,564 1995 2,739,018.41 958,267 540,443 2,390,306 45.86 52,122 1997 43,306.50 14,378 8,109 38,229 45.99 831 1998 6,833.48 2,206 1,244 6,068 46.05 132 1999 946.12 296 167 845 46.12 18 2010 9,557.31 1,801 1,016 9,211 46.74 197 2011 1,930,338.85 337,848 190,539 1,874,923 46.79 40,071 9,972,019.53 3,598,226 2,029,327 8,640,734 189,652 LITTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2059 NET SALVAGE PERCENT.. -5 1910 611,600.16 467,860 642,180 1911 2,825.00 2,155 2,966 1912 3,289.00 2,502 3,453 1913 423.06 321 444 1914 259.00 196 272 1916 8,598.73 6,466 9,029 1920 952.03 707 1,000 1921 109.00 81 114 1923 330.00 243 347 1925 2,383.00 1,743 2,502 1926 890.00 649 935 1927 859.00 624 902 1934 260.00 184 273 1942 499.00 342 524 1943 450.00 307 473 1944 249.00 169 261 1945 393.00 266 412 1 32.29 1946 3,015.00 2,032 3,144 22 32.38 1 1952 176.00 115 178 7 32.89 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-61 Attachment C J. Spanos, Avista Page 541 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.00 RESERVOIRS, DAMS AND WATERWAYS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LITTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2059 NET SALVAGE PERCENT.. -5 1954 663.00 429 664 32 33.05 1 1955 889.00 572 885 48 33.13 1 1956 13,912.00 8,904 13,777 830 33.21 25 1957 4,697.00 2,989 4,625 307 33.28 9 1958 2,795.00 1,768 2,736 199 33.35 6 1960 410.00 256 396 34 33.50 1 1962 8,912.00 5,496 8,504 854 33.64 25 1963 17,387.00 10,650 16,479 1,777 33.70 53 1966 1,479.00 887 1,372 180 33.90 5 1970 17,295.00 10,048 15,547 2,612 34.14 77 1973 5,689.33 3,220 4,982 991 34.31 29 1974 758.50 425 658 139 34.37 4 1977 7,577.12 4,125 6,383 1,573 34.52 46 1984 920.27 461 713 253 34.85 7 1987 16,462.87 7,906 12,233 5,053 34.98 144 1988 24,486.96 11,578 17,915 7,796 35.02 223 1989 17,631.63 8,202 12,691 5,822 35.06 166 1994 61,907.68 26,243 40,606 24,397 35.24 692 1995 2,253.91 935 1,447 920 35.27 26 1997 410,414.98 162,484 251,415 179,521 35.34 5,080 1999 1,657,476.43 622,732 963,566 776,784 35.41 21,937 2000 762,281.39 278,289 430,602 369,793 35.44 10,434 2001 1,182,979.51 418,920 648,204 593,925 35.47 16,744 2005 35,540.52 10,882 16,838 20,480 35.59 575 2015 6,941.38 1,028 1,591 5,698 35.87 159 2017 152,635.39 16,342 25,286 134,981 35.93 3,757 2018 53,954.35 4,617 7,144 49,508 35.95 1,377 2019 1,273,641.26 79,691 123,308 1,214,016 35.98 33,741 6,379,552.46 2,187,041 3,299,976 3,398,554 95,345 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 1915 2,576,037.01 2,010,568 2,730,599 1916 3,271.00 2,546 3,467 1917 1,530.00 1,188 1,622 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-62 Attachment C J. Spanos, Avista Page 542 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.00 RESERVOIRS, DAMS AND WATERWAYS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 1918 64,061.00 49,610 67,905 1919 93,808.00 72,446 99,436 1920 23,359.00 17,992 24,761 1921 15,521.00 11,922 16,452 1922 3,110.00 2,382 3,297 1923 62,619.00 47,830 66,376 1924 12,500.00 9,520 13,250 1925 2,785.00 2,115 2,952 1926 1,997.00 1,512 2,117 1929 243.00 182 258 1930 58,587.00 43,814 62,102 1934 3,256.00 2,403 3,451 1940 659.00 476 699 1946 183.00 129 194 1949 135,867.42 94,608 142,250 1,770 29.76 59 1950 6,787.32 4,704 7,073 122 29.83 4 1951 26,173.19 18,055 27,147 597 29.90 20 1952 8,384.51 5,757 8,656 232 29.96 8 1955 1,231.16 833 1,252 53 30.15 2 1960 5,951.45 3,915 5,886 422 30.45 14 1961 25,831.00 16,896 25,404 1,977 30.50 65 1962 18,134.00 11,788 17,724 1,498 30.56 49 1963 19,741.00 12,753 19,175 1,750 30.61 57 1964 71.06 46 69 6 30.66 1969 2,353.00 1,458 2,192 302 30.91 10 1971 7,096.11 4,331 6,512 1,010 31.00 33 1987 413,923.95 212,952 320,188 118,572 31.61 3,751 1988 385,288.23 195,279 293,615 114,790 31.65 3,627 1989 671,078.82 335,000 503,695 207,648 31.68 6,555 1990 1,917,672.47 942,070 1,416,466 616,267 31.71 19,434 1992 2,090,902.34 992,795 1,492,734 723,622 31.76 22,784 1993 63,488.82 29,586 44,485 22,814 31.79 718 1994 2,168,656.90 991,186 1,490,315 808,461 31.82 25,407 1995 634,895.44 284,257 427,400 245,590 31.85 7,711 1996 25,228.73 11,055 16,622 10,121 31.87 318 1997 586,378.29 251,086 377,525 244,036 31.90 7,650 1999 1,999,403.05 814,409 1,224,519 894,848 31.95 28,008 2000 1,407,141.49 557,370 838,043 653,527 31.98 20,435 2001 59,796.76 23,012 34,600 28,784 32.00 900 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-63 Attachment C J. Spanos, Avista Page 543 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.00 RESERVOIRS, DAMS AND WATERWAYS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 2002 350.72 131 197 175 32.02 5 2004 131,851.04 45,856 68,948 70,815 32.07 2,208 2011 34,640.08 8,380 12,600 24,119 32.23 748 2013 277,129.01 56,754 85,333 208,423 32.28 6,457 2014 373,634.16 69,214 104,068 291,984 32.30 9,040 2015 698,947.32 115,022 172,943 567,941 32.32 17,572 2016 16,452,667.07 2,351,412 3,535,507 13,904,321 32.34 429,942 2017 1,012,534.38 121,475 182,646 890,641 32.36 27,523 2018 1,350,265.40 129,459 194,650 1,236,631 32.38 38,191 2019 383,827.03 27,076 40,711 366,146 32.40 11,301 2021 1,374,026.24 20,361 30,614 1,425,854 32.45 43,940 37,694,874.97 11,036,976 16,270,701 23,685,866 734,546 SPOKANE UPPER FALLS INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -6 1922 476,615.72 352,916 430,780 74,433 30.41 2,448 1923 29,805.45 22,001 26,855 4,739 30.53 155 1924 2,210.00 1,626 1,985 358 30.66 12 1925 425.00 312 381 70 30.79 2 1926 3,128.00 2,286 2,790 525 30.91 17 1927 342.00 249 304 59 31.03 2 1928 40.00 29 35 7 31.15 1930 927.00 668 815 167 31.39 5 1932 60.00 43 52 11 31.62 1936 430.00 303 370 86 32.06 3 1940 95.00 66 81 20 32.48 1 1943 44.00 30 37 10 32.78 1944 521.00 355 433 119 32.88 4 1947 106.66 72 88 25 33.16 1 1948 2,375.37 1,587 1,937 581 33.25 17 1949 25.02 17 21 6 33.34 1952 690.58 452 552 180 33.60 5 1953 875.90 570 696 233 33.69 7 1955 611.45 394 481 167 33.85 5 1957 5,424.43 3,451 4,212 1,538 34.01 45 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-64 Attachment C J. Spanos, Avista Page 544 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.00 RESERVOIRS, DAMS AND WATERWAYS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SPOKANE UPPER FALLS INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -6 1958 194.00 123 150 56 34.09 2 1960 1,050.00 656 801 312 34.24 9 1962 206.00 127 155 63 34.39 2 1969 5,000.00 2,923 3,568 1,732 34.86 50 1973 9,150.98 5,167 6,307 3,393 35.10 97 1976 8,267.46 4,533 5,533 3,230 35.27 92 1989 10,046.06 4,650 5,676 4,973 35.89 139 1990 35,855.73 16,314 19,913 18,094 35.93 504 1993 13,881.71 5,968 7,285 7,430 36.05 206 1994 354.19 149 182 194 36.08 5 1995 50,002.76 20,609 25,156 27,847 36.12 771 1998 1,081,101.16 414,107 505,471 640,496 36.23 17,679 1999 225,620.73 84,138 102,701 136,457 36.26 3,763 2000 1,072.35 389 475 662 36.29 18 2003 368,311.75 120,828 147,486 242,924 36.39 6,676 2004 82.42 26 32 56 36.42 2 2005 4,689,300.37 1,422,254 1,736,045 3,234,614 36.45 88,741 2011 547,977.84 118,593 144,758 436,098 36.64 11,902 2015 31,886.61 4,655 5,682 28,118 36.75 765 2019 124,458.69 7,685 9,381 122,546 36.86 3,325 7,728,573.39 2,621,321 3,199,661 4,992,627 137,477 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1908 665,042.03 504,015 27,928 - 719,572 28.43 25,310 1921 1,261.87 920 51 - 1,363 30.28 45 1926 565.00 405 22 - 610 30.91 20 1927 617.00 441 24 - 666 31.03 21 1928 25,607.82 18,234 1,010 - 27,643 31.15 887 1932 279.00 196 11 - 301 31.62 10 1948 441.66 289 16 - 475 33.25 14 1949 467.00 305 17 - 503 33.34 15 1953 77.17 49 3 - 83 33.69 2 1954 443.94 282 16 - 477 33.77 14 1972 5,563.00 3,110 172 - 5,958 35.04 170 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-65 Attachment C J. Spanos, Avista Page 545 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.00 RESERVOIRS, DAMS AND WATERWAYS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1973 549.10 304 17 - 588 35.10 17 1978 30,650.97 16,145 895 - 32,772 35.38 926 1991 248,715.55 109,055 6,043 - 264,707 35.97 7,359 1995 413,832.99 167,347 9,273 - 439,659 36.12 12,172 1997 148,860.34 57,427 3,182 - 157,997 36.19 4,366 1998 1,864,632.07 700,756 38,830 - 1,978,047 36.23 54,597 1999 105,149.44 38,472 2,132 - 111,487 36.26 3,075 2000 43,680.64 15,530 861 - 46,288 36.29 1,276 2001 31,488.40 10,850 601 - 33,349 36.33 918 2009 21,780.07 5,292 293 - 22,945 36.58 627 2010 4,979,946.67 1,135,476 62,918 - 5,242,063 36.61 143,187 2013 34,720.97 6,230 345 - 36,455 36.69 994 2014 789,164.05 127,599 7,070 - 827,801 36.72 22,544 2015 4,281,937.45 613,341 33,986 - 4,487,201 36.75 122,101 2016 8,155,651.17 1,011,464 56,047 - 8,537,924 36.78 232,135 2017 2,479,815.97 257,333 14,259 - 2,593,268 36.81 70,450 2018 6,133,713.65 505,413 28,006 - 6,407,068 36.84 173,916 2019 298,144.08 18,062 1,001 - 311,071 36.86 8,439 2021 29,972.83 384 21 - 31,193 36.92 845 30,792,771.90 5,324,726 295,051 - 32,319,534 886,452 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1906 244,325.25 186,216 174,193 79,905 28.12 2,842 1907 6,605.11 5,020 4,696 2,173 28.27 77 1908 5,823.00 4,413 4,128 1,928 28.43 68 1909 23,882.00 18,049 16,884 7,954 28.58 278 1912 507.00 380 355 172 29.03 6 1914 83.00 62 58 28 29.32 1 1918 177.00 130 122 62 29.87 2 1920 5,524.00 4,039 3,778 1,967 30.14 65 1921 2,163.00 1,576 1,474 775 30.28 26 1922 90,569.16 65,798 61,550 32,642 30.41 1,073 1924 418.00 302 283 152 30.66 5 1925 1,699.00 1,222 1,143 624 30.79 20 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-66 Attachment C J. Spanos, Avista Page 546 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.00 RESERVOIRS, DAMS AND WATERWAYS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1927 3,499.00 2,500 2,339 1,300 31.03 42 1928 1,933.00 1,376 1,287 723 31.15 23 1929 10,164.00 7,211 6,745 3,825 31.27 122 1930 9,741.00 6,886 6,441 3,689 31.39 118 1931 2,027.00 1,428 1,336 772 31.50 25 1932 81.00 57 53 31 31.62 1 1933 444.00 310 290 172 31.73 5 1936 295.62 204 191 117 32.06 4 1937 382.00 263 246 151 32.17 5 1939 10.00 7 7 4 32.38 1940 10.00 7 7 4 32.48 1941 217.00 147 138 88 32.58 3 1946 318.00 210 196 134 33.07 4 1947 940.00 619 579 399 33.16 12 1948 3,053.00 2,001 1,872 1,303 33.25 39 1950 1,353.00 878 821 586 33.43 18 1951 187.00 121 113 81 33.52 2 1953 687.00 439 411 304 33.69 9 1954 15,763.00 10,011 9,365 7,029 33.77 208 1955 4,120.20 2,602 2,434 1,851 33.85 55 1956 181.00 114 107 82 33.93 2 1957 1,817.00 1,134 1,061 829 34.01 24 1958 3,501.55 2,172 2,032 1,610 34.09 47 1961 187.00 114 107 88 34.32 3 1967 1,208.96 705 659 598 34.73 17 1968 12,858.59 7,435 6,955 6,418 34.80 184 1969 232.00 133 124 117 34.86 3 1970 1,067.88 608 569 542 34.92 16 1973 1,196.19 663 620 624 35.10 18 1976 140,946.68 75,830 70,934 75,651 35.27 2,145 1977 58,436.39 31,109 29,100 31,673 35.33 896 1979 1,043.87 544 509 577 35.43 16 1980 54,358.99 27,993 26,186 30,348 35.48 855 1986 2,022.16 963 901 1,202 35.76 34 1987 16,685.67 7,825 7,320 10,033 35.80 280 1988 118,664.01 54,775 51,238 72,172 35.85 2,013 1989 194.55 88 82 120 35.89 3 1990 7,682.02 3,429 3,208 4,782 35.93 133 1991 3,819.62 1,675 1,567 2,406 35.97 67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-67 Attachment C J. Spanos, Avista Page 547 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.00 RESERVOIRS, DAMS AND WATERWAYS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1992 856,558.02 368,541 344,746 546,075 36.01 15,165 1993 710,712.90 299,803 280,446 458,696 36.05 12,724 1995 337,561.33 136,504 127,690 223,373 36.12 6,184 1996 364,802.18 144,121 134,816 244,579 36.16 6,764 1997 335,085.62 129,269 120,923 227,566 36.19 6,288 1999 47,839.08 17,503 16,373 33,380 36.26 921 2004 1,953,993.11 605,846 566,729 1,465,424 36.42 40,237 2005 35,164.03 10,464 9,788 26,782 36.45 735 2010 321,999.59 73,419 68,679 266,201 36.61 7,271 2011 27,759.75 5,894 5,513 23,357 36.64 637 2013 5,142,129.71 922,659 863,087 4,484,728 36.69 122,233 2015 69,228.46 9,916 9,276 62,722 36.75 1,707 2016 13,289,931.86 1,648,217 1,541,798 12,279,731 36.78 333,870 24,355,870.11 4,913,949 4,596,675 20,733,430 566,650 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 1952 16,083,649.66 10,146,110 8,755,562 9,418,962 41.44 227,292 1953 16,881.00 10,579 9,129 9,946 41.58 239 1954 11,285.00 7,024 6,061 6,691 41.72 160 1955 757.00 468 404 452 41.86 11 1956 35.00 21 18 21 42.00 1962 21,885.00 12,830 11,072 13,658 42.78 319 1968 7,167.00 3,985 3,439 4,660 43.49 107 1973 8,474.82 4,479 3,865 5,711 44.03 130 1990 15,731.02 6,491 5,601 12,175 45.51 268 1992 124,016.42 49,092 42,364 97,775 45.66 2,141 1995 947.93 350 302 769 45.86 17 1999 419,024.28 138,564 119,573 353,924 46.12 7,674 2000 245.40 79 68 209 46.18 5 2001 7,739.22 2,398 2,069 6,676 46.24 144 2004 19,473.21 5,378 4,641 17,364 46.41 374 2006 150,851.84 38,032 32,820 137,643 46.52 2,959 2009 52,507.35 11,180 9,648 49,686 46.69 1,064 2012 388,448.73 65,991 56,947 382,000 46.85 8,154 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-68 Attachment C J. Spanos, Avista Page 548 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.00 RESERVOIRS, DAMS AND WATERWAYS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 2014 4,435,996.02 615,356 531,020 4,481,655 46.95 95,456 2015 37,344.55 4,564 3,938 38,261 47.00 814 2016 2,582,504.81 272,183 234,880 2,683,351 47.05 57,032 2017 2,387,551.83 209,252 180,574 2,517,360 47.10 53,447 2020 68,445.10 2,118 1,828 75,515 47.24 1,599 26,840,962.19 11,606,524 10,015,823 20,314,465 459,406 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 1959 26,625,661.63 16,202,921 11,819,063 20,397,988 46.63 437,443 1960 217,612.00 131,302 95,777 167,534 46.80 3,580 1961 274,765.94 164,335 119,873 212,594 46.97 4,526 1962 5,704.87 3,382 2,467 4,436 47.13 94 1963 131,429.70 77,223 56,330 102,700 47.29 2,172 1964 232.00 135 98 182 47.44 4 1965 77,152.71 44,491 32,454 60,901 47.60 1,279 1966 107,377.41 61,329 44,736 85,191 47.75 1,784 1967 116,794.92 66,048 48,178 93,144 47.90 1,945 1968 110,343.80 61,771 45,058 88,458 48.05 1,841 1969 105,493.73 58,440 42,628 85,019 48.20 1,764 1970 45,627.49 25,009 18,243 36,967 48.34 765 1971 9,701.00 5,259 3,836 7,902 48.48 163 1972 5,156.74 2,764 2,016 4,223 48.62 87 1977 717,636.57 361,916 263,996 604,344 49.27 12,266 1978 15,194.26 7,560 5,515 12,870 49.40 261 1988 20,800.16 8,812 6,428 18,740 50.52 371 1990 146,303.21 59,550 43,438 133,589 50.72 2,634 1991 369.25 147 107 340 50.81 7 1992 410,372.13 159,984 116,699 379,852 50.91 7,461 1993 385.55 147 107 359 51.00 7 1994 8,646.60 3,216 2,346 8,117 51.09 159 1998 81,856.82 27,276 19,896 79,151 51.44 1,539 1999 6,099.21 1,970 1,437 5,943 51.52 115 2000 509,731.73 159,227 116,147 500,629 51.61 9,700 2003 122,811.03 34,322 25,036 123,565 51.84 2,384 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-69 Attachment C J. Spanos, Avista Page 549 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.00 RESERVOIRS, DAMS AND WATERWAYS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 110-R1 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2007 94,218.74 21,790 15,895 98,110 52.14 1,882 2009 47,795.27 9,793 7,143 50,689 52.29 969 2010 149,976.46 28,683 20,923 160,549 52.36 3,066 2012 47,015.14 7,645 5,577 51,312 52.50 977 2014 74,467.55 9,865 7,196 82,910 52.63 1,575 2015 252,620.21 29,409 21,452 284,218 52.70 5,393 2017 450,612.89 37,485 27,343 517,899 52.83 9,803 2018 244,117.99 16,104 11,747 283,636 52.89 5,363 2019 1,350,634.16 64,619 47,136 1,587,132 52.96 29,969 2020 553.41 16 12 658 53.02 12 2021 15,045.63 150 109 18,096 53.08 341 32,600,317.91 17,954,095 13,096,439 26,349,945 553,701 176,364,942.46 59,242,858 52,213,550 140,435,155 3,623,229 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 38.8 2.05 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-70 Attachment C J. Spanos, Avista Page 550 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.10 RESERVOIRS, DAMS AND WATERWAYS - FISH AND WILDLIFE CONSERVATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 2013 11,906.30 2,627 2,057 10,564 32.11 329 2014 33,137.10 6,597 5,166 29,959 32.26 929 2016 10,805.87 1,651 1,293 10,161 32.55 312 2019 27,931.35 2,090 1,637 27,971 32.92 850 83,780.62 12,965 10,152 78,655 2,420 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1999 3,534.58 1,462 1,261 2,415 32.41 75 2017 78,923.35 8,908 7,682 74,398 36.88 2,017 82,457.93 10,370 8,943 76,813 2,092 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1994 16,133.11 7,607 6,662 10,116 30.83 328 2014 869,271.88 154,121 134,982 769,060 36.30 21,186 2019 54,885.10 3,593 3,147 53,934 37.22 1,449 2020 428,957.73 17,211 15,074 431,042 37.38 11,531 1,369,247.82 182,532 159,865 1,264,152 34,494 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 1985 1,041,666.96 594,051 581,429 595,654 31.23 19,073 1991 113,057.55 57,075 55,862 71,893 34.18 2,103 2001 254,391.49 95,854 93,817 193,645 39.04 4,960 2004 1,174,709.15 391,138 382,828 944,594 40.43 23,364 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-71 Attachment C J. Spanos, Avista Page 551 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.10 RESERVOIRS, DAMS AND WATERWAYS - FISH AND WILDLIFE CONSERVATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 2005 297,752.55 94,502 92,494 243,966 40.89 5,966 2006 39,583.07 11,944 11,690 33,039 41.34 799 2007 4,065,953.80 1,161,175 1,136,504 3,458,024 41.78 82,767 2008 5,289,595.63 1,423,899 1,393,646 4,583,597 42.21 108,590 2009 115,871.84 29,240 28,619 102,316 42.64 2,400 2010 52,976.34 12,455 12,190 47,673 43.05 1,107 2012 259,225.12 51,654 50,557 242,368 43.86 5,526 2013 3,202,646.27 578,532 566,240 3,052,750 44.25 68,989 2014 98,420.34 15,890 15,552 95,663 44.63 2,143 2015 117,523.69 16,671 16,317 116,485 45.00 2,589 2016 99,524.98 12,122 11,864 100,599 45.36 2,218 2018 70,331.01 5,615 5,496 73,978 46.04 1,607 2019 60,281.70 3,471 3,397 64,721 46.37 1,396 16,353,511.49 4,555,288 4,458,504 14,020,964 335,597 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 1995 50,000.00 23,669 25,572 34,928 38.03 918 2001 567,200.24 219,277 236,908 449,404 41.49 10,832 2003 388,122.03 137,948 149,040 320,588 42.63 7,520 2006 624,603.14 191,550 206,951 548,818 44.30 12,389 2007 92,181.60 26,693 28,839 82,701 44.85 1,844 2009 66,513.05 16,935 18,297 62,184 45.93 1,354 2010 181,464.40 42,926 46,377 173,194 46.46 3,728 2011 11,139.31 2,434 2,630 10,849 46.97 231 2012 36,428.89 7,272 7,857 36,222 47.48 763 2013 43,446.28 7,848 8,479 44,091 47.98 919 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-72 Attachment C J. Spanos, Avista Page 552 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.10 RESERVOIRS, DAMS AND WATERWAYS - FISH AND WILDLIFE CONSERVATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2014 119,324.38 19,213 20,758 123,625 48.47 2,551 2016 86,688.16 10,470 11,312 93,581 49.42 1,894 2020 66,113.89 2,278 2,461 77,537 51.17 1,515 2,333,225.37 708,513 765,480 2,057,722 46,458 20,222,223.23 5,469,668 5,402,945 17,498,306 421,061 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 41.6 2.08 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-73 Attachment C J. Spanos, Avista Page 553 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.15 RESERVOIRS, DAMS AND WATERWAYS - FISH AND WILDLIFE CONSERVATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 2015 11,034.00 1,728 1,291 10,184 36.50 279 11,034.00 1,728 1,291 10,184 279 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 2004 979,038.74 325,986 294,662 811,652 40.43 20,075 2005 14,182.39 4,501 4,068 11,958 40.89 292 2007 10,037.72 2,867 2,592 8,751 41.78 209 2013 70,719.45 12,775 11,547 68,366 44.25 1,545 2015 29,754.56 4,221 3,815 29,807 45.00 662 2017 117,599.67 11,862 10,722 122,165 45.71 2,673 2018 18,001.42 1,437 1,299 19,043 46.04 414 2020 82,934.19 2,917 2,637 91,079 46.68 1,951 2021 172,392.89 2,051 1,854 192,950 46.97 4,108 1,494,661.03 368,617 333,197 1,355,770 31,929 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2002 218,446.08 81,109 114,319 150,000 42.06 3,566 2003 262,682.40 93,364 131,592 186,253 42.63 4,369 2013 55,363.85 10,001 14,096 52,894 47.98 1,102 2015 34,414.27 4,855 6,843 34,798 48.95 711 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-74 Attachment C J. Spanos, Avista Page 554 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.15 RESERVOIRS, DAMS AND WATERWAYS - FISH AND WILDLIFE CONSERVATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2016 321,885.97 38,878 54,797 334,685 49.42 6,772 2019 56,180.06 3,192 4,499 63,479 50.75 1,251 2020 7,206.12 248 350 8,370 51.17 164 956,178.75 231,647 326,496 830,480 17,935 2,461,873.78 601,992 660,984 2,196,434 50,143 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 43.8 2.04 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-75 Attachment C J. Spanos, Avista Page 555 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.20 RESERVOIRS, DAMS AND WATERWAYS - RECREATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LITTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2059 NET SALVAGE PERCENT.. -5 1991 14,365.60 7,352 10,198 4,886 29.38 166 14,365.60 7,352 10,198 4,886 166 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 1975 48,511.99 32,301 51,423 1976 2,465.61 1,625 2,605 8 23.17 1978 13,954.84 9,005 14,437 356 23.74 15 1989 188.86 105 168 32 26.80 1 1990 13,035.96 7,128 11,427 2,391 27.07 88 1994 27,482.17 13,916 22,310 6,821 28.11 243 105,639.43 64,080 102,370 9,608 347 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1992 47,371.90 23,327 613 48,653 30.18 1,612 47,371.90 23,327 613 48,653 1,612 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1982 119,926.17 69,920 23,763 100,961 26.79 3,769 1989 57,594.29 30,056 10,215 49,683 29.18 1,703 1995 29,757.16 13,705 4,658 26,290 31.15 844 2021 131,592.83 1,800 612 136,245 37.53 3,630 338,870.45 115,481 39,247 313,179 9,946 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-76 Attachment C J. Spanos, Avista Page 556 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 332.20 RESERVOIRS, DAMS AND WATERWAYS - RECREATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 1986 9,716.14 5,440 6,392 4,587 31.72 145 1987 10,065.97 5,529 6,497 4,878 32.21 151 1990 2,209.51 1,141 1,341 1,156 33.68 34 1991 45,757.93 23,100 27,143 24,564 34.18 719 1992 34,820.80 17,177 20,183 19,164 34.67 553 102,570.35 52,387 61,556 54,349 1,602 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 65-S1.5 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 1986 20,363.37 11,961 9,032 15,608 32.89 475 1987 23,577.46 13,571 10,248 18,281 33.45 547 1990 2,209.51 1,191 899 1,774 35.15 50 2002 13,360.57 4,961 3,746 12,420 42.06 295 2006 7,558.01 2,318 1,750 7,395 44.30 167 67,068.92 34,002 25,675 55,478 1,534 675,886.65 296,629 239,659 486,153 15,207 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 32.0 2.25 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-77 Attachment C J. Spanos, Avista Page 557 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 333.00 TURBINES AND GENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 MONROE STREET INTERIM SURVIVOR CURVE.. IOWA 70-S0 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -7 1992 10,698,553.69 4,338,699 2,867,348 8,580,105 37.75 227,288 1993 47,921.96 19,036 12,580 38,696 37.97 1,019 1994 233,266.47 90,633 59,897 189,698 38.20 4,966 1998 8,786.44 3,090 2,042 7,359 39.09 188 2009 12,830.06 2,880 1,903 11,825 41.58 284 2018 573,612.36 43,479 28,734 585,031 43.81 13,354 11,574,970.98 4,497,817 2,972,505 9,412,714 247,099 LITTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 70-S0 PROBABLE RETIREMENT YEAR.. 12-2059 NET SALVAGE PERCENT.. -5 1924 15,917.00 12,854 16,713 1930 9,803.55 7,595 9,920 374 18.33 20 1942 12,433.62 8,923 11,655 1,401 21.93 64 1956 34,365.81 22,634 29,563 6,521 25.13 259 1968 4,702.10 2,848 3,720 1,217 27.32 45 1970 27,729.50 16,529 21,589 7,527 27.65 272 1976 332.80 188 246 104 28.59 4 1977 153,756.53 86,072 112,422 49,022 28.74 1,706 1986 18,457.89 9,306 12,155 7,226 30.03 241 1987 147,285.09 73,222 95,638 59,011 30.17 1,956 1989 677,065.53 326,745 426,775 284,144 30.44 9,335 1990 7,668.42 3,642 4,757 3,295 30.58 108 1991 21,613.83 10,096 13,187 9,508 30.71 310 1994 977.15 432 564 462 31.12 15 1995 451,113.28 195,327 255,124 218,545 31.25 6,993 1996 254,977.38 108,017 141,085 126,641 31.39 4,034 2000 42,771.56 16,405 21,427 23,483 31.92 736 2001 980,043.21 364,972 476,705 552,341 32.06 17,228 2002 318.11 115 150 184 32.19 6 2016 14,186,359.59 1,972,932 2,576,926 12,318,752 34.19 360,303 2017 9,447,688.05 1,103,608 1,441,467 8,478,606 34.35 246,830 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-78 Attachment C J. Spanos, Avista Page 558 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 333.00 TURBINES AND GENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LITTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 70-S0 PROBABLE RETIREMENT YEAR.. 12-2059 NET SALVAGE PERCENT.. -5 2018 6,673,830.60 625,141 816,522 6,191,000 34.51 179,397 2019 5,905,121.05 406,001 530,294 5,670,083 34.68 163,497 2021 126,207.61 1,827 2,386 130,132 35.04 3,714 39,200,539.26 5,375,431 7,020,990 34,139,577 997,073 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 70-S0 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 1915 358,093.27 311,091 379,579 1916 1,032.00 890 1,094 1917 2,916.00 2,499 3,091 1918 134,215.00 114,221 142,268 1919 237,864.19 201,061 252,136 1920 21,377.00 17,946 22,660 1921 1,259.00 1,050 1,335 1922 1,177.00 975 1,248 1923 297,923.00 245,198 315,798 1924 6,537.53 5,346 6,930 1925 148.00 120 157 1926 686.00 554 727 1929 321.00 254 340 1930 164.00 129 174 1931 5,240.00 4,106 5,554 1941 277.00 205 294 1942 990.00 730 1,049 1943 146.00 107 155 1946 1,771.36 1,279 1,878 1947 50.27 36 53 1951 1,647.52 1,158 1,746 1953 479.00 333 508 1954 91.61 63 97 1955 3,458.58 2,379 3,666 1956 67,761.00 46,335 71,827 1957 69,349.93 47,147 73,511 1958 65,764.00 44,450 69,710 1959 73,640.50 49,481 78,059 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-79 Attachment C J. Spanos, Avista Page 559 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 333.00 TURBINES AND GENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 70-S0 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 1969 8,435.00 5,310 8,941 1975 58,363.08 35,039 61,865 1977 1,018.76 601 1,080 1979 1,820.23 1,053 1,929 1980 59,043.70 33,821 62,586 1981 12,622.22 7,155 13,380 1982 15,835.74 8,880 16,786 1986 3,216.24 1,720 3,409 1987 264,804.37 139,737 280,693 1989 454.40 233 482 1991 514,234.97 255,734 545,089 1992 8,195.23 4,008 8,687 1995 2,349,909.47 1,087,603 2,370,703 120,201 28.67 4,193 1996 81,231.80 36,829 80,278 5,828 28.78 203 1997 1,205,376.98 534,692 1,165,495 112,204 28.89 3,884 1999 1,828,077.35 773,031 1,685,015 252,747 29.11 8,682 2000 813,955.47 335,368 731,019 131,774 29.22 4,510 2001 123,567.44 49,503 107,904 23,077 29.33 787 2005 31,256.40 10,947 23,862 9,270 29.77 311 8,735,798.61 4,420,407 8,604,845 655,101 22,570 SPOKANE UPPER FALLS INTERIM SURVIVOR CURVE.. IOWA 70-S0 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -6 1922 335,145.59 277,098 355,254 1923 986.00 809 1,045 1924 91.00 74 96 1927 21.00 17 22 1929 12,844.00 10,102 13,615 1930 6,333.00 4,947 6,713 1931 210.00 163 223 1942 45.00 32 48 1949 5,615.33 3,879 5,952 1950 4,981.00 3,420 5,280 1951 302.00 206 320 1957 4.09 3 4 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-80 Attachment C J. Spanos, Avista Page 560 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 333.00 TURBINES AND GENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SPOKANE UPPER FALLS INTERIM SURVIVOR CURVE.. IOWA 70-S0 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -6 1963 5,752.00 3,622 6,097 1964 2,535.00 1,585 2,687 1966 561.00 346 595 1967 36,810.84 22,496 39,019 1968 1,470.00 891 1,558 1977 5,900.21 3,301 6,254 1998 603,316.52 242,856 639,516 1999 35,727.50 14,014 37,871 2000 304.18 116 322 2007 46,286.54 13,635 45,002 4,062 33.57 121 2010 49,862.76 12,423 41,002 11,853 34.01 349 2021 25,937.41 378 1,248 26,246 35.83 733 1,181,041.97 616,413 1,209,744 42,161 1,203 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 70-S0 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1908 29,525.27 26,359 8,201 - 38,907 9.91 3,926 1909 24,824.00 22,022 6,851 - 32,668 10.29 3,175 1938 1,274.00 926 288 - 1,613 20.99 77 1994 3,059,415.18 1,321,494 411,134 - 3,592,926 31.73 113,234 1995 318,116.54 134,603 41,877 - 372,718 31.87 11,695 1996 3,520.28 1,457 453 - 4,114 32.01 129 1997 87,404.22 35,362 11,002 - 101,902 32.15 3,170 1998 149,820.93 59,170 18,409 - 174,222 32.29 5,396 1999 14,013.64 5,393 1,678 - 16,252 32.43 501 2000 2,358.42 883 275 - 2,727 32.57 84 2001 11,959.21 4,348 1,353 - 13,790 32.71 422 2003 3,747.93 1,277 397 - 4,295 32.99 130 2009 136,761.66 35,567 11,065 - 153,297 33.86 4,527 2014 3,645,686.21 638,453 198,631 - 3,990,145 34.62 115,255 2016 32,005,502.76 4,326,478 1,346,023 - 34,631,746 34.94 991,178 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-81 Attachment C J. Spanos, Avista Page 561 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 333.00 TURBINES AND GENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 70-S0 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 2018 1,536,108.53 139,291 43,335 - 1,640,888 35.28 46,510 2020 89,769.83 3,698 1,150 - 94,511 35.64 2,652 2021 14,659.38 210 65 - 15,311 35.83 427 41,134,467.99 6,756,991 2,102,188 - 44,882,034 1,302,488 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 70-S0 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1906 172,805.06 156,252 179,717 1907 42,313.00 38,021 44,006 1908 88,684.00 79,174 92,231 1909 1,787.00 1,585 1,858 1910 56.00 49 58 1913 268.00 232 279 1916 40.00 34 42 1926 399.00 314 415 1928 571.00 444 594 1929 2,171.00 1,675 2,258 1940 370.00 265 385 1941 489.00 349 509 1942 1,256.00 890 1,306 1948 933.00 636 970 1949 117.00 79 122 1958 18,352.00 11,739 19,086 1959 22,327.00 14,186 23,220 1962 21,610.00 13,449 22,474 1963 18,588.00 11,485 19,332 1964 90.00 55 94 1967 46,836.00 28,083 48,709 1968 11,611.00 6,908 12,075 1974 36,182.52 20,449 37,630 1980 1,233,058.12 655,848 1,282,380 1981 29,320.62 15,421 30,493 1982 11,033.71 5,736 11,475 1993 5,554.62 2,447 5,222 554 31.59 18 1996 437,326.88 181,055 386,415 68,405 32.01 2,137 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-82 Attachment C J. Spanos, Avista Page 562 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 333.00 TURBINES AND GENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 70-S0 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1997 9,974.83 4,036 8,614 1,760 32.15 55 1998 651.74 257 549 129 32.29 4 2004 6,499.88 2,134 4,554 2,205 33.14 67 2005 12,374.89 3,909 8,343 4,527 33.28 136 2,233,650.87 1,257,196 2,245,416 77,581 2,417 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 70-S0 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 1952 1,914,061.04 1,319,752 916,467 1,246,422 27.10 45,993 1953 4,419,657.00 3,021,698 2,098,338 2,895,875 27.43 105,573 1954 1,292.00 876 608 852 27.76 31 1955 806.00 542 376 534 28.08 19 1956 3,163.00 2,107 1,463 2,111 28.40 74 1973 1,473.72 835 580 1,085 33.23 33 1984 10,197.16 5,020 3,486 8,037 35.92 224 1985 141,693.68 68,718 47,719 112,394 36.15 3,109 1986 242,867.50 115,937 80,509 193,931 36.38 5,331 1988 445,904.96 205,918 142,994 360,878 36.84 9,796 1990 246,368.23 109,713 76,187 202,209 37.30 5,421 1991 410.30 179 124 339 37.52 9 1992 1,604,682.35 687,255 477,246 1,336,045 37.75 35,392 1993 758,371.57 318,146 220,928 636,032 37.97 16,751 1995 158,401.82 63,532 44,118 134,876 38.42 3,511 1996 1,677.39 657 456 1,439 38.64 37 1998 194,259.99 72,154 50,105 169,408 39.09 4,334 2000 131,181.92 45,971 31,923 116,312 39.53 2,942 2001 7,634,067.19 2,590,105 1,798,630 6,827,866 39.76 171,727 2003 59,157.59 18,703 12,988 53,860 40.21 1,339 2004 5,705,639.58 1,735,375 1,205,085 5,242,288 40.43 129,663 2007 5,911,893.88 1,569,102 1,089,621 5,590,819 41.11 135,997 2008 115,256.58 28,997 20,136 110,104 41.34 2,663 2009 17,279.66 4,097 2,845 16,681 41.58 401 2011 429,783.10 88,962 61,777 423,878 42.05 10,080 2012 10,556.87 2,016 1,400 10,529 42.29 249 2016 14,433,912.90 1,734,440 1,204,436 15,105,886 43.28 349,027 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-83 Attachment C J. Spanos, Avista Page 563 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 333.00 TURBINES AND GENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 70-S0 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 2018 1,047,681.79 83,866 58,239 1,125,642 43.81 25,694 2020 348,040.36 12,617 8,762 384,524 44.36 8,668 2021 880,223.71 10,792 7,494 987,159 44.66 22,104 46,869,962.84 13,918,082 9,665,042 43,298,016 1,096,192 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 70-S0 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 1959 3,551,488.81 2,417,533 2,008,389 2,288,913 30.41 75,268 1960 3,666,192.00 2,470,682 2,052,543 2,383,550 30.77 77,463 1961 13,616.67 9,085 7,547 8,929 31.12 287 1966 84.00 53 44 58 32.85 2 1967 299.00 187 155 206 33.18 6 1970 8,423.00 5,100 4,237 5,955 34.17 174 1972 2,089.00 1,236 1,027 1,501 34.80 43 1975 20,157.99 11,498 9,552 14,839 35.74 415 1976 15,408.84 8,675 7,207 11,438 36.05 317 1977 11,771,037.47 6,542,074 5,434,890 8,808,065 36.35 242,313 1978 911,273.55 499,750 415,172 687,469 36.65 18,758 1979 549,153.50 297,087 246,808 417,668 36.95 11,304 1980 283.96 151 125 218 37.25 6 1983 881.97 450 374 693 38.12 18 1986 133,967.56 65,059 54,048 108,052 38.99 2,771 1988 18,454.30 8,653 7,189 15,141 39.55 383 1989 127,859.25 58,831 48,874 105,835 39.83 2,657 1990 154,906.76 69,893 58,064 129,373 40.11 3,225 1991 9,443.95 4,176 3,469 7,958 40.39 197 1992 52,354.82 22,667 18,831 44,519 40.67 1,095 1993 1,704,747.04 721,754 599,604 1,463,140 40.95 35,730 1997 41,632.43 15,965 13,263 37,112 42.05 883 1999 136,219.82 49,321 40,974 123,852 42.60 2,907 2000 426,439.23 149,612 124,292 391,700 42.88 9,135 2001 361,325.04 122,605 101,855 335,348 43.16 7,770 2002 283,560.76 92,921 77,195 265,914 43.43 6,123 2003 500,143.98 157,745 131,048 474,126 43.71 10,847 2004 368,835.16 111,724 92,816 353,475 43.99 8,035 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-84 Attachment C J. Spanos, Avista Page 564 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 333.00 TURBINES AND GENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 70-S0 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2005 2,644,629.80 767,168 637,332 2,562,670 44.27 57,887 2006 212,301.22 58,785 48,836 208,048 44.55 4,670 2007 7,860,050.32 2,069,805 1,719,510 7,791,151 44.83 173,793 2008 9,243,546.00 2,303,040 1,913,272 9,271,418 45.12 205,484 2009 17,733,990.85 4,159,873 3,455,854 18,002,275 45.41 396,439 2010 8,613,465.70 1,891,021 1,570,984 8,851,310 45.70 193,683 2011 9,064,936.25 1,849,959 1,536,871 9,431,702 45.99 205,082 2012 7,810,680.62 1,469,335 1,220,664 8,230,260 46.28 177,836 2015 668,809.21 91,155 75,728 733,531 47.19 15,544 2021 139,640.38 1,666 1,384 167,581 49.19 3,407 88,822,330.21 28,576,294 23,740,028 83,734,992 1,951,957 239,752,762.73 65,418,631 53,356,382 216,242,176 5,620,999 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 38.5 2.34 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-85 Attachment C J. Spanos, Avista Page 565 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 334.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 MONROE STREET INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -7 1992 772,086.19 429,382 109,820 716,312 19.21 37,288 1993 5,540.21 3,006 769 5,159 19.72 262 1994 340,906.88 180,197 46,088 318,683 20.24 15,745 1998 106,546.65 50,187 12,836 101,169 22.38 4,521 2001 21,074.38 8,953 2,290 20,260 24.07 842 2009 32,170.85 9,249 2,366 32,057 28.85 1,111 2012 5,653.02 1,292 330 5,718 30.75 186 2015 136,580.08 22,434 5,738 140,403 32.70 4,294 2016 686,497.65 97,071 24,827 709,725 33.36 21,275 2018 785,298.59 73,372 18,766 821,504 34.70 23,674 2019 140,015.82 9,477 2,424 147,393 35.39 4,165 2020 1,872.17 78 20 1,983 36.07 55 3,034,242.49 884,698 226,273 3,020,367 113,418 LITTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2059 NET SALVAGE PERCENT.. -5 1911 68,961.54 72,410 72,410 1912 1,325.00 1,391 1,391 1913 1,227.00 1,288 1,288 1915 7,485.00 7,859 7,859 1916 310.00 326 326 1921 90.00 94 95 1924 1,720.00 1,806 1,806 1927 1,870.00 1,964 1,964 1934 619.00 650 650 1936 964.00 1,012 1,012 1937 636.00 668 668 1939 2,806.60 2,947 2,947 1940 1,271.00 1,335 1,335 1944 82.00 84 85 1 0.90 1 1947 373.00 373 379 13 1.93 7 1948 77.00 76 77 4 2.27 2 1970 25,492.84 20,183 20,506 6,262 9.84 636 1971 4,978.00 3,893 3,955 1,272 10.21 125 1981 214,855.79 145,737 148,069 77,529 14.16 5,475 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-86 Attachment C J. Spanos, Avista Page 566 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 334.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LITTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2059 NET SALVAGE PERCENT.. -5 1982 80,425.43 53,666 54,525 29,922 14.58 2,052 1989 158,813.82 93,306 94,799 71,955 17.57 4,095 1992 283,044.62 156,186 158,685 138,512 18.86 7,344 1993 28,935.52 15,616 15,866 14,516 19.29 753 1998 9,880.72 4,702 4,777 5,598 21.45 261 1999 36,697.93 16,970 17,242 21,291 21.88 973 2002 132,588.35 55,680 56,571 82,647 23.18 3,565 2005 102,110.49 38,183 38,794 68,422 24.48 2,795 2009 51,188.53 15,625 15,875 37,873 26.23 1,444 2010 7,553.83 2,163 2,198 5,734 26.67 215 2011 4,124.17 1,101 1,119 3,212 27.11 118 2013 3,361,028.13 757,517 769,639 2,759,441 27.99 98,587 2015 3,344,116.49 603,351 613,006 2,898,316 28.87 100,392 2016 1,389,375.33 217,295 220,772 1,238,072 29.31 42,241 2017 311,435.28 40,781 41,434 285,573 29.76 9,596 2018 987,768.90 103,280 104,933 932,225 30.20 30,868 2019 3,270,053.24 250,306 254,311 3,179,244 30.65 103,727 2021 69,584.27 1,117 1,135 71,929 31.55 2,280 13,963,868.82 2,690,941 2,732,501 11,929,561 417,552 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 1915 71,899.98 76,214 76,214 1917 594.00 630 630 1918 19,449.00 20,616 20,616 1919 48,717.00 51,640 51,640 1920 11,340.00 12,020 12,020 1922 9,844.00 10,435 10,435 1923 14,511.00 15,382 15,382 1924 19,826.50 21,016 21,016 1925 271.00 287 287 1926 3,874.00 4,106 4,106 1928 219.00 232 232 1929 819.00 868 868 1930 27,496.00 29,146 29,146 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-87 Attachment C J. Spanos, Avista Page 567 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 334.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 1931 3,768.00 3,994 3,994 1932 263.00 279 279 1936 690.00 731 731 1937 815.00 864 864 1938 149.00 158 158 1941 976.00 1,035 1,035 1952 1,093.47 1,054 1,159 1954 4,481.67 4,241 4,751 1962 912.93 798 968 1964 147.34 126 156 1966 6,567.00 5,499 6,961 1977 189.82 138 201 1979 10,636.96 7,520 11,275 1980 179,195.39 124,778 189,947 1981 118,646.67 81,379 125,765 1982 26,704.92 18,029 28,307 1986 4,785.08 3,024 5,072 1987 194,029.64 120,478 205,671 1989 5,821.95 3,486 6,171 1990 3,636.30 2,137 3,854 1992 91,169.98 51,493 95,498 1,142 18.43 62 1993 57,432.87 31,770 58,920 1,959 18.81 104 1994 17,638.08 9,551 17,713 983 19.19 51 1995 360,296.83 190,763 353,785 28,130 19.57 1,437 1996 190,998.85 98,759 183,156 19,302 19.95 968 1997 610,187.98 307,896 571,018 75,782 20.33 3,728 1999 86,833.85 41,568 77,091 14,953 21.08 709 2002 48,950.91 21,384 39,658 12,230 22.21 551 2004 107,892.47 43,923 81,459 32,907 22.95 1,434 2005 204.15 80 148 68 23.32 3 2006 33,729.59 12,646 23,453 12,300 23.70 519 2007 74,789.15 26,782 49,669 29,607 24.07 1,230 2013 383,540.03 92,072 170,755 235,798 26.30 8,966 2014 216,867.48 47,086 87,325 142,555 26.67 5,345 2015 61,606.80 11,891 22,053 43,250 27.04 1,599 2016 89,978.81 15,086 27,978 67,399 27.41 2,459 2018 321,633.42 36,258 67,243 273,688 28.15 9,722 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-88 Attachment C J. Spanos, Avista Page 568 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 334.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 2019 8,089.94 671 1,244 7,331 28.52 257 2020 294,631.97 15,122 28,045 284,265 28.89 9,840 2021 655,197.71 11,439 21,215 673,295 29.27 23,003 4,504,041.49 1,688,580 2,817,339 1,956,945 71,987 SPOKANE UPPER FALLS INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -6 1998 173,603.18 83,028 73,307 110,713 21.59 5,128 1999 16,840.72 7,822 6,906 10,945 22.04 497 2000 17.14 8 7 11 22.48 2001 160,365.67 69,916 61,730 108,258 22.93 4,721 2008 1,416,824.50 458,195 404,548 1,097,286 26.08 42,074 2009 2,484,859.53 758,525 669,714 1,964,238 26.53 74,038 2014 2,087.30 423 373 1,839 28.82 64 2020 44,200.04 2,069 1,827 45,025 31.60 1,425 4,298,798.08 1,379,986 1,218,411 3,338,315 127,947 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1908 26,357.96 27,412 27,412 1909 2,930.00 3,047 3,047 1925 145.00 151 151 1930 1,111.00 1,155 1,155 1936 7,495.00 7,795 7,795 1940 448.00 466 466 1941 115.51 120 120 1956 2,745.69 2,501 1,281 1,574 4.96 317 1969 1,626.73 1,291 661 1,030 9.48 109 1988 126,187.34 74,784 38,308 92,927 17.18 5,409 1989 1,565.55 910 466 1,162 17.62 66 1992 955.32 521 267 727 18.94 38 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-89 Attachment C J. Spanos, Avista Page 569 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 334.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1994 1,966,323.11 1,023,776 524,426 1,520,550 19.82 76,718 1995 10,438.87 5,305 2,717 8,139 20.26 402 1996 3,140.60 1,555 797 2,470 20.71 119 2000 41,885.98 18,516 9,485 34,077 22.48 1,516 2001 2,287.04 978 501 1,878 22.93 82 2004 14,432.72 5,533 2,834 12,176 24.27 502 2013 176,797.98 39,021 19,988 163,882 28.36 5,779 2014 383,374.18 76,297 39,083 359,626 28.82 12,478 2016 14,494,372.62 2,213,940 1,134,084 13,940,064 29.74 468,731 2017 42,578.03 5,451 2,792 41,489 30.20 1,374 2018 57,320.85 5,839 2,991 56,623 30.67 1,846 2019 20,167.84 1,507 772 20,203 31.13 649 2020 537,362.90 24,679 12,642 546,216 31.60 17,285 2021 658,283.35 10,303 5,278 679,337 32.07 21,183 18,580,449.17 3,552,853 1,839,520 17,484,147 614,603 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1906 18,565.11 19,308 19,308 1907 2,547.00 2,649 2,649 1908 376.00 391 391 1911 3,311.00 3,443 3,443 1912 78.50 82 82 1923 86.00 89 89 1924 1,068.00 1,111 1,111 1925 48.00 50 50 1926 722.00 751 751 1930 3,831.00 3,984 3,984 1931 1,723.00 1,792 1,792 1932 105.00 109 109 1933 44.00 46 46 1937 6,528.00 6,789 6,789 1938 705.00 733 733 1939 50.00 52 52 1944 137.00 139 142 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-90 Attachment C J. Spanos, Avista Page 570 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 334.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1946 265.00 265 276 1949 407.00 396 423 1950 1,060.00 1,021 1,102 1954 97.00 90 101 1955 5,905.52 5,432 6,142 1956 260.00 237 270 1957 57,840.27 52,199 60,154 1958 2,713.00 2,424 2,822 1959 1,146.00 1,014 1,192 1960 582.00 510 605 1962 96.00 82 100 1964 243.00 204 253 1967 7,468.00 6,068 7,601 166 8.75 19 1968 14,049.00 11,283 14,133 477 9.11 52 1973 30,326.82 22,890 28,673 2,867 10.97 261 1980 193,821.69 132,334 165,766 35,809 13.74 2,606 1981 279.46 188 235 55 14.16 4 1983 13,662.20 8,877 11,120 3,089 15.01 206 1985 458.13 287 360 117 15.87 7 1986 1.00 1 1 1987 5,648.12 3,413 4,275 1,599 16.74 96 1990 306.00 174 218 100 18.06 6 1991 34,928.98 19,462 24,379 11,947 18.50 646 1992 35,532.45 19,373 24,267 12,686 18.94 670 1994 19,747.70 10,282 12,880 7,658 19.82 386 1996 49,081.98 24,309 30,450 20,595 20.71 994 1997 44,227.84 21,337 26,727 19,269 21.15 911 1998 29,893.08 14,027 17,571 13,518 21.59 626 2004 5,280.94 2,025 2,537 2,956 24.27 122 2006 21,365.10 7,510 9,407 12,812 25.17 509 2009 21,270.44 6,370 7,979 14,142 26.53 533 2010 31,955.20 8,978 11,246 21,987 26.99 815 2013 343,378.40 75,787 94,933 262,180 28.36 9,245 2016 543,205.11 82,972 103,934 461,000 29.74 15,501 2018 336,016.61 34,226 42,873 306,585 30.67 9,996 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-91 Attachment C J. Spanos, Avista Page 571 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 334.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 2019 11,094.57 829 1,038 10,500 31.13 337 2020 217,065.00 9,969 12,488 213,260 31.60 6,749 2021 327,670.46 5,129 6,425 334,353 32.07 10,426 2,448,273.68 633,492 776,477 1,769,728 61,723 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 1952 744,427.85 765,075 841,203 1953 87,873.08 89,491 99,297 1959 6,518.37 6,266 7,310 56 5.97 9 1977 8,908.35 6,916 8,068 1,998 12.52 160 1987 124,391.48 81,526 95,112 45,451 16.80 2,705 1988 16,546.93 10,625 12,396 6,302 17.27 365 1989 342,908.00 215,636 251,570 135,916 17.74 7,662 1990 4,251.73 2,616 3,052 1,753 18.22 96 1991 258,764.23 155,632 181,567 110,837 18.71 5,924 1993 31,274.13 17,917 20,903 14,437 19.72 732 1994 682,817.40 381,162 444,680 326,904 20.24 16,151 1996 10,214.41 5,397 6,296 5,246 21.29 246 1997 794,438.41 407,437 475,333 422,382 21.84 19,340 1998 525,245.20 261,282 304,823 288,705 22.38 12,900 1999 2,090.80 1,006 1,174 1,189 22.94 52 2001 79,744.72 35,778 41,740 48,371 24.07 2,010 2002 1,086.99 470 548 680 24.64 28 2003 12,466.22 5,172 6,034 8,053 25.22 319 2004 4,374.93 1,739 2,029 2,915 25.81 113 2005 111,993.56 42,471 49,548 77,004 26.41 2,916 2008 213,316.76 68,949 80,439 160,609 28.23 5,689 2011 144,050.44 37,842 44,148 118,629 30.11 3,940 2014 798,374.10 157,184 183,377 718,785 32.04 22,434 2016 2,267,016.10 338,532 394,946 2,166,783 33.36 64,952 2017 564,612.09 70,239 81,944 556,068 34.03 16,341 2018 952,041.21 93,939 109,593 966,213 34.70 27,845 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-92 Attachment C J. Spanos, Avista Page 572 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 334.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 2019 267,362.29 19,112 22,297 279,823 35.39 7,907 2020 4,159,638.12 182,845 213,315 4,487,076 36.07 124,399 2021 4,165,551.84 61,898 72,213 4,634,861 36.77 126,050 17,382,299.74 3,524,154 4,054,954 15,587,045 471,285 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 1992 12,963.64 8,153 4,717 10,969 19.21 571 1996 165,562.48 93,655 54,191 146,140 21.30 6,861 1997 102,674.94 56,372 32,618 91,619 21.85 4,193 1998 113,468.80 60,376 34,935 102,363 22.41 4,568 1999 1,418,263.53 730,200 422,508 1,293,591 22.98 56,292 2000 1,484,660.66 737,887 426,955 1,369,484 23.57 58,103 2001 2,279,856.65 1,092,416 632,093 2,126,534 24.16 88,019 2002 1,374,930.69 633,441 366,521 1,297,145 24.77 52,368 2003 1,052,551.64 464,974 269,043 1,004,545 25.39 39,565 2004 223,545.20 94,560 54,714 215,775 26.01 8,296 2005 243,908.27 98,402 56,937 238,192 26.65 8,938 2006 1,899,004.44 727,988 421,228 1,876,568 27.30 68,739 2008 1,021,722.93 349,337 202,133 1,034,152 28.64 36,109 2009 64,426.72 20,657 11,953 66,004 29.32 2,251 2013 111,251.69 25,573 14,797 119,818 32.15 3,727 2014 76,568.58 15,761 9,120 83,528 32.88 2,540 2015 208,716.63 37,748 21,842 230,705 33.63 6,860 2016 7,592.57 1,181 683 8,504 34.38 247 2017 5,439,852.93 702,718 406,606 6,175,616 35.14 175,743 2018 97,107.50 9,913 5,736 111,764 35.92 3,111 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-93 Attachment C J. Spanos, Avista Page 573 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 334.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 40-S0.5 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2019 419,274.07 31,139 18,018 489,304 36.70 13,333 2020 790,736.15 35,621 20,611 936,180 37.50 24,965 2021 1,007,120.38 15,708 9,089 1,209,527 38.30 31,580 19,615,761.09 6,043,780 3,497,046 20,238,025 696,979 83,827,734.56 20,398,484 17,162,521 75,324,133 2,575,494 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 29.2 3.07 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-94 Attachment C J. Spanos, Avista Page 574 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.00 MISCELLANEOUS POWER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 MONROE STREET INTERIM SURVIVOR CURVE.. IOWA 65-R1 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -7 1992 19,611.78 7,686 5,236 15,749 37.49 420 1993 13.74 5 3 11 37.79 1994 2.13 1 1 2 38.08 2002 4,550.56 1,316 897 3,973 40.21 99 2006 9,385.49 2,273 1,548 8,494 41.12 207 33,563.70 11,281 7,685 28,228 726 LITTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 65-R1 PROBABLE RETIREMENT YEAR.. 12-2059 NET SALVAGE PERCENT.. -5 1980 145.94 79 100 53 28.61 2 1982 10,604.49 5,564 7,049 4,085 29.05 141 1983 63.52 33 42 25 29.26 1 1985 9,920.34 4,980 6,309 4,107 29.68 138 1986 2,050.65 1,013 1,283 870 29.88 29 1990 8,316.42 3,836 4,860 3,872 30.64 126 1991 4,946.90 2,238 2,835 2,359 30.82 77 1992 3,645.77 1,617 2,049 1,779 30.99 57 1993 32,160.58 13,971 17,701 16,068 31.16 516 1994 3,217.00 1,368 1,733 1,645 31.32 53 1995 47,210.28 19,625 24,864 24,707 31.48 785 2000 1,832.30 667 845 1,079 32.21 33 2007 7,621.60 2,112 2,676 5,327 33.06 161 2015 108,745.80 15,942 20,198 93,985 33.83 2,778 2017 308,466.86 32,706 41,437 282,453 34.01 8,305 548,948.45 105,751 133,983 442,413 13,202 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 65-R1 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 1915 2,422.18 2,266 2,568 1916 4,287.67 3,990 4,545 1917 370.00 342 392 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-95 Attachment C J. Spanos, Avista Page 575 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.00 MISCELLANEOUS POWER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 65-R1 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 1919 167.00 153 177 1920 346.00 315 367 1922 38.00 34 40 1924 123.00 109 130 1925 116.00 102 123 1926 135.00 118 143 1937 262.00 213 278 1938 287.00 232 304 1939 82.00 66 87 1940 107.00 85 113 1945 206.30 159 213 6 17.75 1947 226.95 172 230 10 18.38 1 1948 1,032.86 777 1,041 54 18.69 3 1951 2,247.07 1,655 2,217 165 19.61 8 1955 865.46 619 829 88 20.77 4 1959 454.70 315 422 60 21.87 3 1961 227.10 155 208 33 22.39 1 1964 1,934.04 1,288 1,725 325 23.15 14 1971 44.00 28 38 9 24.78 1975 422.00 254 340 107 25.63 4 1980 425.11 241 323 128 26.60 5 1981 10,801.05 6,058 8,116 3,333 26.78 124 1982 5,594.45 3,098 4,150 1,780 26.96 66 1983 668.06 365 489 219 27.13 8 1984 649.22 350 469 219 27.30 8 1985 2,983.76 1,586 2,125 1,038 27.47 38 1987 25,778.43 13,302 17,820 9,505 27.79 342 1988 17,550.87 8,917 11,946 6,658 27.94 238 1989 9,057.84 4,527 6,065 3,537 28.09 126 1990 20,847.26 10,243 13,722 8,376 28.24 297 1992 20,625.27 9,772 13,091 8,772 28.52 308 1993 1,583.83 736 986 693 28.65 24 1994 29,314.94 13,347 17,880 13,193 28.78 458 1995 124,864.51 55,644 74,544 57,813 28.91 2,000 1996 15,621.60 6,806 9,118 7,441 29.03 256 1999 29,196.63 11,798 15,805 15,143 29.38 515 2000 1,832.30 720 965 978 29.48 33 2004 32,773.10 11,276 15,106 19,634 29.88 657 2007 7,623.69 2,308 3,092 4,989 30.14 166 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-96 Attachment C J. Spanos, Avista Page 576 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.00 MISCELLANEOUS POWER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 65-R1 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 2008 37,135.29 10,686 14,316 25,048 30.22 829 2009 104,268.85 28,384 38,025 72,500 30.30 2,393 2018 274,452.23 25,950 34,764 256,155 30.94 8,279 2019 21,493.91 1,490 1,996 20,787 31.01 670 811,545.53 241,051 321,442 538,796 17,878 SPOKANE UPPER FALLS INTERIM SURVIVOR CURVE.. IOWA 65-R1 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -6 1951 30.54 22 22 11 20.42 1 1953 26.00 19 19 9 21.12 1985 1,739.84 872 866 978 30.20 32 1992 27,945.19 12,352 12,269 17,353 31.57 550 1996 57,280.62 23,128 22,973 37,745 32.26 1,170 1998 17,157.07 6,577 6,533 11,654 32.57 358 1999 226.45 84 83 157 32.72 5 2000 44.11 16 16 31 32.86 1 104,449.82 43,070 42,781 67,936 2,117 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 65-R1 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1908 1,077.55 1,026 394 726 5.51 132 1926 77.00 66 25 55 11.25 5 1930 26.00 22 8 19 12.68 1 1932 130.00 107 41 94 13.41 7 1940 31.00 24 9 23 16.40 1 1948 433.12 316 121 329 19.35 17 1950 249.52 179 69 191 20.07 10 1951 105.53 75 29 81 20.42 4 1960 29.75 20 8 23 23.46 1 1965 310.00 194 75 248 25.02 10 1966 2,251.00 1,398 537 1,804 25.32 71 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-97 Attachment C J. Spanos, Avista Page 577 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.00 MISCELLANEOUS POWER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 65-R1 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1967 154.91 95 37 125 25.61 5 1971 200.10 118 45 163 26.75 6 1980 145.93 77 30 122 29.07 4 1981 430.03 224 86 361 29.30 12 1984 886.02 443 170 751 29.98 25 1987 120,496.60 57,364 22,050 103,266 30.61 3,374 1990 641.41 289 111 556 31.20 18 1994 3,523.88 1,463 562 3,102 31.93 97 1995 64,680.86 26,261 10,094 57,174 32.09 1,782 2000 1,832.30 650 250 1,656 32.86 50 2001 20,546.95 7,062 2,715 18,654 33.00 565 2006 556.42 157 60 518 33.64 15 2007 7,621.60 2,054 790 7,137 33.76 211 2009 7,075.78 1,707 656 6,703 33.98 197 2013 3,960.13 704 271 3,848 34.39 112 2015 128,019.74 18,151 6,977 126,163 34.59 3,647 2016 550,802.79 67,600 25,985 546,850 34.68 15,768 2019 2,533.31 152 58 2,576 34.94 74 2021 103,321.34 1,300 500 106,954 35.11 3,046 1,022,150.57 189,298 72,764 990,272 29,267 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 65-R1 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1906 336.40 323 312 38 4.92 8 1907 462.00 442 427 54 5.22 10 1911 250.90 235 227 34 6.41 5 1912 76.00 71 69 11 6.71 2 1913 86.00 80 77 12 7.01 2 1918 65.00 59 57 11 8.57 1 1922 15.00 13 13 3 9.88 1923 83.00 73 70 16 10.22 2 1925 16.00 14 14 3 10.90 1926 116.00 100 97 24 11.25 2 1927 127.00 109 105 27 11.60 2 1928 36.00 31 30 8 11.96 1 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-98 Attachment C J. Spanos, Avista Page 578 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.00 MISCELLANEOUS POWER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 65-R1 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1934 57.00 46 44 15 14.16 1 1936 44.00 35 34 12 14.90 1 1937 15.00 12 12 4 15.28 1938 206.00 163 157 57 15.65 4 1939 18.00 14 14 5 16.03 1940 529.00 411 397 153 16.40 9 1943 120.00 91 88 37 17.52 2 1945 64.00 48 46 20 18.26 1 1947 438.00 322 311 145 18.99 8 1948 544.01 397 383 183 19.35 9 1949 185.00 134 129 63 19.71 3 1951 202.63 144 139 72 20.42 4 1952 144.30 102 98 52 20.77 3 1953 50.00 35 34 18 21.12 1 1955 28.92 20 19 11 21.81 1 1957 236.00 159 153 92 22.48 4 1958 83.00 56 54 32 22.81 1 1959 312.00 207 200 125 23.14 5 1963 136.36 87 84 58 24.41 2 1977 1,004.95 553 534 511 28.34 18 1983 195.80 99 96 108 29.76 4 1984 823.71 411 397 460 29.98 15 1985 27,940.75 13,738 13,259 15,799 30.20 523 1986 1,761.62 852 822 1,010 30.41 33 1990 1,046.95 472 456 633 31.20 20 1991 1,684.25 745 719 1,033 31.39 33 1992 1,076.77 467 451 669 31.57 21 1993 29,009.16 12,319 11,890 18,280 31.75 576 1997 21,404.25 8,266 7,978 14,282 32.42 441 2000 1,832.29 650 627 1,278 32.86 39 2001 119,904.09 41,212 39,776 84,924 33.00 2,573 2006 710.29 201 194 545 33.64 16 2007 7,621.60 2,054 1,982 5,944 33.76 176 2016 298,276.47 36,608 35,332 274,875 34.68 7,926 2018 267,511.37 21,842 21,081 257,131 34.86 7,376 2021 22,453.06 283 273 23,078 35.11 657 809,339.90 144,805 139,759 701,955 20,541 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-99 Attachment C J. Spanos, Avista Page 579 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.00 MISCELLANEOUS POWER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 65-R1 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 1952 704,362.15 530,662 795,929 1953 41,263.00 30,766 46,627 1954 661.92 488 748 1955 720.90 526 815 1956 346.40 250 391 1959 312.97 219 354 1961 3,384.20 2,311 3,824 1966 2,480.00 1,594 2,802 1968 439.76 275 488 9 28.62 1971 370.00 223 396 22 29.87 1 1972 50.27 30 53 4 30.28 1973 1,197.44 701 1,245 108 30.68 4 1980 13,331.33 7,005 12,438 2,627 33.41 79 1982 437.88 222 394 101 34.14 3 1984 48,778.60 23,897 42,430 12,690 34.86 364 1986 90,583.25 42,715 75,842 26,517 35.55 746 1989 4,117.59 1,826 3,242 1,411 36.54 39 1990 5,655.13 2,453 4,355 2,035 36.86 55 1992 620.04 257 456 244 37.49 7 1993 73,819.87 29,815 52,938 30,479 37.79 807 1994 3,817.40 1,503 2,669 1,645 38.08 43 1995 215,894.58 82,764 146,951 97,010 38.37 2,528 1996 3,216.13 1,199 2,129 1,505 38.65 39 1998 103,124.44 36,207 64,287 52,243 39.20 1,333 1999 84,396.10 28,703 50,963 44,404 39.46 1,125 2000 462,934.84 152,237 270,303 252,813 39.71 6,366 2001 1,750.27 556 987 991 39.96 25 2002 4,077.10 1,246 2,212 2,395 40.21 60 2003 2,458.37 722 1,282 1,496 40.44 37 2004 2,195.91 618 1,097 1,384 40.67 34 2006 11,712.49 2,996 5,320 7,916 41.12 193 2009 230,651.31 49,680 88,209 172,427 41.74 4,131 2011 784,410.77 146,182 259,553 626,832 42.13 14,879 2012 57,184.89 9,794 17,390 47,229 42.32 1,116 2013 1,403,060.48 218,413 387,802 1,197,656 42.50 28,180 2014 1,022.46 143 254 901 42.68 21 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-100 Attachment C J. Spanos, Avista Page 580 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.00 MISCELLANEOUS POWER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 65-R1 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 2018 461,899.59 32,188 57,151 464,795 43.36 10,719 2019 389,407.00 19,797 35,150 404,879 43.52 9,303 2021 103,888.22 1,088 1,932 115,462 43.83 2,634 5,320,035.05 1,462,271 2,441,410 3,570,229 84,871 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 65-R1 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 1959 684,111.48 508,825 670,969 156,806 25.03 6,265 1960 23,859.23 17,529 23,115 5,755 25.51 226 1963 1,573.60 1,113 1,468 436 26.95 16 1964 277.31 194 256 80 27.44 3 1969 176.00 115 152 61 29.85 2 1972 54.47 34 45 21 31.28 1 1975 484.83 288 380 207 32.69 6 1977 112,144.07 64,434 84,967 50,728 33.62 1,509 1981 6,970.87 3,729 4,917 3,517 35.43 99 1983 2,383.21 1,227 1,618 1,266 36.31 35 1984 239.42 121 160 130 36.74 4 1985 4,723.91 2,336 3,080 2,636 37.16 71 1986 48,064.34 23,269 30,684 27,474 37.59 731 1990 12,547.96 5,544 7,311 7,872 39.22 201 1992 81,392.85 34,216 45,119 53,366 39.99 1,334 1993 133,090.01 54,481 71,842 89,197 40.37 2,209 1994 25,266.06 10,063 13,270 17,302 40.74 425 1995 4,524.32 1,751 2,309 3,165 41.11 77 1997 25,832.10 9,405 12,402 18,855 41.82 451 2000 1,862.17 612 807 1,446 42.83 34 2001 531,784.56 168,239 221,851 421,609 43.16 9,769 2004 11,481.39 3,202 4,222 9,670 44.08 219 2005 3,176.00 844 1,113 2,730 44.38 62 2006 107,789.26 27,241 35,922 94,503 44.66 2,116 2007 19,054.48 4,553 6,004 17,052 44.95 379 2008 31,060.39 7,000 9,231 28,352 45.22 627 2009 777,881.84 164,302 216,659 724,578 45.49 15,928 2013 229,014.12 34,619 45,651 231,456 46.51 4,976 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-101 Attachment C J. Spanos, Avista Page 581 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.00 MISCELLANEOUS POWER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 65-R1 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2017 242,578.95 20,596 27,159 266,361 47.44 5,615 2018 222,150.85 14,865 19,602 249,201 47.66 5,229 2021 7,762.28 77 102 9,291 48.30 192 3,353,312.33 1,184,824 1,562,384 2,495,124 58,811 12,003,345.35 3,382,351 4,722,209 8,834,953 227,413 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 38.8 1.89 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-102 Attachment C J. Spanos, Avista Page 582 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.10 MISCELLANEOUS POWER PLANT EQUIPMENT - FISH AND WILDLIFE CONSERVATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 1999 45,440.41 19,935 39,136 12,211 33.36 366 2003 608.03 224 440 247 36.38 7 2006 51,779.77 16,312 32,024 26,487 38.52 688 2008 12,692.29 3,536 6,942 7,400 39.85 186 2019 1,828.48 106 208 1,858 45.61 41 2021 5,086.83 61 120 5,628 46.36 121 117,435.81 40,174 78,870 53,833 1,409 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2000 342,820.43 153,306 278,821 135,992 34.61 3,929 2004 5,736.28 2,120 3,856 3,085 37.99 81 2010 7,423.31 1,853 3,370 5,612 42.87 131 355,980.02 157,279 286,047 144,689 4,141 473,415.83 197,453 364,916 198,522 5,550 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 35.8 1.17 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-103 Attachment C J. Spanos, Avista Page 583 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.15 MISCELLANEOUS POWER PLANT EQUIPMENT - FISH AND WILDLIFE CONSERVATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 2020 14,592.13 670 472 14,996 32.91 456 14,592.13 670 472 14,996 456 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 2020 16,925.06 678 330 17,272 37.21 464 16,925.06 678 330 17,272 464 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 2015 48,758.79 6,979 5,554 49,543 43.85 1,130 2019 145,819.46 8,465 6,737 158,039 45.61 3,465 2020 10,277.65 362 288 11,326 46.00 246 2021 41,851.76 505 402 46,891 46.36 1,011 246,707.66 16,311 12,982 265,798 5,852 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2013 127,950.99 24,002 8,999 145,822 45.13 3,231 2014 58,568.94 9,759 3,659 67,209 45.84 1,466 2015 7,833.08 1,140 427 9,051 46.53 195 2017 58,308.49 5,954 2,232 68,321 47.85 1,428 2018 194,397.88 15,588 5,844 229,377 48.47 4,732 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-104 Attachment C J. Spanos, Avista Page 584 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.15 MISCELLANEOUS POWER PLANT EQUIPMENT - FISH AND WILDLIFE CONSERVATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2019 77,172.28 4,458 1,671 91,707 49.07 1,869 2020 23,106.95 809 303 27,656 49.64 557 2021 31,291.24 374 140 37,722 50.18 752 578,629.85 62,084 23,277 676,865 14,230 856,854.70 79,743 37,061 974,931 21,002 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 46.4 2.45 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-105 Attachment C J. Spanos, Avista Page 585 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.20 MISCELLANEOUS POWER PLANT EQUIPMENT - RECREATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LONG LAKE INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2055 NET SALVAGE PERCENT.. -6 2021 25,697.14 406 223 27,016 33.01 818 25,697.14 406 223 27,016 818 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 2014 18,741.21 3,304 956 18,535 36.06 514 18,741.21 3,304 956 18,535 514 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 2003 19,260.49 7,104 17,870 3,895 36.38 107 2006 1,848.11 582 1,464 624 38.52 16 2017 7,908.06 803 2,020 6,916 44.78 154 2018 15,023.78 1,200 3,019 13,958 45.21 309 2021 5,267.89 64 161 5,792 46.36 125 49,308.33 9,753 24,533 31,185 711 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2006 17,558.56 5,794 4,446 16,800 39.66 424 2014 7,022.73 1,170 898 7,600 45.84 166 2015 10,432.94 1,518 1,165 11,459 46.53 246 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-106 Attachment C J. Spanos, Avista Page 586 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 335.20 MISCELLANEOUS POWER PLANT EQUIPMENT - RECREATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 2017 2,249.74 230 176 2,546 47.85 53 2018 2,698.52 216 166 3,099 48.47 64 2019 5,425.83 313 240 6,325 49.07 129 45,388.32 9,241 7,091 47,829 1,082 139,135.00 22,704 32,802 124,565 3,125 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 39.9 2.25 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-107 Attachment C J. Spanos, Avista Page 587 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 336.00 ROADS, RAILROADS AND BRIDGES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 MONROE STREET INTERIM SURVIVOR CURVE.. IOWA 60-S2.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -7 1992 45,566.19 23,318 13,365 35,391 30.85 1,147 1993 3,428.93 1,705 977 2,692 31.58 85 1994 1,453.32 702 402 1,153 32.30 36 50,448.44 25,725 14,745 39,235 1,268 SPOKANE UPPER FALLS INTERIM SURVIVOR CURVE.. IOWA 60-S2.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -6 2012 17,835.78 3,899 2,874 16,032 36.53 439 2013 490,406.56 97,510 71,877 447,954 36.77 12,183 508,242.34 101,409 74,751 463,986 12,622 NINE MILE INTERIM SURVIVOR CURVE.. IOWA 60-S2.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 1994 547,608.47 270,980 191,840 377,672 29.36 12,863 1995 46,886.34 22,576 15,983 32,779 29.88 1,097 1996 375.25 176 125 266 30.38 9 594,870.06 293,732 207,948 410,717 13,969 POST FALLS INTERIM SURVIVOR CURVE.. IOWA 60-S2.5 PROBABLE RETIREMENT YEAR.. 12-2060 NET SALVAGE PERCENT.. -4 2017 577,943.72 64,308 53,322 547,739 37.56 14,583 577,943.72 64,308 53,322 547,739 14,583 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-108 Attachment C J. Spanos, Avista Page 588 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 336.00 ROADS, RAILROADS AND BRIDGES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CABINET GORGE INTERIM SURVIVOR CURVE.. IOWA 60-S2.5 PROBABLE RETIREMENT YEAR.. 12-2072 NET SALVAGE PERCENT.. -13 1952 809,617.25 756,751 871,547 43,321 10.37 4,178 1958 10,987.00 9,876 11,374 1,041 12.27 85 1988 77,742.23 46,523 53,580 34,268 27.99 1,224 1989 2,336.56 1,365 1,572 1,068 28.70 37 1990 1,192.81 680 783 565 29.41 19 1992 347.06 188 217 176 30.85 6 1993 47,214.96 24,801 28,563 24,790 31.58 785 1999 112,055.41 48,234 55,551 71,072 35.90 1,980 2000 37,070.73 15,346 17,674 24,216 36.60 662 2014 160,141.39 25,872 29,797 151,163 44.96 3,362 2016 412,307.18 49,819 57,376 408,531 45.85 8,910 1,671,012.58 979,455 1,128,034 760,210 21,248 NOXON RAPIDS INTERIM SURVIVOR CURVE.. IOWA 60-S2.5 PROBABLE RETIREMENT YEAR.. 12-2079 NET SALVAGE PERCENT.. -21 1959 76,150.50 72,762 68,411 23,731 12.62 1,880 1960 5,440.00 5,159 4,850 1,732 12.97 134 1966 4,731.99 4,260 4,005 1,720 15.36 112 1998 76,277.46 35,834 33,691 58,605 36.24 1,617 2000 42,548.24 18,452 17,349 34,135 37.86 902 2001 9,679.50 4,021 3,781 7,932 38.66 205 2004 8,169.55 2,937 2,761 7,124 41.04 174 2012 21,192.75 4,319 4,061 21,583 46.86 461 2018 15,559.64 1,221 1,148 17,679 50.46 350 259,749.63 148,965 140,057 174,240 5,835 3,662,266.77 1,613,594 1,618,856 2,396,127 69,525 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 34.5 1.90 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-109 Attachment C J. Spanos, Avista Page 589 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 341.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 KETTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 55-R4 PROBABLE RETIREMENT YEAR.. 12-2038 NET SALVAGE PERCENT.. -1 2018 9,028.80 1,559 3,289 5,830 16.97 344 9,028.80 1,559 3,289 5,830 344 NORTHEAST TURBINE INTERIM SURVIVOR CURVE.. IOWA 55-R4 PROBABLE RETIREMENT YEAR.. 12-2035 NET SALVAGE PERCENT.. -7 1978 227,647.72 190,458 243,583 1979 11,442.23 9,493 12,243 1980 1,764.73 1,452 1,888 1982 3,159.88 2,557 3,381 1983 4,533.52 3,636 4,851 1993 8,131.11 5,895 8,700 1994 53.94 39 58 2008 108,546.42 57,119 116,145 2011 327,816.46 150,551 332,811 17,952 13.95 1,287 2012 57,929.34 25,084 55,451 6,533 13.96 468 751,025.35 446,284 779,112 24,485 1,755 BOULDER PARK INTERIM SURVIVOR CURVE.. IOWA 55-R4 PROBABLE RETIREMENT YEAR.. 12-2042 NET SALVAGE PERCENT.. -1 2002 691,794.86 341,342 379,855 318,858 20.29 15,715 2003 17,957.84 8,608 9,579 8,558 20.37 420 2009 58,646.66 22,248 24,758 34,475 20.73 1,663 2010 380,681.98 136,790 152,224 232,265 20.77 11,183 2011 11,933.67 4,038 4,494 7,559 20.80 363 2012 29,009.53 9,170 10,205 19,095 20.83 917 2016 61,872.17 13,014 14,482 48,009 20.91 2,296 2018 7,821.67 1,131 1,259 6,641 20.94 317 2019 14,173.57 1,526 1,698 12,617 20.95 602 1,273,891.95 537,867 598,553 688,078 33,476 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-110 Attachment C J. Spanos, Avista Page 590 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 341.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 RATHDRUM TURBINE INTERIM SURVIVOR CURVE.. IOWA 55-R4 PROBABLE RETIREMENT YEAR.. 12-2034 NET SALVAGE PERCENT.. -4 2004 6,598.74 3,950 3,777 3,085 12.87 240 2005 3,130,198.50 1,825,209 1,745,497 1,509,910 12.89 117,138 2009 68,964.19 35,212 33,674 38,049 12.94 2,940 2010 7,245.69 3,543 3,388 4,147 12.95 320 2013 296,925.01 122,255 116,916 191,886 12.97 14,795 2017 7,706.06 2,062 1,972 6,042 12.99 465 2018 12,146.32 2,681 2,564 10,068 12.99 775 2019 30,944.36 5,194 4,967 27,215 12.99 2,095 2021 23,773.06 916 876 23,848 12.99 1,836 3,584,501.93 2,001,022 1,913,632 1,814,250 140,604 COYOTE SPRINGS 2 INTERIM SURVIVOR CURVE.. IOWA 55-R4 PROBABLE RETIREMENT YEAR.. 12-2043 NET SALVAGE PERCENT.. -3 2003 7,114,562.21 3,398,946 3,690,657 3,637,342 21.27 171,008 2004 111,019.89 51,350 55,757 58,593 21.36 2,743 2005 4,026,021.44 1,799,090 1,953,495 2,193,307 21.44 102,300 2006 4,508.19 1,940 2,106 2,537 21.51 118 2007 39,307.83 16,249 17,644 22,844 21.57 1,059 2008 1,448.35 572 621 871 21.63 40 2010 24,315.19 8,660 9,403 15,641 21.72 720 2011 9,078.57 3,040 3,301 6,050 21.76 278 2013 2,083.36 601 653 1,493 21.83 68 2014 1,299.79 342 371 967 21.85 44 2015 24,454.28 5,762 6,257 18,931 21.88 865 2016 362.12 75 81 292 21.89 13 2017 115,096.45 20,200 21,934 96,616 21.91 4,410 2018 46,085.10 6,517 7,076 40,391 21.93 1,842 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-111 Attachment C J. Spanos, Avista Page 591 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 341.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COYOTE SPRINGS 2 INTERIM SURVIVOR CURVE.. IOWA 55-R4 PROBABLE RETIREMENT YEAR.. 12-2043 NET SALVAGE PERCENT.. -3 2019 331.54 35 38 303 21.94 14 2020 237,740.25 15,664 17,008 227,864 21.95 10,381 2021 210.65 5 5 212 21.96 10 11,757,925.21 5,329,048 5,786,408 6,324,255 295,913 17,376,373.24 8,315,780 9,080,994 8,856,898 472,092 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 18.8 2.72 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-112 Attachment C J. Spanos, Avista Page 592 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 342.00 FUEL HOLDERS, PRODUCERS AND ACCESSORIES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 KETTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2038 NET SALVAGE PERCENT.. -1 2002 89,232.19 48,485 70,508 19,617 16.30 1,203 89,232.19 48,485 70,508 19,617 1,203 NORTHEAST TURBINE INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2035 NET SALVAGE PERCENT.. -7 1979 5,604.48 4,587 5,997 1985 1,477.56 1,154 1,581 2001 20,225.21 12,903 21,641 2002 1,636.75 1,023 1,751 2019 7,952.84 1,291 5,542 2,967 13.92 213 36,896.84 20,958 36,512 2,967 213 BOULDER PARK INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2042 NET SALVAGE PERCENT.. -1 2002 10,329.70 5,095 2,416 8,017 19.80 405 2003 14.46 7 3 11 19.89 1 2016 52,314.47 11,013 5,223 47,615 20.66 2,305 2017 99,484.81 17,819 8,451 92,029 20.69 4,448 162,143.44 33,934 16,093 147,672 7,159 RATHDRUM TURBINE INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2034 NET SALVAGE PERCENT.. -4 2005 1,682,329.00 980,348 996,925 752,697 12.72 59,174 2010 13,479.40 6,583 6,694 7,324 12.83 571 1,695,808.40 986,931 1,003,620 760,021 59,745 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-113 Attachment C J. Spanos, Avista Page 593 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 342.00 FUEL HOLDERS, PRODUCERS AND ACCESSORIES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 LANCASTER INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2040 NET SALVAGE PERCENT.. -3 2010 91,977.92 35,947 45,642 49,095 18.53 2,649 91,977.92 35,947 45,642 49,095 2,649 COYOTE SPRINGS 2 INTERIM SURVIVOR CURVE.. IOWA 55-R3 PROBABLE RETIREMENT YEAR.. 12-2043 NET SALVAGE PERCENT.. -3 2003 12,266,683.72 5,860,219 6,773,245 5,861,439 20.75 282,479 2004 29,481.61 13,651 15,778 14,588 20.84 700 2005 6,547,090.97 2,929,917 3,386,400 3,357,104 20.93 160,397 2006 15,396.82 6,637 7,671 8,188 21.02 390 2011 11,213.07 3,767 4,354 7,196 21.36 337 2012 5,441.91 1,704 1,969 3,636 21.42 170 2013 5,068.37 1,467 1,696 3,525 21.47 164 2014 78,833.11 20,798 24,038 57,160 21.52 2,656 2015 16,336.06 3,865 4,467 12,359 21.56 573 2016 880.94 182 210 697 21.61 32 2017 3,832.23 673 778 3,169 21.65 146 2018 8,835.79 1,256 1,452 7,649 21.68 353 2019 806.55 85 98 733 21.71 34 2020 9,875.49 652 754 9,418 21.74 433 2021 512.46 12 14 514 21.77 24 19,000,289.10 8,844,885 10,222,924 9,347,373 448,888 21,076,347.89 9,971,140 11,395,299 10,326,745 519,857 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 19.9 2.47 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-114 Attachment C J. Spanos, Avista Page 594 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 343.00 PRIME MOVERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 KETTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 60-S2 PROBABLE RETIREMENT YEAR.. 12-2038 NET SALVAGE PERCENT.. -1 2002 8,670,084.38 4,742,062 6,454,410 2,302,376 16.34 140,904 8,670,084.38 4,742,062 6,454,410 2,302,376 140,904 NORTHEAST TURBINE INTERIM SURVIVOR CURVE.. IOWA 60-S2 PROBABLE RETIREMENT YEAR.. 12-2035 NET SALVAGE PERCENT.. -7 1978 5,930,603.94 4,864,903 6,345,746 1979 1,910.23 1,558 2,044 1980 142,521.74 115,557 152,498 1981 2,730.30 2,200 2,921 1982 128,743.22 103,068 137,755 1983 173.98 138 186 1988 31,407.95 24,008 33,607 1991 16,837.69 12,500 18,016 2001 302,216.79 193,832 288,006 35,366 13.56 2,608 2002 2,501,128.38 1,570,934 2,334,177 342,030 13.60 25,149 9,058,274.22 6,888,698 9,314,957 377,397 27,757 BOULDER PARK INTERIM SURVIVOR CURVE.. IOWA 60-S2 PROBABLE RETIREMENT YEAR.. 12-2042 NET SALVAGE PERCENT.. -1 2003 8,726.50 4,220 4,888 3,926 19.94 197 2004 28,341.82 13,287 15,389 13,236 20.04 660 2005 20,147.96 9,130 10,574 9,775 20.14 485 57,216.28 26,637 30,851 26,937 1,342 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-115 Attachment C J. Spanos, Avista Page 595 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 343.00 PRIME MOVERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 RATHDRUM TURBINE INTERIM SURVIVOR CURVE.. IOWA 60-S2 PROBABLE RETIREMENT YEAR.. 12-2034 NET SALVAGE PERCENT.. -4 1997 19,116.48 13,100 17,068 2,813 12.46 226 1998 1,436.86 970 1,264 230 12.50 18 1999 25,265.89 16,787 21,872 4,404 12.55 351 2000 45,230.18 29,544 38,494 8,546 12.59 679 2002 3,554,069.90 2,233,227 2,909,736 786,497 12.67 62,076 2003 13,208.72 8,119 10,578 3,159 12.71 249 3,658,328.03 2,301,747 2,999,013 805,648 63,599 21,443,902.91 13,959,144 18,799,230 3,512,358 233,602 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 15.0 1.09 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-116 Attachment C J. Spanos, Avista Page 596 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 344.00 GENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 KETTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 50-R1 PROBABLE RETIREMENT YEAR.. 12-2038 NET SALVAGE PERCENT.. -1 2018 225,595.60 37,580 57,801 170,050 16.05 10,595 2019 8,665.33 1,083 1,666 7,086 16.08 441 234,260.93 38,663 59,467 177,136 11,036 NORTHEAST TURBINE INTERIM SURVIVOR CURVE.. IOWA 50-R1 PROBABLE RETIREMENT YEAR.. 12-2035 NET SALVAGE PERCENT.. -7 1978 2,438,374.48 1,910,824 2,576,298 32,763 11.73 2,793 1979 18,464.60 14,382 19,391 366 11.81 31 1980 42,300.28 32,748 44,153 1,108 11.88 93 1981 22,277.70 17,138 23,107 731 11.95 61 1982 1,328.54 1,015 1,368 53 12.03 4 2007 15,889.20 8,356 11,266 5,735 13.15 436 2019 6,594.28 1,034 1,394 5,662 13.39 423 2021 311,438.34 11,277 15,204 318,035 13.42 23,699 2,856,667.42 1,996,774 2,692,182 364,453 27,540 BOULDER PARK INTERIM SURVIVOR CURVE.. IOWA 50-R1 PROBABLE RETIREMENT YEAR.. 12-2042 NET SALVAGE PERCENT.. -1 2002 29,065,094.71 13,541,512 17,786,955 11,568,791 18.65 620,311 2003 7,607.58 3,448 4,529 3,155 18.72 169 2004 342,193.26 150,481 197,659 147,956 18.79 7,874 2005 22,312.80 9,494 12,470 10,065 18.86 534 2010 517,511.28 177,238 232,804 289,882 19.14 15,145 2014 29,593.57 7,536 9,899 19,991 19.34 1,034 2016 482,211.43 97,007 127,420 359,614 19.42 18,518 2017 241,553.96 41,321 54,276 189,694 19.47 9,743 2018 87,855.84 12,166 15,980 72,754 19.51 3,729 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-117 Attachment C J. Spanos, Avista Page 597 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 344.00 GENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 BOULDER PARK INTERIM SURVIVOR CURVE.. IOWA 50-R1 PROBABLE RETIREMENT YEAR.. 12-2042 NET SALVAGE PERCENT.. -1 2019 170,333.77 17,544 23,044 148,993 19.55 7,621 2020 156,960.23 10,149 13,331 145,199 19.59 7,412 2021 247,230.63 5,596 7,350 242,353 19.63 12,346 31,370,459.06 14,073,492 18,485,718 13,198,446 704,436 RATHDRUM TURBINE INTERIM SURVIVOR CURVE.. IOWA 50-R1 PROBABLE RETIREMENT YEAR.. 12-2034 NET SALVAGE PERCENT.. -4 2000 585,435.40 366,834 382,341 226,512 12.10 18,720 2001 1,061.47 653 681 423 12.13 35 2005 47,935,155.94 26,974,723 28,114,985 21,737,578 12.23 1,777,398 2006 6,237.45 3,414 3,558 2,929 12.25 239 2007 54,222.91 28,781 29,998 26,394 12.27 2,151 2008 223,370.38 114,573 119,416 112,889 12.29 9,185 2013 115,105.84 45,905 47,845 71,865 12.38 5,805 2016 651,532.12 195,479 203,742 473,851 12.43 38,122 2017 12,982.34 3,369 3,511 9,990 12.45 802 2018 129,825.79 27,795 28,970 106,049 12.46 8,511 2020 784,951.45 82,280 85,758 730,591 12.49 58,494 2021 702,591.34 25,918 27,014 703,681 12.51 56,249 51,202,472.43 27,869,724 29,047,819 24,202,753 1,975,711 LANCASTER INTERIM SURVIVOR CURVE.. IOWA 50-R1 PROBABLE RETIREMENT YEAR.. 12-2040 NET SALVAGE PERCENT.. -3 2010 208,505.82 77,746 98,908 115,853 17.50 6,620 208,505.82 77,746 98,908 115,853 6,620 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-118 Attachment C J. Spanos, Avista Page 598 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 344.00 GENERATORS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COYOTE SPRINGS 2 INTERIM SURVIVOR CURVE.. IOWA 50-R1 PROBABLE RETIREMENT YEAR.. 12-2043 NET SALVAGE PERCENT.. -3 2003 67,129,398.34 30,237,739 31,107,428 38,035,852 19.48 1,952,559 2004 177,400.49 77,533 79,763 102,960 19.55 5,266 2005 36,062,623.24 15,235,189 15,673,379 21,471,123 19.63 1,093,791 2006 220,957.85 90,015 92,604 134,983 19.70 6,852 2007 6,019.39 2,357 2,425 3,775 19.76 191 2008 796,520.96 298,476 307,061 513,356 19.83 25,888 2009 805,927.38 287,698 295,973 534,133 19.89 26,854 2010 64,534.72 21,836 22,464 44,007 19.95 2,206 2011 13,298.40 4,238 4,360 9,337 20.00 467 2012 4,070,486.81 1,210,194 1,245,001 2,947,600 20.06 146,939 2013 465,962.36 128,077 131,761 348,181 20.11 17,314 2014 197,991.82 49,663 51,091 152,840 20.16 7,581 2015 469,395.56 105,630 108,668 374,809 20.21 18,546 2016 23,492,380.45 4,634,722 4,768,025 19,429,127 20.26 958,989 2017 652,531.38 109,197 112,338 559,770 20.31 27,561 2018 717,693.68 97,452 100,255 638,970 20.35 31,399 2019 1,795,250.52 180,732 185,930 1,663,178 20.40 81,528 2020 687,321.73 43,248 44,492 663,449 20.44 32,458 2021 16,090,159.28 356,317 366,565 16,206,299 20.48 791,323 153,915,854.36 53,170,313 54,699,583 103,833,747 5,227,712 239,788,220.02 97,226,712 105,083,676 141,892,388 7,953,055 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 17.8 3.32 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-119 Attachment C J. Spanos, Avista Page 599 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 344.01 GENERATORS - SOLAR CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CENTRAL OPERATIONS FACILITY INTERIM SURVIVOR CURVE.. IOWA 25-S2.5 PROBABLE RETIREMENT YEAR.. 12-2029 NET SALVAGE PERCENT.. -3 2009 63,328.00 40,872 38,468 26,760 7.24 3,696 2012 86,341.82 49,174 46,282 42,651 7.60 5,612 2015 299,502.41 139,692 131,475 177,012 7.83 22,607 449,172.23 229,738 216,225 246,423 31,915 BOULDER PARK INTERIM SURVIVOR CURVE.. IOWA 25-S2.5 PROBABLE RETIREMENT YEAR.. 12-2042 NET SALVAGE PERCENT.. -1 2016 22,481.62 5,441 1,845 20,861 17.39 1,200 22,481.62 5,441 1,845 20,861 1,200 471,653.85 235,179 218,070 267,284 33,115 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 8.1 7.02 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-120 Attachment C J. Spanos, Avista Page 600 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 345.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 KETTLE FALLS INTERIM SURVIVOR CURVE.. IOWA 30-S0.5 PROBABLE RETIREMENT YEAR.. 12-2038 NET SALVAGE PERCENT.. -1 2012 6,036.30 2,275 1,446 4,651 14.23 327 2016 7,345.81 1,899 1,207 6,213 14.97 415 2021 525,140.53 15,896 10,101 520,291 15.86 32,805 538,522.64 20,070 12,753 531,155 33,547 NORTHEAST TURBINE INTERIM SURVIVOR CURVE.. IOWA 30-S0.5 PROBABLE RETIREMENT YEAR.. 12-2035 NET SALVAGE PERCENT.. -7 2007 91,646.91 50,616 98,062 2009 22,566.50 11,584 24,146 2010 1,052,736.92 517,064 1,123,628 2,801 11.95 234 2012 67,910.52 30,009 65,212 7,452 12.21 610 2015 5,254.60 1,830 3,977 1,646 12.60 131 2019 2,945.08 493 1,071 2,080 13.10 159 1,243,060.53 611,596 1,316,097 13,978 1,134 BOULDER PARK INTERIM SURVIVOR CURVE.. IOWA 30-S0.5 PROBABLE RETIREMENT YEAR.. 12-2042 NET SALVAGE PERCENT.. -1 2003 2,043.27 1,038 1,056 1,007 14.01 72 2007 30,585.71 13,544 13,782 17,109 15.14 1,130 2009 79,044.80 31,995 32,558 47,277 15.70 3,011 2010 32,221.62 12,371 12,589 19,955 15.98 1,249 2012 102,172.20 34,619 35,228 67,966 16.52 4,114 2013 380,689.44 119,486 121,589 262,907 16.79 15,659 2014 3,086.02 886 902 2,215 17.06 130 2019 15,488.88 1,813 1,845 13,799 18.39 750 2020 5,786.10 424 431 5,412 18.66 290 2021 273,685.32 6,977 7,100 269,322 18.92 14,235 924,803.36 223,153 227,080 706,971 40,640 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-121 Attachment C J. Spanos, Avista Page 601 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 345.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 RATHDRUM TURBINE INTERIM SURVIVOR CURVE.. IOWA 30-S0.5 PROBABLE RETIREMENT YEAR.. 12-2034 NET SALVAGE PERCENT.. -4 2005 662,579.83 387,823 309,217 379,866 10.65 35,668 2008 1,050,367.00 562,074 448,150 644,231 11.02 58,460 2010 40,149.20 19,866 15,839 25,916 11.25 2,304 2013 674,160.73 282,113 224,933 476,194 11.60 41,051 2015 159,097.79 56,292 44,882 120,579 11.83 10,193 2016 87,452.35 27,630 22,030 68,921 11.94 5,772 2017 442,119.63 121,209 96,642 363,163 12.04 30,163 2018 15,473.55 3,502 2,792 13,300 12.15 1,095 2019 323,167.14 55,788 44,481 291,613 12.26 23,786 2021 1,353,502.43 53,223 42,436 1,365,207 12.47 109,479 4,808,069.65 1,569,520 1,251,402 3,748,990 317,971 LANCASTER INTERIM SURVIVOR CURVE.. IOWA 30-S0.5 PROBABLE RETIREMENT YEAR.. 12-2040 NET SALVAGE PERCENT.. -3 2014 49,439.02 15,277 15,300 35,622 15.89 2,242 2021 258,641.36 7,430 7,441 258,959 17.43 14,857 308,080.38 22,707 22,741 294,581 17,099 COYOTE SPRINGS 2 INTERIM SURVIVOR CURVE.. IOWA 30-S0.5 PROBABLE RETIREMENT YEAR.. 12-2043 NET SALVAGE PERCENT.. -3 2003 7,173,050.29 3,666,858 5,538,476 1,849,766 14.32 129,174 2004 19,282.23 9,550 14,424 5,436 14.63 372 2005 4,032,864.82 1,930,336 2,915,608 1,238,243 14.94 82,881 2006 80,632.85 37,226 56,227 26,825 15.24 1,760 2008 99,548.64 42,292 63,878 38,657 15.84 2,440 2009 98,927.65 40,045 60,485 41,411 16.14 2,566 2010 1,668.26 641 968 750 16.43 46 2011 417,459.60 150,946 227,991 201,992 16.73 12,074 2012 156,239.26 52,795 79,742 81,184 17.02 4,770 2013 4,702,774.93 1,469,142 2,219,014 2,624,845 17.32 151,550 2014 132,016.93 37,678 56,909 79,068 17.61 4,490 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-122 Attachment C J. Spanos, Avista Page 602 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 345.00 ACCESSORY ELECTRIC EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COYOTE SPRINGS 2 INTERIM SURVIVOR CURVE.. IOWA 30-S0.5 PROBABLE RETIREMENT YEAR.. 12-2043 NET SALVAGE PERCENT.. -3 2015 137.16 35 53 88 17.90 5 2016 13,162.39 2,964 4,477 9,080 18.19 499 2017 17,986.40 3,444 5,202 13,324 18.48 721 2018 938.80 145 219 748 18.77 40 2019 157,553.96 18,224 27,526 134,755 19.05 7,074 2020 1,049.30 76 115 966 19.34 50 2021 781,078.54 19,992 30,196 774,315 19.62 39,466 17,886,372.01 7,482,389 11,301,510 7,121,453 439,978 25,708,908.57 9,929,435 14,131,584 12,417,128 850,369 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 14.6 3.31 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-123 Attachment C J. Spanos, Avista Page 603 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 345.01 ACCESSORY ELECTRIC EQUIPMENT - SOLAR CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 CENTRAL OPERATIONS FACILITY INTERIM SURVIVOR CURVE.. IOWA 25-S2.5 PROBABLE RETIREMENT YEAR.. 12-2029 NET SALVAGE PERCENT.. -3 2012 33,209.41 18,914 11,701 22,505 7.60 2,961 33,209.41 18,914 11,701 22,505 2,961 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 7.6 8.92 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-124 Attachment C J. Spanos, Avista Page 604 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 346.00 MISCELLANEOUS POWER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 NORTHEAST TURBINE INTERIM SURVIVOR CURVE.. IOWA 35-R2 PROBABLE RETIREMENT YEAR.. 12-2035 NET SALVAGE PERCENT.. -7 1978 97,004.94 85,714 103,795 1979 23,774.76 20,794 25,439 1980 5,916.90 5,121 6,331 1982 31,356.79 26,564 33,552 1993 14,533.18 10,710 15,551 2005 6,732.14 3,903 7,203 2007 75,264.12 40,925 80,533 2011 1,896.00 867 2,006 22 12.99 2 2012 142,518.61 61,402 142,084 10,411 13.07 797 398,997.44 256,000 416,493 10,434 799 BOULDER PARK INTERIM SURVIVOR CURVE.. IOWA 35-R2 PROBABLE RETIREMENT YEAR.. 12-2042 NET SALVAGE PERCENT.. -1 2005 3,112.59 1,442 1,436 1,708 16.80 102 2013 13,584.50 4,020 4,003 9,717 18.65 521 2020 47,955.33 3,243 3,229 45,206 19.65 2,301 64,652.42 8,705 8,668 56,631 2,924 RATHDRUM TURBINE INTERIM SURVIVOR CURVE.. IOWA 35-R2 PROBABLE RETIREMENT YEAR.. 12-2034 NET SALVAGE PERCENT.. -4 2015 249,472.21 85,969 75,249 184,202 12.39 14,867 249,472.21 85,969 75,249 184,202 14,867 COYOTE SPRINGS 2 INTERIM SURVIVOR CURVE.. IOWA 35-R2 PROBABLE RETIREMENT YEAR.. 12-2043 NET SALVAGE PERCENT.. -3 2003 262,803.38 131,235 77,409 193,278 16.63 11,622 2004 1,527.68 736 434 1,139 16.97 67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-125 Attachment C J. Spanos, Avista Page 605 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 346.00 MISCELLANEOUS POWER PLANT EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 COYOTE SPRINGS 2 INTERIM SURVIVOR CURVE.. IOWA 35-R2 PROBABLE RETIREMENT YEAR.. 12-2043 NET SALVAGE PERCENT.. -3 2005 310,522.26 144,068 84,979 234,859 17.30 13,576 2006 30,924.38 13,775 8,125 23,727 17.61 1,347 2007 10,692.58 4,560 2,690 8,324 17.90 465 2008 23,236.73 9,449 5,574 18,360 18.18 1,010 2009 45,317.08 17,500 10,322 36,354 18.44 1,971 2010 188,003.89 68,542 40,430 153,214 18.69 8,198 2011 44,932.27 15,372 9,067 37,213 18.92 1,967 2013 2,546.01 747 441 2,182 19.35 113 2014 1,588.47 424 250 1,386 19.54 71 2015 648.41 155 91 576 19.72 29 2016 442.52 93 55 401 19.89 20 2017 1,925.06 341 201 1,782 20.05 89 2018 4,438.51 635 375 4,197 20.20 208 2019 405.16 43 25 392 20.34 19 2020 4,960.79 329 194 4,916 20.47 240 2021 257.44 6 4 262 20.59 13 935,172.62 408,010 240,666 722,562 41,025 1,648,294.69 758,684 741,077 973,829 59,615 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 16.3 3.62 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-126 Attachment C J. Spanos, Avista Page 606 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 350.30 REMOVING PROPERTY OF OTHERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 80-R4 NET SALVAGE PERCENT.. 0 1906 2.15 2 2 1907 14.85 15 15 1910 2,774.02 2,698 2,774 1911 2,558.29 2,480 2,558 1914 130.23 125 130 1915 16.03 15 16 1918 92.21 87 92 1919 5,640.19 5,330 5,640 1920 1,045.97 985 1,046 1923 6,098.20 5,683 6,098 1924 949.84 882 950 1925 14,022.91 12,973 14,023 1926 5,304.58 4,889 5,305 1927 2,690.90 2,471 2,691 1928 2,116.82 1,936 2,117 1929 4,951.17 4,510 4,951 1930 5,815.68 5,276 5,816 1931 337.68 305 338 1932 63.40 57 63 1933 50.64 45 50 1 8.38 1934 76.47 68 76 1935 681.45 604 674 7 9.06 1 1936 6,444.57 5,685 6,341 104 9.43 11 1937 5,028.83 4,413 4,923 106 9.80 11 1938 380.89 332 370 11 10.20 1 1939 45.29 39 44 1 10.60 1940 1,909.37 1,646 1,836 73 11.03 7 1941 456.48 391 436 20 11.48 2 1943 462.27 390 435 27 12.43 2 1947 3,937.71 3,220 3,592 346 14.58 24 1948 771.63 625 697 75 15.16 5 1949 264.32 212 236 28 15.77 2 1952 18,784.64 14,635 16,325 2,460 17.67 139 1953 2,299.62 1,773 1,978 322 18.33 18 1954 43,549.20 33,201 37,035 6,514 19.01 343 1955 35,733.83 26,943 30,054 5,680 19.68 289 1957 11,374.93 8,379 9,347 2,028 21.07 96 1958 32,406.08 23,584 26,307 6,099 21.78 280 1959 13,016.34 9,357 10,437 2,579 22.49 115 1962 51,003.97 35,263 39,335 11,669 24.69 473 1964 206.00 139 155 51 26.20 2 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-127 Attachment C J. Spanos, Avista Page 607 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 350.30 REMOVING PROPERTY OF OTHERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 80-R4 NET SALVAGE PERCENT.. 0 1965 7,360.15 4,879 5,442 1,918 26.97 71 1966 16,737.08 10,931 12,193 4,544 27.75 164 1967 735.05 473 528 207 28.54 7 1968 11,134.89 7,051 7,865 3,270 29.34 111 1969 7,993.56 4,981 5,556 2,438 30.15 81 1970 4,576.23 2,805 3,129 1,447 30.97 47 1971 16,862.51 10,162 11,335 5,528 31.79 174 1972 17,061.87 10,103 11,270 5,792 32.63 178 1973 1,984.29 1,154 1,287 697 33.47 21 1974 33,925.51 19,371 21,608 12,318 34.32 359 1975 36,626.03 20,520 22,889 13,737 35.18 390 1976 21,602.55 11,868 13,238 8,365 36.05 232 1977 35,888.73 19,322 21,553 14,336 36.93 388 1978 17,888.33 9,434 10,523 7,365 37.81 195 1979 13,472.13 6,955 7,758 5,714 38.70 148 1980 20,880.21 10,545 11,763 9,117 39.60 230 1981 10,236.36 5,053 5,636 4,600 40.51 114 1982 21,905.35 10,564 11,784 10,121 41.42 244 1983 21,335.75 10,044 11,204 10,132 42.34 239 1984 60,288.79 27,688 30,885 29,404 43.26 680 1985 17,613.14 7,884 8,794 8,819 44.19 200 1987 51,235.99 21,737 24,247 26,989 46.06 586 1988 281,177.01 115,952 129,342 151,835 47.01 3,230 1989 4,362.46 1,747 1,949 2,413 47.96 50 1990 54,586.30 21,213 23,663 30,923 48.91 632 1991 9,961.16 3,752 4,185 5,776 49.87 116 1992 10,164.56 3,706 4,134 6,031 50.83 119 1993 4,314.27 1,521 1,697 2,617 51.79 51 1994 128,882.33 43,884 48,952 79,930 52.76 1,515 1995 121,628.95 39,941 44,553 77,076 53.73 1,435 1997 56,093.20 17,052 19,021 37,072 55.68 666 1998 9,230.56 2,693 3,004 6,227 56.66 110 1999 44,462.04 12,427 13,862 30,600 57.64 531 2000 5,837.75 1,560 1,740 4,098 58.62 70 2001 679.40 173 193 486 59.61 8 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-128 Attachment C J. Spanos, Avista Page 608 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 350.30 REMOVING PROPERTY OF OTHERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 80-R4 NET SALVAGE PERCENT.. 0 2002 1,240.52 301 336 905 60.59 15 2003 22,529.43 5,187 5,786 16,743 61.58 272 2007 1,561.82 282 314 1,248 65.54 19 1,487,565.91 726,578 808,526 679,040 15,519 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 43.8 1.04 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-129 Attachment C J. Spanos, Avista Page 609 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 350.40 LAND RIGHTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 80-R4 NET SALVAGE PERCENT.. 0 1906 11.99 12 12 1907 85.15 83 85 1910 15,906.75 15,469 15,907 1911 14,669.70 14,222 14,670 1914 746.77 717 747 1915 91.96 88 92 1918 528.79 501 529 1919 32,341.81 30,563 32,342 1920 5,997.78 5,648 5,998 1923 34,942.54 32,562 34,943 1924 5,606.13 5,205 5,603 3 5.72 1 1925 80,409.76 74,389 80,079 331 5.99 55 1926 30,417.41 28,033 30,177 240 6.27 38 1927 15,430.09 14,167 15,251 179 6.55 27 1928 12,138.19 11,100 11,949 189 6.84 28 1929 28,390.83 25,861 27,839 552 7.13 77 1930 33,348.08 30,251 32,565 783 7.43 105 1931 1,936.32 1,749 1,883 53 7.74 7 1932 363.59 327 352 12 8.05 1 1933 290.37 260 280 10 8.38 1 1934 438.52 391 421 18 8.71 2 1935 3,907.55 3,465 3,730 178 9.06 20 1936 36,954.28 32,598 35,091 1,863 9.43 198 1937 28,836.17 25,304 27,240 1,596 9.80 163 1938 2,184.10 1,906 2,052 132 10.20 13 1939 259.71 225 242 18 10.60 2 1940 10,948.64 9,439 10,161 788 11.03 71 1941 2,617.53 2,242 2,413 205 11.48 18 1943 2,650.74 2,239 2,410 241 12.43 19 1947 22,579.50 18,464 19,876 2,704 14.58 185 1948 12,704.46 10,297 11,085 1,619 15.16 107 1949 1,515.67 1,217 1,310 206 15.77 13 1950 53,927.00 42,878 46,158 7,769 16.39 474 1951 1,459.00 1,149 1,237 222 17.02 13 1952 107,107.36 83,449 89,832 17,275 17.67 978 1953 13,186.38 10,165 10,943 2,243 18.33 122 1954 22,937.81 17,487 18,825 4,113 19.01 216 1955 4,033.00 3,041 3,274 759 19.68 39 1956 3,381.00 2,520 2,713 668 20.37 33 1957 417,639.07 307,641 331,173 86,466 21.07 4,104 1958 23,069.92 16,789 18,073 4,997 21.78 229 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-130 Attachment C J. Spanos, Avista Page 610 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 350.40 LAND RIGHTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 80-R4 NET SALVAGE PERCENT.. 0 1959 262,967.62 189,042 203,502 59,466 22.49 2,644 1960 109,455.00 77,700 83,643 25,812 23.21 1,112 1961 3,773.00 2,643 2,845 928 23.95 39 1962 44,858.03 31,014 33,386 11,472 24.69 465 1963 97,660.00 66,604 71,699 25,961 25.44 1,020 1964 2,814.00 1,892 2,037 777 26.20 30 1965 165,640.53 109,800 118,199 47,442 26.97 1,759 1966 104,825.28 68,463 73,700 31,125 27.75 1,122 1967 4,214.94 2,711 2,918 1,297 28.54 45 1968 62,918.56 39,843 42,891 20,028 29.34 683 1969 45,836.44 28,562 30,747 15,089 30.15 500 1970 26,240.84 16,082 17,312 8,929 30.97 288 1971 96,692.50 58,269 62,726 33,966 31.79 1,068 1972 97,835.69 57,930 62,361 35,475 32.63 1,087 1973 47,839.66 27,825 29,953 17,887 33.47 534 1974 194,534.69 111,079 119,575 74,960 34.32 2,184 1975 210,019.88 117,664 126,664 83,356 35.18 2,369 1976 123,872.74 68,053 73,258 50,615 36.05 1,404 1977 205,792.10 110,794 119,269 86,523 36.93 2,343 1978 102,574.70 54,096 58,234 44,341 37.81 1,173 1979 77,251.47 39,881 42,932 34,319 38.70 887 1980 119,730.64 60,464 65,089 54,642 39.60 1,380 1981 58,697.05 28,974 31,190 27,507 40.51 679 1982 224,186.32 108,114 116,384 107,802 41.42 2,603 1983 346,052.05 162,904 175,365 170,687 42.34 4,031 1984 712,165.49 327,062 352,079 360,086 43.26 8,324 1985 378,399.44 169,379 182,335 196,064 44.19 4,437 1986 38,908.11 16,964 18,262 20,646 45.12 458 1987 505,756.93 214,567 230,979 274,778 46.06 5,966 1988 139,326.63 57,456 61,851 77,476 47.01 1,648 1989 25,015.11 10,019 10,785 14,230 47.96 297 1990 313,007.19 121,641 130,945 182,062 48.91 3,722 1991 57,118.97 21,512 23,157 33,962 49.87 681 1992 54,540.71 19,887 21,408 33,133 50.83 652 1993 24,738.80 8,723 9,390 15,349 51.79 296 1994 452,871.12 154,203 165,998 286,873 52.76 5,437 1995 697,902.22 229,177 246,707 451,195 53.73 8,397 1997 321,647.97 97,781 105,260 216,388 55.68 3,886 1998 52,929.61 15,442 16,623 36,307 56.66 641 1999 254,952.93 71,259 76,710 178,243 57.64 3,092 2000 51,029.04 13,638 14,681 36,348 58.62 620 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-131 Attachment C J. Spanos, Avista Page 611 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 350.40 LAND RIGHTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 80-R4 NET SALVAGE PERCENT.. 0 2001 3,895.85 993 1,069 2,827 59.61 47 2002 7,113.37 1,726 1,858 5,255 60.59 87 2003 388,721.17 89,503 96,349 292,372 61.58 4,748 2004 41,067.49 8,948 9,632 31,435 62.57 502 2005 3,809.37 783 843 2,966 63.56 47 2006 1,439,264.77 277,951 299,212 1,140,053 64.55 17,662 2007 570,206.67 103,065 110,949 459,258 65.54 7,007 2008 1,575,350.78 265,053 285,327 1,290,024 66.54 19,387 2009 201,155.58 31,356 33,754 167,402 67.53 2,479 2010 2,967,244.98 425,444 457,987 2,509,258 68.53 36,615 2011 104,800.71 13,729 14,779 90,022 69.52 1,295 2012 55,409.37 6,566 7,068 48,341 70.52 685 2013 136,115.50 14,445 15,550 120,566 71.51 1,686 2014 237,943.54 22,276 23,980 213,964 72.51 2,951 2015 859,406.60 69,715 75,048 784,359 73.51 10,670 2016 3,275,446.08 224,761 241,953 3,033,493 74.51 40,713 2017 78,437.16 4,402 4,739 73,698 75.51 976 2018 239,121.70 10,462 11,262 227,860 76.50 2,979 2019 907,540.21 28,361 30,530 877,010 77.50 11,316 2020 215,775.38 4,046 4,356 211,419 78.50 2,693 2021 59,754.65 373 401 59,353 79.50 747 21,370,166.35 5,677,184 6,109,257 15,260,909 252,654 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 60.4 1.18 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-132 Attachment C J. Spanos, Avista Page 612 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 352.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-S2 NET SALVAGE PERCENT.. -15 1939 4,294.86 4,139 4,183 756 10.53 72 1940 20,471.81 19,624 19,830 3,713 10.82 343 1942 887.44 841 850 171 11.42 15 1945 151.54 141 142 32 12.37 3 1948 36,532.07 33,377 33,728 8,284 13.36 620 1949 1,761.57 1,599 1,616 410 13.70 30 1950 197.93 178 180 48 14.05 3 1951 4,517.85 4,045 4,088 1,108 14.40 77 1952 86,408.47 76,805 77,613 21,757 14.76 1,474 1953 793.14 700 707 205 15.13 14 1954 1,284.94 1,125 1,137 341 15.51 22 1955 6,396.85 5,558 5,616 1,740 15.89 110 1956 3,354.32 2,891 2,921 936 16.28 57 1957 2,277.61 1,948 1,968 651 16.67 39 1958 8,236.55 6,983 7,056 2,416 17.08 141 1959 5,370.12 4,514 4,561 1,615 17.49 92 1960 1,157.29 964 974 357 17.91 20 1962 1,414.30 1,157 1,169 457 18.77 24 1963 641.03 519 524 213 19.22 11 1965 1,218.07 967 977 424 20.14 21 1966 7,203.52 5,657 5,716 2,568 20.61 125 1968 5,674.93 4,359 4,405 2,121 21.59 98 1969 5,753.20 4,367 4,413 2,203 22.10 100 1970 6,193.76 4,645 4,694 2,429 22.61 107 1971 4,472.98 3,313 3,348 1,796 23.14 78 1972 64,608.77 47,232 47,729 26,571 23.68 1,122 1973 48,069.02 34,673 35,038 20,241 24.23 835 1975 127,528.40 89,439 90,380 56,278 25.36 2,219 1976 61,921.49 42,791 43,241 27,969 25.94 1,078 1977 88,593.23 60,283 60,917 40,965 26.54 1,544 1978 1,632.97 1,094 1,106 772 27.15 28 1980 113,764.29 73,646 74,420 56,409 28.41 1,986 1981 30,793.06 19,580 19,786 15,626 29.06 538 1982 20,327.66 12,688 12,821 10,556 29.72 355 1983 518,667.61 317,506 320,845 275,623 30.40 9,067 1984 1,836.73 1,102 1,114 998 31.09 32 1985 1,009,240.88 592,813 599,047 561,580 31.80 17,660 1986 1,353,584.76 777,829 786,009 770,613 32.52 23,697 1987 183,698.00 103,188 104,273 106,980 33.25 3,217 1989 1,410.40 755 763 859 34.75 25 1990 133,951.85 69,841 70,575 83,470 35.53 2,349 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-133 Attachment C J. Spanos, Avista Page 613 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 352.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-S2 NET SALVAGE PERCENT.. -15 1991 397,772.03 201,835 203,958 253,480 36.32 6,979 1993 670,518.93 321,015 324,391 446,706 37.94 11,774 1994 65,066.28 30,195 30,513 44,313 38.77 1,143 1995 67,624.09 30,378 30,697 47,071 39.61 1,188 1996 772,578.24 335,289 338,815 549,650 40.47 13,582 1997 485,192.11 203,185 205,322 352,649 41.33 8,533 1998 5,089.37 2,052 2,074 3,779 42.21 90 1999 365,612.21 141,596 143,085 277,369 43.11 6,434 2000 1,044,156.22 387,756 391,834 808,946 44.01 18,381 2001 112,188.33 39,836 40,255 88,762 44.93 1,976 2002 261,791.00 88,698 89,631 211,429 45.85 4,611 2003 71,697.51 23,099 23,342 59,110 46.79 1,263 2004 1,888,891.32 577,138 583,207 1,589,018 47.73 33,292 2005 2,136,912.85 617,016 623,504 1,833,946 48.68 37,674 2006 762,633.81 207,251 209,430 667,599 49.64 13,449 2007 1,404,913.42 357,673 361,434 1,254,216 50.61 24,782 2008 525,918.81 124,868 126,181 478,626 51.58 9,279 2009 281,900.01 62,043 62,695 261,490 52.56 4,975 2010 765,540.42 155,218 156,850 723,521 53.54 13,514 2011 178,954.28 33,150 33,499 172,298 54.53 3,160 2012 1,164,836.83 195,375 197,430 1,142,132 55.52 20,572 2013 2,055,977.75 308,835 312,083 2,052,291 56.51 36,317 2014 2,659,533.23 352,427 356,133 2,702,330 57.51 46,989 2015 403,083.80 46,355 46,842 416,704 58.50 7,123 2016 1,280,875.71 124,646 125,957 1,347,050 59.50 22,639 2017 721,069.89 57,408 58,012 771,218 60.50 12,747 2018 1,716,086.69 106,273 107,390 1,866,110 61.50 30,343 2019 351,120.74 15,530 15,693 388,096 62.50 6,210 2020 2,675,076.82 71,002 71,749 3,004,589 63.50 47,316 2021 1,689,280.61 14,939 15,096 1,927,576 64.50 29,885 30,958,188.58 7,666,957 7,747,582 27,854,334 545,668 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 51.0 1.76 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-134 Attachment C J. Spanos, Avista Page 614 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 353.00 STATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 46-R2 NET SALVAGE PERCENT.. -10 1930 2,802.32 3,083 3,083 1936 7,387.08 8,121 8,126 1950 1,347.75 1,360 1,423 60 3.80 16 1951 6,942.82 6,958 7,282 355 4.09 87 1952 274,094.27 272,795 285,510 15,994 4.38 3,652 1954 2,535.43 2,488 2,604 185 4.96 37 1955 193,475.96 188,487 197,272 15,552 5.26 2,957 1956 33,637.49 32,537 34,054 2,947 5.55 531 1957 104,356.11 100,194 104,864 9,928 5.85 1,697 1958 24,244.37 23,103 24,180 2,489 6.15 405 1959 235,729.99 222,944 233,336 25,967 6.45 4,026 1960 94,917.75 89,066 93,217 11,193 6.76 1,656 1962 22,807.65 21,052 22,033 3,055 7.40 413 1963 56,911.23 52,083 54,511 8,091 7.73 1,047 1964 146,370.58 132,762 138,950 22,058 8.07 2,733 1965 99,313.27 89,271 93,432 15,813 8.41 1,880 1966 110,421.72 98,307 102,889 18,575 8.77 2,118 1967 38,147.58 33,624 35,191 6,771 9.14 741 1968 255,183.48 222,670 233,049 47,653 9.51 5,011 1969 110,735.82 95,594 100,050 21,759 9.90 2,198 1970 31,377.82 26,787 28,036 6,480 10.30 629 1971 164,101.07 138,483 144,938 35,573 10.71 3,321 1972 251,497.94 209,652 219,424 57,224 11.14 5,137 1973 206,409.95 169,893 177,812 49,239 11.58 4,252 1974 199,306.77 161,902 169,448 49,789 12.03 4,139 1975 747,909.78 599,321 627,256 195,445 12.49 15,648 1976 887,070.27 700,862 733,530 242,247 12.96 18,692 1977 839,011.95 653,063 683,503 239,410 13.45 17,800 1978 2,833,094.25 2,171,323 2,272,530 843,874 13.95 60,493 1979 1,252,420.29 944,291 988,305 389,357 14.47 26,908 1980 1,783,566.94 1,322,160 1,383,787 578,137 15.00 38,542 1981 2,512,829.84 1,830,313 1,915,625 848,488 15.54 54,600 1982 1,473,629.80 1,054,002 1,103,130 517,863 16.09 32,185 1983 4,268,195.20 2,994,621 3,134,202 1,560,813 16.66 93,686 1984 10,513,029.39 7,232,680 7,569,799 3,994,533 17.23 231,836 1985 7,202,298.43 4,853,420 5,079,641 2,842,887 17.82 159,534 1986 3,989,858.17 2,630,454 2,753,061 1,635,783 18.43 88,757 1987 2,856,654.07 1,841,682 1,927,524 1,214,795 19.04 63,802 1988 1,112,717.31 700,599 733,254 490,735 19.67 24,948 1989 503,195.96 309,249 323,663 229,853 20.30 11,323 1990 430,303.71 257,764 269,779 203,555 20.95 9,716 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-135 Attachment C J. Spanos, Avista Page 615 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 353.00 STATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 46-R2 NET SALVAGE PERCENT.. -10 1991 822,299.08 479,599 501,953 402,576 21.61 18,629 1992 904,001.81 512,763 536,663 457,739 22.28 20,545 1993 3,694,927.66 2,035,746 2,130,633 1,933,787 22.96 84,224 1994 3,824,114.81 2,043,825 2,139,089 2,067,437 23.65 87,418 1995 1,964,090.39 1,016,364 1,063,737 1,096,762 24.36 45,023 1996 1,320,764.34 661,043 691,855 760,986 25.07 30,354 1997 2,705,729.81 1,307,639 1,368,589 1,607,714 25.79 62,339 1998 1,833,330.45 854,017 893,823 1,122,840 26.52 42,339 1999 4,624,107.97 2,072,197 2,168,783 2,917,736 27.26 107,034 2000 3,766,446.39 1,620,321 1,695,845 2,447,246 28.01 87,370 2001 6,329,930.83 2,608,102 2,729,667 4,233,257 28.77 147,141 2002 3,523,267.29 1,387,618 1,452,296 2,423,298 29.53 82,062 2003 8,052,888.98 3,021,436 3,162,267 5,695,911 30.31 187,922 2004 14,370,568.26 5,123,726 5,362,546 10,445,079 31.09 335,963 2005 12,494,622.74 4,215,861 4,412,365 9,331,720 31.89 292,622 2006 8,839,662.61 2,813,532 2,944,672 6,778,957 32.69 207,371 2007 8,718,258.83 2,608,119 2,729,685 6,860,400 33.49 204,849 2008 6,140,773.95 1,716,610 1,796,622 4,958,229 34.31 144,513 2009 6,356,152.15 1,652,155 1,729,163 5,262,604 35.13 149,804 2010 18,353,654.15 4,402,014 4,607,194 15,581,826 35.97 433,189 2011 11,268,587.31 2,479,089 2,594,641 9,800,805 36.80 266,326 2012 11,163,001.38 2,228,939 2,332,831 9,946,471 37.65 264,182 2013 6,037,178.33 1,082,732 1,133,199 5,507,697 38.50 143,057 2014 19,817,583.09 3,146,735 3,293,406 18,505,935 39.36 470,171 2015 9,476,678.28 1,307,526 1,368,470 9,055,876 40.23 225,103 2016 15,386,763.49 1,802,898 1,886,932 15,038,508 41.10 365,900 2017 4,113,070.58 395,385 413,814 4,110,564 41.98 97,917 2018 13,174,594.32 989,228 1,035,336 13,456,718 42.86 313,969 2019 23,797,482.91 1,280,328 1,340,005 24,837,226 43.75 567,708 2020 31,788,434.39 1,026,290 1,074,126 33,893,152 44.65 759,085 2021 44,218,428.22 475,702 497,875 48,142,396 45.55 1,056,913 354,761,236.38 90,866,559 95,101,385 295,135,975 8,298,195 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 35.6 2.34 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-136 Attachment C J. Spanos, Avista Page 616 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 354.00 TOWERS AND FIXTURES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 80-R4 NET SALVAGE PERCENT.. -10 1910 108,255.77 115,807 119,081 1929 2,885.08 2,891 3,174 1941 179.00 169 197 1954 15,258.68 12,796 15,566 1,219 19.01 64 1955 34,627.43 28,720 34,938 3,152 19.68 160 1956 178.00 146 178 18 20.37 1 1957 87,958.05 71,271 86,701 10,053 21.07 477 1959 93,197.08 73,697 89,653 12,864 22.49 572 1960 24,565.49 19,182 23,335 3,687 23.21 159 1962 25,877.85 19,681 23,942 4,524 24.69 183 1963 12,415.50 9,314 11,331 2,326 25.44 91 1964 3.46 3 4 1969 3,397.26 2,329 2,833 904 30.15 30 1970 396.33 267 325 111 30.97 4 1971 105,739.00 70,092 85,267 31,046 31.79 977 1972 716.34 467 568 220 32.63 7 1973 84,598.66 54,125 65,843 27,216 33.47 813 1975 305,906.03 188,522 229,338 107,159 35.18 3,046 1976 1,665,076.07 1,006,235 1,224,089 607,495 36.05 16,851 1977 24,415.81 14,459 17,589 9,268 36.93 251 1978 6,424.75 3,727 4,534 2,533 37.81 67 1979 11,825.78 6,716 8,170 4,838 38.70 125 1980 5,043.93 2,802 3,409 2,139 39.60 54 1982 604,025.36 320,420 389,792 274,636 41.42 6,631 1983 21,228.33 10,993 13,373 9,978 42.34 236 1984 12,845,360.08 6,489,155 7,894,083 6,235,813 43.26 144,147 1985 278,328.19 137,044 166,715 139,446 44.19 3,156 1986 301,697.13 144,694 176,021 155,846 45.12 3,454 1987 78,774.61 36,762 44,721 41,931 46.06 910 1988 81,315.05 36,886 44,872 44,575 47.01 948 1989 818.56 361 439 461 47.96 10 1990 294.58 126 153 171 48.91 3 1991 3,025.78 1,254 1,525 1,803 49.87 36 1992 47.07 19 23 29 50.83 1 1993 106,690.45 41,383 50,343 67,016 51.79 1,294 1994 52,303.55 19,590 23,831 33,703 52.76 639 1995 5,433.78 1,963 2,388 3,589 53.73 67 1996 6,811.43 2,370 2,883 4,610 54.70 84 1997 9,839.83 3,290 4,002 6,822 55.68 123 1998 3,724.72 1,195 1,454 2,643 56.66 47 1999 8,553.31 2,630 3,199 6,210 57.64 108 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-137 Attachment C J. Spanos, Avista Page 617 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 354.00 TOWERS AND FIXTURES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 80-R4 NET SALVAGE PERCENT.. -10 2000 8,230.73 2,420 2,944 6,110 58.62 104 2001 9,933.44 2,785 3,388 7,539 59.61 126 2002 10,577.19 2,823 3,434 8,201 60.59 135 2003 4,308.78 1,091 1,327 3,413 61.58 55 2004 1,675.99 402 489 1,355 62.57 22 2007 10,714.39 2,130 2,591 9,195 65.54 140 2008 18,359.93 3,398 4,134 16,062 66.54 241 2009 14,714.72 2,523 3,069 13,117 67.53 194 2010 7,791.94 1,229 1,495 7,076 68.53 103 2012 1,533.08 200 243 1,443 70.52 20 2013 10,227.70 1,194 1,453 9,797 71.51 137 2014 35,285.79 3,634 4,421 34,393 72.51 474 2020 92,968.59 1,917 2,333 99,932 78.50 1,273 2021 24,848.36 171 208 27,125 79.50 341 17,278,383.79 8,979,470 10,901,411 8,104,811 189,191 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 42.8 1.09 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-138 Attachment C J. Spanos, Avista Page 618 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 355.00 POLES AND FIXTURES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 60-R2.5 NET SALVAGE PERCENT.. -40 1946 4,632.07 5,531 5,008 1,477 8.83 167 1947 15,360.30 18,239 16,514 4,990 9.11 548 1950 8,721.88 10,180 9,217 2,994 9.98 300 1952 110,695.64 127,544 115,484 39,490 10.62 3,718 1953 19,832.39 22,698 20,552 7,213 10.95 659 1954 117,388.40 133,393 120,780 43,564 11.30 3,855 1955 32,103.47 36,211 32,787 12,158 11.66 1,043 1956 19,389.52 21,703 19,651 7,494 12.03 623 1957 293,436.37 325,773 294,969 115,842 12.42 9,327 1958 16,062.60 17,683 16,011 6,477 12.82 505 1959 364,898.15 398,213 360,559 150,298 13.23 11,360 1960 351,431.09 379,989 344,058 147,946 13.66 10,831 1961 38,736.63 41,478 37,556 16,675 14.11 1,182 1962 364,566.73 386,455 349,913 160,480 14.57 11,014 1963 563,053.81 590,678 534,825 253,450 15.04 16,852 1964 48,136.11 49,948 45,225 22,166 15.53 1,427 1965 893,709.99 916,912 830,211 420,983 16.03 26,262 1966 382,412.92 387,705 351,045 184,333 16.55 11,138 1967 108,947.09 109,106 98,789 53,737 17.08 3,146 1968 250,562.60 247,772 224,343 126,445 17.62 7,176 1969 178,097.96 173,788 157,355 91,982 18.18 5,060 1970 87,091.98 83,826 75,900 46,029 18.75 2,455 1971 236,614.06 224,485 203,258 128,002 19.34 6,619 1972 276,149.65 258,189 233,775 152,835 19.93 7,669 1973 987,426.32 909,161 823,193 559,204 20.54 27,225 1974 651,121.95 590,087 534,290 377,281 21.16 17,830 1975 670,586.00 597,869 541,336 397,484 21.79 18,242 1976 712,249.05 624,215 565,191 431,958 22.44 19,249 1977 355,940.02 306,549 277,563 220,753 23.09 9,561 1978 383,529.98 324,313 293,647 243,295 23.76 10,240 1979 263,673.13 218,839 198,146 170,996 24.43 6,999 1980 701,444.57 571,046 517,049 464,973 25.11 18,517 1981 722,821.48 576,640 522,115 489,835 25.81 18,978 1982 1,473,813.56 1,151,694 1,042,793 1,020,546 26.51 38,497 1983 1,639,670.62 1,253,754 1,135,202 1,160,337 27.23 42,612 1984 1,397,733.74 1,045,278 946,439 1,010,388 27.95 36,150 1985 10,033,274.14 7,332,317 6,638,993 7,407,591 28.68 258,284 1986 9,537,198.47 6,805,154 6,161,677 7,190,401 29.42 244,405 1987 2,123,381.67 1,477,954 1,338,203 1,634,531 30.17 54,177 1988 1,062,768.37 721,129 652,941 834,935 30.92 27,003 1989 824,945.18 544,927 493,400 661,523 31.69 20,875 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-139 Attachment C J. Spanos, Avista Page 619 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 355.00 POLES AND FIXTURES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 60-R2.5 NET SALVAGE PERCENT.. -40 1990 1,161,946.56 746,667 676,064 950,661 32.46 29,287 1991 1,064,404.20 664,614 601,770 888,396 33.24 26,727 1992 724,937.52 439,285 397,747 617,166 34.03 18,136 1993 2,556,964.58 1,502,314 1,360,259 2,219,491 34.82 63,742 1994 3,948,304.85 2,245,156 2,032,860 3,494,767 35.63 98,085 1995 4,268,401.80 2,346,503 2,124,624 3,851,139 36.44 105,684 1996 578,772.12 307,234 278,183 532,098 37.25 14,285 1997 4,165,827.27 2,130,662 1,929,193 3,902,965 38.08 102,494 1998 1,322,824.19 650,962 589,409 1,262,545 38.91 32,448 1999 1,229,949.63 581,444 526,464 1,195,465 39.74 30,082 2000 3,144,340.92 1,424,072 1,289,416 3,112,661 40.59 76,685 2001 940,594.37 407,336 368,819 948,013 41.44 22,877 2002 1,955,054.99 807,438 731,089 2,005,988 42.30 47,423 2003 698,120.45 274,318 248,379 728,990 43.16 16,890 2004 13,926,309.91 5,189,472 4,698,770 14,798,064 44.03 336,090 2005 7,106,743.83 2,503,976 2,267,207 7,682,234 44.90 171,097 2006 5,461,511.77 1,812,130 1,640,780 6,005,336 45.78 131,178 2007 24,957,056.58 7,762,593 7,028,584 27,911,295 46.67 598,056 2008 2,317,006.96 672,539 608,946 2,634,864 47.56 55,401 2009 3,311,444.54 892,434 808,048 3,827,974 48.45 79,009 2010 3,535,430.41 878,554 795,480 4,154,123 49.35 84,177 2011 9,502,090.49 2,159,464 1,955,271 11,347,656 50.26 225,779 2012 11,880,324.92 2,447,798 2,216,341 14,416,114 51.17 281,730 2013 9,075,725.35 1,677,194 1,518,603 11,187,412 52.08 214,812 2014 17,572,497.30 2,870,257 2,598,853 22,002,643 53.00 415,144 2015 22,636,386.50 3,211,243 2,907,597 28,783,344 53.92 533,816 2016 14,011,581.99 1,683,660 1,524,458 18,091,757 54.85 329,841 2017 35,588,190.14 3,512,554 3,180,417 46,643,049 55.77 836,347 2018 17,295,108.12 1,327,607 1,202,072 23,011,079 56.71 405,768 2019 20,616,891.92 1,135,207 1,027,865 27,835,784 57.64 482,925 2020 15,339,060.18 508,306 460,242 21,014,442 58.58 358,731 2021 33,450,940.15 366,689 332,016 46,499,301 59.53 781,107 333,668,354.17 85,158,107 77,105,789 390,029,907 8,017,633 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 48.6 2.40 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-140 Attachment C J. Spanos, Avista Page 620 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 356.00 OVERHEAD CONDUCTORS AND DEVICES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 60-R3 NET SALVAGE PERCENT.. -30 1919 238,429.97 309,959 309,959 1920 70,971.77 92,263 92,263 1922 9,792.31 12,624 10,120 2,610 0.50 2,610 1924 117,936.30 150,941 120,996 32,321 0.93 32,321 1926 258,878.59 328,691 263,483 73,059 1.40 52,185 1927 10,916.84 13,804 11,065 3,127 1.64 1,907 1928 106,180.25 133,710 107,184 30,850 1.88 16,410 1929 157,306.80 197,239 158,110 46,389 2.13 21,779 1930 140,466.27 175,393 140,598 42,008 2.37 17,725 1931 18,267.42 22,707 18,202 5,546 2.63 2,109 1935 12,046.11 14,707 11,789 3,871 3.65 1,061 1936 74,052.62 90,011 72,154 24,114 3.90 6,183 1937 82,226.75 99,484 79,748 27,147 4.16 6,526 1940 28,692.01 34,235 27,443 9,857 4.93 1,999 1941 25.46 30 24 9 5.19 2 1942 110,401.09 130,485 104,599 38,922 5.45 7,142 1946 47,286.54 54,792 43,922 17,551 6.52 2,692 1947 169,259.33 195,100 156,395 63,642 6.80 9,359 1948 2,600.78 2,981 2,390 991 7.09 140 1949 10,418.54 11,878 9,522 4,022 7.38 545 1950 129,958.92 147,293 118,072 50,875 7.69 6,616 1952 565,831.71 633,460 507,791 227,790 8.33 27,346 1953 104,050.09 115,719 92,762 42,503 8.67 4,902 1954 132,766.02 146,649 117,556 55,040 9.02 6,102 1955 53,248.77 58,402 46,816 22,407 9.38 2,389 1956 5,854.66 6,373 5,109 2,502 9.76 256 1957 1,202,880.44 1,299,206 1,041,462 522,283 10.15 51,456 1958 89,814.57 96,209 77,123 39,636 10.56 3,753 1959 1,648,725.85 1,751,112 1,403,716 739,628 10.98 67,361 1960 998,275.79 1,050,756 842,301 455,458 11.42 39,882 1961 6,011.85 6,269 5,025 2,790 11.87 235 1962 587,837.63 607,018 486,594 277,595 12.34 22,496 1963 777,059.36 794,171 636,619 373,558 12.83 29,116 1964 114,739.53 116,022 93,005 56,156 13.33 4,213 1965 1,423,040.82 1,422,928 1,140,639 709,314 13.85 51,214 1966 233,488.89 230,787 185,002 118,534 14.38 8,243 1967 42,361.47 41,367 33,160 21,910 14.93 1,468 1968 287,864.53 277,611 222,537 151,687 15.49 9,793 1969 79,474.87 75,646 60,639 42,678 16.07 2,656 1970 95,430.98 89,612 71,834 52,226 16.66 3,135 1971 239,625.98 221,851 177,839 133,675 17.27 7,740 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-141 Attachment C J. Spanos, Avista Page 621 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 356.00 OVERHEAD CONDUCTORS AND DEVICES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 60-R3 NET SALVAGE PERCENT.. -30 1972 200,959.76 183,351 146,977 114,271 17.89 6,387 1973 411,619.48 369,849 296,476 238,629 18.53 12,878 1974 424,919.27 375,811 301,255 251,140 19.18 13,094 1975 1,127,976.02 981,485 786,772 679,597 19.84 34,254 1976 638,798.51 546,569 438,138 392,300 20.51 19,127 1977 313,392.39 263,525 211,245 196,165 21.19 9,257 1978 553,277.60 456,853 366,220 353,041 21.89 16,128 1979 297,735.32 241,264 193,401 193,655 22.60 8,569 1980 928,111.91 737,597 591,268 615,277 23.32 26,384 1981 559,896.02 436,115 349,596 378,269 24.05 15,728 1982 1,356,872.20 1,035,129 829,774 934,160 24.79 37,683 1983 1,797,127.09 1,342,184 1,075,914 1,260,351 25.53 49,367 1984 12,628,564.69 9,223,638 7,393,800 9,023,334 26.29 343,223 1985 4,447,795.68 3,174,392 2,544,638 3,237,496 27.06 119,641 1986 5,526,724.60 3,851,022 3,087,034 4,097,708 27.84 147,188 1987 1,419,414.93 964,747 773,355 1,071,884 28.63 37,439 1988 536,614.13 355,545 285,010 412,588 29.42 14,024 1989 462,413.21 298,266 239,094 362,043 30.23 11,976 1990 664,122.21 416,717 334,046 529,313 31.04 17,053 1991 742,194.92 452,516 362,743 602,110 31.86 18,899 1992 351,394.17 207,927 166,677 290,135 32.69 8,875 1993 2,402,890.16 1,378,108 1,104,711 2,019,046 33.53 60,216 1994 1,658,396.10 920,576 737,947 1,417,968 34.38 41,244 1995 1,828,366.90 981,246 786,581 1,590,296 35.23 45,140 1996 152,900.93 79,210 63,496 135,275 36.09 3,748 1997 2,884,322.80 1,439,854 1,154,208 2,595,412 36.96 70,222 1998 463,728.95 222,650 178,479 424,369 37.84 11,215 1999 505,037.24 232,858 186,662 469,886 38.72 12,135 2000 1,359,558.18 600,624 481,469 1,285,957 39.61 32,465 2001 681,040.62 287,589 230,535 654,818 40.51 16,164 2002 1,288,408.49 518,944 415,993 1,258,938 41.41 30,402 2003 630,238.33 241,426 193,531 625,779 42.32 14,787 2004 3,620,807.10 1,314,820 1,053,979 3,653,070 43.24 84,484 2005 3,783,766.50 1,298,589 1,040,967 3,877,929 44.16 87,815 2006 2,902,653.03 938,344 752,190 3,021,259 45.08 67,020 2007 26,300,235.42 7,966,341 6,385,933 27,804,373 46.02 604,180 2008 3,827,195.42 1,081,294 866,781 4,108,573 46.96 87,491 2009 2,403,488.39 630,125 505,117 2,619,418 47.90 54,685 2010 1,981,291.89 478,639 383,684 2,191,995 48.85 44,872 2011 4,178,221.76 923,387 740,200 4,691,488 49.80 94,207 2012 4,018,684.63 805,429 645,643 4,578,647 50.75 90,220 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-142 Attachment C J. Spanos, Avista Page 622 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 356.00 OVERHEAD CONDUCTORS AND DEVICES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 60-R3 NET SALVAGE PERCENT.. -30 2013 3,952,491.26 709,950 569,106 4,569,133 51.71 88,361 2014 5,026,795.11 797,250 639,087 5,895,747 52.68 111,916 2015 3,902,763.68 537,801 431,109 4,642,484 53.64 86,549 2016 3,714,442.86 432,996 347,096 4,481,680 54.62 82,052 2017 12,817,152.51 1,224,679 981,720 15,680,578 55.59 282,076 2018 8,697,878.83 648,244 519,642 10,787,600 56.56 190,728 2019 9,188,732.06 489,759 392,598 11,552,754 57.54 200,778 2020 4,858,078.62 155,803 124,894 6,190,608 58.52 105,786 2021 10,358,346.63 110,016 88,190 13,377,660 59.51 224,797 175,262,336.99 64,620,548 51,880,548 175,960,490 4,425,996 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 39.8 2.53 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-143 Attachment C J. Spanos, Avista Page 623 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 357.00 UNDERGROUND CONDUIT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 60-R4 NET SALVAGE PERCENT.. 0 1974 96,420.97 70,033 73,175 23,246 16.42 1,416 1976 276,899.41 194,430 203,153 73,746 17.87 4,127 1978 42.02 28 29 13 19.37 1 1985 149,012.69 86,924 90,824 58,189 25.00 2,328 1986 33,487.58 19,060 19,915 13,573 25.85 525 1994 191.00 86 90 101 33.03 3 1999 159.35 59 62 97 37.76 3 2000 3,229.97 1,146 1,197 2,033 38.72 53 2001 1,704.88 577 603 1,102 39.69 28 2008 2,044,339.71 457,932 478,476 1,565,864 46.56 33,631 2014 381,602.20 47,635 49,772 331,830 52.51 6,319 2017 12,664.45 948 991 11,673 55.51 210 2020 107,173.95 2,679 2,799 104,375 58.50 1,784 2021 417,756.79 3,480 3,636 414,121 59.50 6,960 3,524,684.97 885,017 924,722 2,599,963 57,388 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 45.3 1.63 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-144 Attachment C J. Spanos, Avista Page 624 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 358.00 UNDERGROUND CONDUCTORS AND DEVICES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 50-S3 NET SALVAGE PERCENT.. 0 1974 142,464.86 111,465 97,945 44,520 10.88 4,092 1976 77,029.32 58,912 51,767 25,262 11.76 2,148 1983 4,092.98 2,831 2,488 1,605 15.42 104 1984 27,484.51 18,673 16,408 11,077 16.03 691 1985 588,766.12 392,589 344,972 243,794 16.66 14,633 1995 1,024.64 529 465 560 24.21 23 1998 1,711.88 792 696 1,016 26.87 38 1999 229.44 102 90 139 27.79 5 2000 324.61 138 121 204 28.72 7 2004 376.94 131 115 262 32.56 8 2008 1,120,161.38 302,220 265,563 854,598 36.51 23,407 2013 3,778.04 642 564 3,214 41.50 77 2014 1,901.52 285 250 1,652 42.50 39 2017 736,357.89 66,272 58,234 678,124 45.50 14,904 2020 107,173.95 3,215 2,825 104,349 48.50 2,152 2021 4,482,508.88 44,825 39,389 4,443,120 49.50 89,760 7,295,386.96 1,003,621 881,892 6,413,495 152,088 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 42.2 2.08 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-145 Attachment C J. Spanos, Avista Page 625 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 359.00 ROADS AND TRAILS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 75-R4 NET SALVAGE PERCENT.. 0 1926 14,129.99 13,324 14,130 1930 11,923.00 11,074 11,923 1952 95.21 78 86 9 13.86 1 1953 97.00 78 86 11 14.46 1 1960 114.00 85 94 20 19.03 1 1972 5,902.51 3,696 4,084 1,819 28.04 65 1984 94,111.68 45,926 50,752 43,360 38.40 1,129 1985 788,011.99 374,881 414,277 373,735 39.32 9,505 1986 848,667.02 393,332 434,666 414,001 40.24 10,288 1988 33,911.38 14,876 16,439 17,472 42.10 415 1990 5,257.70 2,175 2,404 2,854 43.98 65 1992 251.05 97 107 144 45.88 3 1993 495.95 186 206 290 46.84 6 1995 5,464.55 1,911 2,112 3,353 48.77 69 1996 4,170.97 1,405 1,553 2,618 49.73 53 1998 1,797.17 559 618 1,179 51.68 23 2001 7,567.17 2,056 2,272 5,295 54.62 97 2002 3,941.06 1,019 1,126 2,815 55.60 51 2003 934.96 230 254 681 56.59 12 2008 45,401.63 8,148 9,004 36,398 61.54 591 2012 45,252.45 5,720 6,321 38,931 65.52 594 2013 77,612.62 8,776 9,698 67,915 66.52 1,021 2014 2,016.43 201 222 1,794 67.51 27 2015 20,246.20 1,752 1,936 18,310 68.51 267 2016 34,491.78 2,525 2,790 31,702 69.51 456 2018 2,078.20 97 107 1,971 71.50 28 2019 59,258.85 1,975 2,183 57,076 72.50 787 2020 47,908.30 958 1,059 46,849 73.50 637 2021 415,090.47 2,769 3,060 412,030 74.50 5,531 2,576,201.29 899,909 993,569 1,582,632 31,723 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 49.9 1.23 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-146 Attachment C J. Spanos, Avista Page 626 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 360.40 LAND - EASEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 75-R4 NET SALVAGE PERCENT.. 0 2009 58,251.77 9,686 9,353 48,899 62.53 782 2010 1,728,577.28 264,351 255,274 1,473,303 63.53 23,191 2011 146,825.34 20,516 19,811 127,014 64.52 1,969 2012 1,749.16 221 213 1,536 65.52 23 2013 268,792.89 30,392 29,349 239,444 66.52 3,600 2014 112,219.88 11,207 10,822 101,398 67.51 1,502 2015 219,222.82 18,969 18,318 200,905 68.51 2,932 2016 7,879.94 577 557 7,323 69.51 105 2017 81,166.53 4,859 4,692 76,475 70.51 1,085 2018 103,807.69 4,845 4,679 99,129 71.50 1,386 2019 1,032,263.88 34,405 33,223 999,041 72.50 13,780 2020 931.50 19 18 914 73.50 12 2021 157,550.64 1,051 1,016 156,535 74.50 2,101 3,919,239.32 401,098 387,325 3,531,915 52,468 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 67.3 1.34 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-147 Attachment C J. Spanos, Avista Page 627 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 361.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 63-S1 NET SALVAGE PERCENT.. -15 1910 241.39 260 278 1912 198,919.47 212,454 228,757 1915 2,428.35 2,555 2,793 1916 1,094.00 1,145 1,258 1917 7,605.83 7,923 8,747 1919 435.00 448 500 1920 82.86 85 95 1925 9,102.51 9,084 10,328 140 8.33 17 1926 13,523.33 13,419 15,257 295 8.64 34 1927 11,352.99 11,201 12,735 321 8.95 36 1929 15,158.53 14,782 16,806 626 9.58 65 1930 3,506.01 3,398 3,863 169 9.90 17 1931 6,874.64 6,623 7,530 376 10.22 37 1933 2,104.45 2,003 2,277 143 10.86 13 1934 2,578.87 2,439 2,773 193 11.19 17 1935 142.88 134 152 12 11.52 1 1936 5,794.72 5,409 6,150 514 11.86 43 1937 8,299.87 7,698 8,752 793 12.19 65 1939 41.00 38 43 4 12.87 1940 1,364.75 1,240 1,410 159 13.22 12 1941 303.88 274 312 37 13.57 3 1942 190.86 171 194 25 13.92 2 1943 2,166.01 1,927 2,191 300 14.27 21 1944 701.32 619 704 103 14.63 7 1945 2,256.84 1,978 2,249 346 14.99 23 1946 358.04 311 354 58 15.35 4 1947 101.38 87 99 18 15.72 1 1948 2,456.41 2,103 2,391 434 16.09 27 1949 9,213.09 7,827 8,899 1,696 16.46 103 1950 5,262.74 4,434 5,041 1,011 16.84 60 1951 6,845.87 5,720 6,503 1,370 17.23 80 1952 2,250.37 1,865 2,120 468 17.61 27 1954 2,128.87 1,733 1,970 478 18.40 26 1955 14,130.79 11,401 12,962 3,288 18.80 175 1956 24,291.57 19,422 22,082 5,853 19.20 305 1957 9,961.67 7,890 8,971 2,485 19.61 127 1958 22,207.64 17,423 19,809 5,730 20.02 286 1959 97.00 75 85 27 20.44 1 1960 9,667.71 7,437 8,456 2,662 20.86 128 1961 1,872.98 1,426 1,621 533 21.28 25 1962 936.52 706 803 274 21.72 13 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-148 Attachment C J. Spanos, Avista Page 628 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 361.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 63-S1 NET SALVAGE PERCENT.. -15 1963 6,595.47 4,918 5,592 1,993 22.15 90 1965 8,936.62 6,519 7,412 2,865 23.04 124 1966 23,769.73 17,139 19,486 7,849 23.50 334 1967 9,905.50 7,059 8,026 3,365 23.96 140 1968 30,878.46 21,746 24,724 10,786 24.42 442 1969 15,033.07 10,458 11,890 5,398 24.89 217 1970 19,866.23 13,646 15,515 7,331 25.37 289 1971 20,291.08 13,756 15,640 7,695 25.86 298 1972 47,044.81 31,474 35,784 18,318 26.35 695 1973 49,819.98 32,875 37,377 19,916 26.85 742 1974 62,477.33 40,657 46,225 25,624 27.35 937 1975 329,915.28 211,623 240,606 138,797 27.86 4,982 1976 327,240.16 206,799 235,121 141,205 28.38 4,976 1977 52,431.48 32,627 37,095 23,201 28.91 803 1978 147,081.81 90,103 102,443 66,701 29.44 2,266 1979 134,269.74 80,906 91,986 62,424 29.99 2,081 1980 833,099.30 493,633 561,238 396,826 30.54 12,994 1981 102,525.54 59,701 67,877 50,027 31.10 1,609 1982 591,106.64 338,160 384,472 295,301 31.66 9,327 1983 262,720.52 147,514 167,717 134,412 32.24 4,169 1984 5,475.38 3,015 3,428 2,869 32.83 87 1985 287,009.55 154,970 176,194 153,867 33.42 4,604 1986 78,566.11 41,561 47,253 43,098 34.02 1,267 1987 673,046.36 348,425 396,143 377,860 34.64 10,908 1988 152,970.90 77,460 88,068 87,849 35.26 2,491 1989 161,125.05 79,706 90,622 94,672 35.90 2,637 1990 2,372.40 1,146 1,303 1,425 36.54 39 1991 318,592.69 150,041 170,590 195,792 37.20 5,263 1992 237,230.89 108,867 123,777 149,039 37.86 3,937 1993 32,341.13 14,440 16,418 20,774 38.54 539 1994 85,660.45 37,168 42,258 56,252 39.23 1,434 1995 318,718.59 134,218 152,600 213,926 39.93 5,358 1996 146,507.43 59,798 67,988 100,496 40.64 2,473 1997 202,628.14 80,004 90,961 142,061 41.37 3,434 1998 124,341.49 47,438 53,935 89,058 42.10 2,115 1999 1,397,781.22 514,126 584,537 1,022,911 42.85 23,872 2000 238,679.24 84,480 96,050 178,431 43.61 4,092 2001 345,646.96 117,420 133,501 263,993 44.39 5,947 2002 516,615.67 168,144 191,172 402,936 45.17 8,920 2003 124,467.07 38,670 43,966 99,171 45.98 2,157 2004 103,046.28 30,491 34,667 83,836 46.79 1,792 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-149 Attachment C J. Spanos, Avista Page 629 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 361.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 63-S1 NET SALVAGE PERCENT.. -15 2005 83,137.29 23,341 26,538 69,070 47.62 1,450 2006 144,267.14 38,290 43,534 122,373 48.46 2,525 2007 634,390.73 158,531 180,242 549,307 49.31 11,140 2008 1,427,290.99 334,005 379,748 1,261,637 50.18 25,142 2009 1,808,377.10 394,132 448,110 1,631,524 51.06 31,953 2010 467,157.09 94,230 107,135 430,096 51.95 8,279 2011 3,127,736.50 578,921 658,207 2,938,690 52.86 55,594 2012 1,463,954.34 246,657 280,438 1,403,109 53.77 26,095 2013 547,493.58 82,851 94,198 535,420 54.71 9,787 2014 954,935.38 128,124 145,671 952,505 55.65 17,116 2015 163,516.49 19,103 21,719 166,325 56.60 2,939 2016 1,062,198.76 105,479 119,925 1,101,604 57.56 19,138 2017 3,112,357.30 253,372 288,072 3,291,139 58.54 56,220 2018 1,757,775.46 111,664 126,957 1,894,485 59.52 31,829 2019 1,229,909.39 55,897 63,552 1,350,844 60.51 22,324 2020 1,202,801.34 32,935 37,445 1,345,777 61.50 21,883 2021 610,626.65 5,576 6,340 695,881 62.50 11,134 28,833,810.29 7,213,176 8,187,808 24,971,074 497,230 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 50.2 1.72 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-150 Attachment C J. Spanos, Avista Page 630 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 362.00 STATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 43-R1.5 NET SALVAGE PERCENT.. -10 1923 788.30 867 867 1926 10,228.41 11,251 11,251 1937 8,410.83 9,114 8,972 280 0.64 280 1939 124.66 133 131 6 1.30 5 1940 183.87 195 192 10 1.64 6 1941 4,590.34 4,817 4,742 307 1.98 155 1942 2,460.29 2,561 2,521 185 2.31 80 1943 1,893.57 1,956 1,925 158 2.61 61 1944 25,260.06 25,919 25,514 2,272 2.89 786 1945 60,591.97 61,784 60,820 5,831 3.14 1,857 1946 1,797.02 1,822 1,794 183 3.37 54 1947 1,490.52 1,503 1,480 160 3.59 45 1948 1,743.30 1,747 1,720 198 3.82 52 1949 46,233.60 46,079 45,360 5,497 4.04 1,361 1950 2,340.82 2,319 2,283 292 4.28 68 1951 183,383.64 180,517 177,699 24,023 4.52 5,315 1952 14,120.36 13,813 13,597 1,935 4.76 407 1953 34,305.29 33,331 32,811 4,925 5.02 981 1954 3,743.13 3,612 3,556 561 5.28 106 1955 22,540.86 21,595 21,258 3,537 5.55 637 1956 80,070.53 76,156 74,967 13,111 5.82 2,253 1957 215,438.48 203,364 200,190 36,792 6.10 6,031 1958 54,538.74 51,078 50,281 9,712 6.39 1,520 1959 11,561.27 10,742 10,574 2,143 6.68 321 1960 107,969.93 99,516 97,963 20,804 6.97 2,985 1961 12,034.57 11,000 10,828 2,410 7.27 331 1962 13,397.96 12,143 11,953 2,785 7.57 368 1963 97,325.56 87,439 86,074 20,984 7.88 2,663 1964 20,642.11 18,376 18,089 4,617 8.20 563 1965 27,570.84 24,319 23,939 6,389 8.52 750 1966 43,585.38 38,077 37,483 10,461 8.85 1,182 1967 79,821.41 69,038 67,960 19,844 9.19 2,159 1968 305,709.63 261,673 257,588 78,693 9.54 8,249 1969 142,125.79 120,381 118,502 37,836 9.89 3,826 1970 180,589.71 151,251 148,890 49,759 10.26 4,850 1971 191,485.27 158,515 156,041 54,593 10.64 5,131 1972 373,624.27 305,659 300,888 110,099 11.02 9,991 1973 138,777.64 112,113 110,363 42,292 11.42 3,703 1974 436,028.09 347,675 342,248 137,383 11.83 11,613 1975 1,266,298.52 996,111 980,562 412,366 12.25 33,663 1976 1,397,979.37 1,083,948 1,067,028 470,749 12.69 37,096 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-151 Attachment C J. Spanos, Avista Page 631 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 362.00 STATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 43-R1.5 NET SALVAGE PERCENT.. -10 1977 674,331.23 515,267 507,224 234,540 13.13 17,863 1978 1,086,719.67 817,588 804,826 390,566 13.59 28,739 1979 2,112,591.37 1,563,998 1,539,585 784,266 14.06 55,780 1980 3,457,275.80 2,517,056 2,477,766 1,325,237 14.54 91,144 1981 1,037,569.79 742,125 730,541 410,786 15.04 27,313 1982 2,953,075.33 2,074,417 2,042,037 1,206,346 15.54 77,628 1983 1,719,796.63 1,185,217 1,166,717 725,059 16.06 45,147 1984 161,449.18 109,077 107,374 70,220 16.59 4,233 1985 1,224,293.68 810,229 797,582 549,141 17.13 32,057 1986 1,422,061.61 920,728 906,356 657,912 17.69 37,191 1987 2,043,022.42 1,293,515 1,273,324 974,001 18.25 53,370 1988 672,684.55 415,920 409,428 330,525 18.83 17,553 1989 675,061.41 407,202 400,846 341,722 19.42 17,596 1990 826,680.45 486,183 478,594 430,754 20.01 21,527 1991 2,221,316.33 1,271,741 1,251,890 1,191,558 20.62 57,787 1992 1,158,031.28 644,624 634,562 639,272 21.24 30,098 1993 671,331.86 362,882 357,218 381,247 21.87 17,432 1994 1,140,468.20 597,789 588,458 666,057 22.51 29,589 1995 1,479,278.29 750,793 739,074 888,132 23.16 38,348 1996 1,073,818.07 526,874 518,650 662,550 23.82 27,815 1997 1,725,528.02 817,067 804,313 1,093,768 24.49 44,662 1998 3,137,701.75 1,431,153 1,408,814 2,042,658 25.17 81,154 1999 4,214,681.78 1,849,082 1,820,219 2,815,931 25.85 108,934 2000 2,771,471.20 1,166,981 1,148,765 1,899,853 26.54 71,585 2001 1,493,502.23 601,744 592,351 1,050,501 27.25 38,550 2002 1,369,185.05 527,136 518,908 987,196 27.95 35,320 2003 2,668,251.07 978,143 962,875 1,972,201 28.67 68,790 2004 3,577,555.82 1,245,565 1,226,123 2,709,188 29.39 92,181 2005 4,072,408.63 1,341,789 1,320,844 3,158,805 30.12 104,874 2006 3,777,782.61 1,173,240 1,154,926 3,000,635 30.86 97,234 2007 2,520,496.35 735,057 723,583 2,048,963 31.60 64,841 2008 5,211,309.64 1,419,754 1,397,593 4,334,848 32.35 133,998 2009 7,340,821.60 1,857,228 1,828,238 6,246,666 33.11 188,664 2010 4,886,109.80 1,141,214 1,123,400 4,251,321 33.87 125,519 2011 10,592,907.25 2,268,100 2,232,696 9,419,502 34.63 272,004 2012 4,685,925.52 911,010 896,790 4,257,728 35.40 120,275 2013 2,050,465.68 357,724 352,140 1,903,372 36.18 52,608 2014 10,508,475.82 1,623,738 1,598,393 9,960,930 36.96 269,506 2015 5,520,834.36 741,443 729,870 5,343,048 37.75 141,538 2016 5,046,287.46 575,741 566,754 4,984,162 38.54 129,324 2017 4,209,233.29 394,119 387,967 4,242,190 39.34 107,834 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-152 Attachment C J. Spanos, Avista Page 632 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 362.00 STATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 43-R1.5 NET SALVAGE PERCENT.. -10 2018 8,888,136.82 650,265 640,115 9,136,836 40.14 227,624 2019 14,317,882.49 750,787 739,067 15,010,604 40.95 366,559 2020 9,199,779.98 289,425 284,907 9,834,851 41.77 235,453 2021 5,315,079.73 55,718 54,849 5,791,739 42.59 135,988 162,535,477.01 47,579,957 46,837,456 131,951,569 4,194,733 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 31.5 2.58 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-153 Attachment C J. Spanos, Avista Page 633 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 364.00 POLES, TOWERS AND FIXTURES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 63-R3 NET SALVAGE PERCENT.. -60 1946 3,711.01 5,189 4,346 1,592 7.94 201 1947 24,496.26 34,062 28,529 10,665 8.25 1,293 1948 28,574.53 39,500 33,084 12,635 8.57 1,474 1949 69,047.82 94,869 79,459 31,018 8.90 3,485 1950 61,616.61 84,111 70,449 28,138 9.25 3,042 1951 87,249.30 118,327 99,107 40,492 9.60 4,218 1952 100,223.52 134,981 113,056 47,302 9.97 4,744 1953 125,138.51 167,327 140,148 60,074 10.35 5,804 1954 134,752.44 178,815 149,770 65,834 10.75 6,124 1955 173,052.12 227,836 190,828 86,055 11.16 7,711 1956 254,306.61 332,100 278,156 128,735 11.58 11,117 1957 230,609.58 298,579 250,080 118,895 12.02 9,891 1958 199,745.51 256,281 214,653 104,940 12.48 8,409 1959 223,875.32 284,569 238,346 119,855 12.95 9,255 1960 178,301.02 224,468 188,007 97,275 13.43 7,243 1961 423,405.77 527,658 441,950 235,499 13.93 16,906 1962 285,438.37 351,948 294,781 161,920 14.45 11,206 1963 295,467.67 360,338 301,808 170,940 14.98 11,411 1964 284,189.47 342,687 287,024 167,679 15.52 10,804 1965 444,500.99 529,674 443,638 267,564 16.08 16,640 1966 378,228.96 445,136 372,832 232,334 16.66 13,946 1967 503,755.36 585,444 490,349 315,660 17.24 18,310 1968 456,767.69 523,880 438,785 292,043 17.84 16,370 1969 663,075.80 750,050 628,218 432,703 18.46 23,440 1970 825,683.50 920,776 771,213 549,881 19.09 28,805 1971 1,135,607.30 1,247,951 1,045,244 771,728 19.73 39,114 1972 1,001,500.01 1,084,040 907,958 694,442 20.38 34,075 1973 1,730,653.25 1,843,824 1,544,329 1,224,716 21.05 58,181 1974 1,140,947.29 1,196,151 1,001,858 823,658 21.72 37,922 1975 1,935,218.33 1,994,947 1,670,905 1,425,444 22.41 63,607 1976 2,234,718.36 2,263,931 1,896,197 1,679,352 23.11 72,668 1977 2,574,511.82 2,561,742 2,145,634 1,973,585 23.82 82,854 1978 2,907,975.11 2,840,417 2,379,044 2,273,716 24.54 92,653 1979 3,953,781.78 3,788,609 3,173,219 3,152,832 25.27 124,766 1980 3,318,783.35 3,117,745 2,611,325 2,698,728 26.01 103,757 1981 4,003,379.39 3,684,646 3,086,143 3,319,264 26.76 124,038 1982 2,869,484.28 2,586,347 2,166,242 2,424,933 27.51 88,147 1983 3,246,423.99 2,862,619 2,397,639 2,796,639 28.28 98,891 1984 3,659,329.42 3,154,225 2,641,879 3,213,048 29.06 110,566 1985 4,597,862.66 3,872,136 3,243,179 4,113,401 29.84 137,849 1986 3,847,831.24 3,163,287 2,649,469 3,507,061 30.63 114,498 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-154 Attachment C J. Spanos, Avista Page 634 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 364.00 POLES, TOWERS AND FIXTURES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 63-R3 NET SALVAGE PERCENT.. -60 1987 2,880,192.97 2,308,532 1,933,553 2,674,756 31.44 85,075 1988 2,786,982.38 2,176,522 1,822,986 2,636,186 32.25 81,742 1989 2,520,855.16 1,916,818 1,605,466 2,427,902 33.06 73,439 1990 2,427,787.53 1,794,854 1,503,313 2,381,147 33.89 70,261 1991 3,031,272.13 2,177,132 1,823,497 3,026,538 34.72 87,170 1992 3,667,811.66 2,556,083 2,140,894 3,727,605 35.56 104,826 1993 3,995,472.63 2,698,127 2,259,866 4,132,890 36.41 113,510 1994 4,814,665.14 3,146,172 2,635,134 5,068,330 37.27 135,990 1995 11,169,196.88 7,054,643 5,908,746 11,961,969 38.13 313,715 1996 7,949,959.66 4,845,659 4,058,571 8,661,364 39.00 222,086 1997 7,047,432.31 4,138,027 3,465,881 7,810,011 39.88 195,838 1998 7,283,609.02 4,112,151 3,444,208 8,209,566 40.77 201,363 1999 7,160,101.51 3,880,546 3,250,223 8,205,939 41.66 196,974 2000 7,702,928.61 4,000,593 3,350,770 8,973,916 42.55 210,903 2001 6,317,482.77 3,135,089 2,625,851 7,482,121 43.46 172,161 2002 4,417,790.88 2,090,216 1,750,699 5,317,766 44.37 119,850 2003 5,892,297.35 2,651,722 2,220,999 7,206,677 45.28 159,158 2004 6,789,589.04 2,896,928 2,426,375 8,436,967 46.20 182,618 2005 6,036,005.21 2,432,752 2,037,596 7,620,012 47.13 161,681 2006 7,979,223.16 3,027,509 2,535,746 10,231,011 48.06 212,880 2007 10,302,928.29 3,663,227 3,068,203 13,416,482 49.00 273,806 2008 11,380,314.04 3,774,623 3,161,505 15,046,997 49.94 301,302 2009 17,540,915.88 5,399,234 4,522,228 23,543,237 50.88 462,721 2010 14,503,542.04 4,110,652 3,442,952 19,762,715 51.84 381,225 2011 15,787,509.39 4,093,638 3,428,702 21,831,313 52.79 413,550 2012 18,671,542.32 4,386,468 3,673,967 26,200,501 53.75 487,451 2013 34,045,813.12 7,168,142 6,003,809 48,469,492 54.71 885,935 2014 25,441,305.89 4,736,154 3,966,853 36,739,236 55.67 659,947 2015 29,493,654.46 4,763,815 3,990,021 43,199,826 56.64 762,709 2016 15,642,961.95 2,141,459 1,793,618 23,235,121 57.61 403,317 2017 34,098,622.12 3,819,046 3,198,712 51,359,083 58.59 876,584 2018 23,980,094.19 2,094,901 1,754,623 36,613,528 59.56 614,734 2019 22,653,817.66 1,415,411 1,185,504 35,060,604 60.54 579,131 2020 24,143,848.04 907,422 760,028 37,870,129 61.52 615,574 2021 37,508,244.78 466,903 391,063 59,622,128 62.51 953,801 497,678,991.49 165,062,392 138,251,042 658,035,344 13,408,462 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 49.1 2.69 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-155 Attachment C J. Spanos, Avista Page 635 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 365.00 OVERHEAD CONDUCTORS AND DEVICES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-R3 NET SALVAGE PERCENT.. -55 1940 30,355.03 41,882 38,956 8,094 7.14 1,134 1941 49,204.66 67,549 62,830 13,437 7.43 1,808 1942 77,935.42 106,471 99,033 21,767 7.71 2,823 1943 42,161.38 57,297 53,294 12,056 8.01 1,505 1944 69,041.64 93,333 86,813 20,202 8.31 2,431 1945 60,550.42 81,392 75,706 18,147 8.63 2,103 1946 135,718.77 181,399 168,727 41,637 8.95 4,652 1947 182,366.81 242,270 225,345 57,324 9.29 6,171 1948 227,380.44 300,226 279,253 73,187 9.63 7,600 1949 315,971.89 414,486 385,531 104,225 9.99 10,433 1950 186,686.21 243,245 226,252 63,112 10.36 6,092 1951 324,037.71 419,195 389,911 112,347 10.75 10,451 1952 344,693.48 442,625 411,704 122,571 11.15 10,993 1953 377,087.76 480,535 446,966 137,520 11.56 11,896 1954 3,221.90 4,073 3,788 1,206 11.99 101 1955 398,011.15 498,944 464,088 152,829 12.43 12,295 1956 678,094.21 842,781 783,906 267,140 12.88 20,741 1957 450,146.21 554,428 515,696 182,031 13.35 13,635 1958 373,020.16 455,075 423,284 154,897 13.84 11,192 1959 292,398.58 353,301 328,620 124,598 14.33 8,695 1960 235,476.62 281,603 261,931 103,058 14.85 6,940 1961 538,526.86 637,206 592,692 242,025 15.38 15,736 1962 286,345.84 335,132 311,720 132,116 15.92 8,299 1963 326,630.50 377,916 351,515 154,762 16.48 9,391 1964 266,471.25 304,688 283,403 129,627 17.05 7,603 1965 442,405.56 499,738 464,827 220,902 17.63 12,530 1966 356,442.13 397,535 369,764 182,721 18.23 10,023 1967 312,565.27 344,051 320,016 164,460 18.84 8,729 1968 316,415.92 343,615 319,611 170,834 19.46 8,779 1969 417,933.12 447,478 416,218 231,578 20.10 11,521 1970 792,804.94 836,563 778,122 450,726 20.75 21,722 1971 893,304.11 928,555 863,687 520,934 21.41 24,331 1972 768,266.89 786,306 731,376 459,438 22.08 20,808 1973 1,325,884.16 1,335,520 1,242,222 812,898 22.76 35,716 1974 1,169,621.87 1,158,869 1,077,912 735,002 23.45 31,343 1975 1,537,582.41 1,497,422 1,392,814 990,439 24.16 40,995 1976 1,598,641.83 1,529,803 1,422,933 1,054,962 24.87 42,419 1977 1,457,255.30 1,369,500 1,273,829 984,917 25.59 38,488 1978 1,971,581.97 1,818,047 1,691,041 1,364,911 26.33 51,839 1979 2,039,269.70 1,844,493 1,715,639 1,445,229 27.07 53,389 1980 2,234,997.24 1,981,549 1,843,121 1,621,125 27.82 58,272 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-156 Attachment C J. Spanos, Avista Page 636 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 365.00 OVERHEAD CONDUCTORS AND DEVICES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-R3 NET SALVAGE PERCENT.. -55 1981 2,203,409.66 1,913,618 1,779,935 1,635,350 28.58 57,220 1982 2,253,482.44 1,915,715 1,781,886 1,711,012 29.35 58,297 1983 2,547,440.79 2,118,230 1,970,254 1,978,279 30.13 65,658 1984 2,830,502.61 2,300,952 2,140,211 2,247,068 30.91 72,697 1985 3,653,264.63 2,900,080 2,697,485 2,965,075 31.71 93,506 1986 4,056,177.30 3,142,594 2,923,057 3,364,018 32.51 103,476 1987 2,317,369.12 1,750,631 1,628,334 1,963,588 33.32 58,931 1988 151,446.18 111,448 103,662 131,080 34.14 3,839 1989 3,458,977.33 2,477,778 2,304,684 3,056,731 34.96 87,435 1990 3,065,889.92 2,134,799 1,985,665 2,766,464 35.80 77,276 1991 2,665,173.67 1,802,405 1,676,492 2,454,527 36.64 66,990 1992 1,953,063.96 1,281,223 1,191,719 1,835,530 37.49 48,961 1993 2,924,701.61 1,859,328 1,729,438 2,803,849 38.34 73,131 1994 2,082,559.61 1,280,761 1,191,289 2,036,678 39.21 51,943 1995 8,584,371.21 5,101,168 4,744,808 8,560,967 40.08 213,597 1996 4,452,456.74 2,553,484 2,375,101 4,526,207 40.95 110,530 1997 3,885,833.32 2,146,973 1,996,989 4,026,053 41.83 96,248 1998 4,152,490.97 2,206,191 2,052,070 4,384,291 42.72 102,629 1999 4,938,442.44 2,517,746 2,341,860 5,312,726 43.62 121,796 2000 5,762,074.87 2,814,048 2,617,463 6,313,753 44.52 141,818 2001 3,909,803.36 1,824,604 1,697,140 4,363,055 45.43 96,039 2002 2,664,581.42 1,185,669 1,102,840 3,027,261 46.34 65,327 2003 3,839,919.59 1,624,386 1,510,909 4,440,966 47.26 93,969 2004 3,627,635.06 1,455,021 1,353,375 4,269,459 48.18 88,615 2005 2,844,159.73 1,077,689 1,002,403 3,406,045 49.11 69,355 2006 4,221,664.94 1,505,024 1,399,885 5,143,696 50.05 102,771 2007 5,946,918.31 1,986,788 1,847,994 7,369,729 50.99 144,533 2008 8,224,664.54 2,563,414 2,384,337 10,363,893 51.93 199,574 2009 9,948,095.11 2,875,129 2,674,276 12,745,271 52.88 241,023 2010 11,353,205.60 3,024,125 2,812,864 14,784,605 53.83 274,654 2011 14,074,329.94 3,430,006 3,190,391 18,624,820 54.78 339,993 2012 11,074,953.36 2,445,494 2,274,655 14,891,523 55.74 267,160 2013 16,980,820.95 3,356,888 3,122,380 23,197,892 56.71 409,062 2014 9,480,311.89 1,657,097 1,541,335 13,153,148 57.67 228,076 2015 13,657,881.96 2,071,457 1,926,748 19,242,969 58.64 328,154 2016 15,295,808.42 1,965,909 1,828,573 21,879,930 59.61 367,051 2017 29,342,401.40 3,085,867 2,870,293 42,610,429 60.59 703,258 2018 12,873,696.41 1,055,978 982,209 18,972,020 61.56 308,187 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-157 Attachment C J. Spanos, Avista Page 637 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 365.00 OVERHEAD CONDUCTORS AND DEVICES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-R3 NET SALVAGE PERCENT.. -55 2019 12,593,302.95 738,818 687,205 18,832,415 62.54 301,126 2020 15,571,387.28 549,569 511,177 23,624,473 63.52 371,922 2021 20,330,124.75 237,598 221,000 31,290,694 64.51 485,052 319,701,302.67 108,981,798 101,368,487 394,168,533 7,856,503 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 50.2 2.46 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-158 Attachment C J. Spanos, Avista Page 638 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 366.00 UNDERGROUND CONDUIT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-S2.5 NET SALVAGE PERCENT.. -25 1909 86,553.15 102,832 108,191 1910 91,718.70 108,651 114,648 1911 48,590.04 57,374 60,738 1912 7,500.88 8,831 9,376 1913 5,331.69 6,258 6,665 1914 1,788.86 2,093 2,236 1915 79,049.23 92,214 98,812 1916 6,798.94 7,906 8,499 1917 5,650.45 6,550 7,063 1918 825.12 953 1,031 1921 5,814.89 6,656 7,269 1923 984.92 1,120 1,231 1924 302.51 343 378 1926 4,214.62 4,746 5,268 1927 21,305.92 23,908 26,632 1928 51,079.13 57,110 63,849 1929 91,756.92 102,238 114,696 1930 44,152.55 49,018 55,191 1931 788.76 872 986 1934 3,680.59 4,025 4,601 1936 14,351.19 15,568 17,866 73 8.59 8 1937 6,942.69 7,499 8,606 72 8.83 8 1938 3,645.23 3,921 4,500 57 9.06 6 1939 13.58 15 17 1940 3,751.02 3,999 4,589 100 9.56 10 1941 2,872.94 3,049 3,499 92 9.81 9 1944 11.93 12 14 1 10.61 1945 3,355.02 3,491 4,006 188 10.89 17 1946 409.87 424 487 25 11.18 2 1947 7,793.92 8,023 9,207 535 11.47 47 1948 24,596.79 25,179 28,896 1,850 11.77 157 1949 15,830.27 16,110 18,488 1,300 12.08 108 1950 46,159.80 46,701 53,594 4,106 12.39 331 1951 22,683.75 22,806 26,172 2,183 12.72 172 1952 25,962.69 25,938 29,767 2,686 13.05 206 1953 42,392.13 42,074 48,284 4,706 13.39 351 1954 11,563.55 11,399 13,082 1,372 13.74 100 1955 27,831.52 27,243 31,264 3,525 14.10 250 1956 7,040.82 6,842 7,852 949 14.47 66 1957 2,404.12 2,319 2,661 344 14.85 23 1958 10,146.92 9,710 11,143 1,541 15.24 101 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-159 Attachment C J. Spanos, Avista Page 639 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 366.00 UNDERGROUND CONDUIT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-S2.5 NET SALVAGE PERCENT.. -25 1959 3,130.86 2,972 3,411 503 15.64 32 1960 4,252.39 4,003 4,594 721 16.05 45 1961 23,877.29 22,284 25,573 4,274 16.47 260 1962 30.90 29 33 6 16.91 1963 23,721.03 21,737 24,946 4,705 17.35 271 1964 22,010.92 19,975 22,923 4,591 17.81 258 1965 17,535.88 15,752 18,077 3,843 18.29 210 1966 23,559.33 20,945 24,037 5,412 18.77 288 1967 6,935.67 6,099 6,999 1,671 19.27 87 1971 39,796.62 33,368 38,293 11,453 21.40 535 1972 39,704.34 32,863 37,714 11,916 21.96 543 1973 131,281.24 107,171 122,990 41,112 22.55 1,823 1974 210,312.17 169,262 194,246 68,644 23.15 2,965 1975 239,336.94 189,812 217,830 81,341 23.76 3,423 1976 185,654.72 144,989 166,390 65,678 24.39 2,693 1977 343,889.31 264,331 303,348 126,514 25.03 5,054 1978 315,290.07 238,347 273,529 120,584 25.69 4,694 1979 378,239.93 280,990 322,466 150,334 26.37 5,701 1980 366,409.28 267,337 306,798 151,214 27.06 5,588 1981 355,552.44 254,629 292,214 152,227 27.76 5,484 1982 377,238.61 264,939 304,046 167,502 28.48 5,881 1983 384,018.75 264,234 303,237 176,786 29.22 6,050 1984 939,325.12 632,776 726,178 447,978 29.97 14,948 1985 630,836.05 415,626 476,975 311,570 30.74 10,136 1986 728,748.31 469,205 538,463 372,472 31.52 11,817 1987 587,019.86 369,030 423,501 310,274 32.31 9,603 1988 1,149,531.80 704,534 808,528 628,387 33.13 18,967 1989 731,587.66 436,840 501,321 413,164 33.95 12,170 1990 1,078,260.45 626,429 718,894 628,932 34.79 18,078 1991 1,139,360.03 643,297 738,252 685,948 35.64 19,247 1992 2,588,113.10 1,418,480 1,627,857 1,607,284 36.50 44,035 1993 2,496,171.46 1,326,341 1,522,118 1,598,096 37.37 42,764 1994 4,376,586.52 2,250,550 2,582,746 2,887,987 38.26 75,483 1995 3,766,210.87 1,871,524 2,147,774 2,559,990 39.16 65,373 1996 2,781,799.15 1,334,186 1,531,121 1,946,128 40.06 48,580 1997 3,817,567.13 1,763,430 2,023,724 2,748,235 40.98 67,063 1998 3,265,467.33 1,449,990 1,664,018 2,417,816 41.91 57,691 1999 2,909,798.15 1,240,010 1,423,044 2,214,204 42.84 51,685 2000 3,573,705.95 1,458,340 1,673,601 2,793,531 43.78 63,808 2001 2,541,834.61 990,839 1,137,093 2,040,200 44.73 45,611 2002 2,207,022.68 819,578 940,553 1,818,225 45.69 39,795 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-160 Attachment C J. Spanos, Avista Page 640 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 366.00 UNDERGROUND CONDUIT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-S2.5 NET SALVAGE PERCENT.. -25 2003 2,555,904.83 901,947 1,035,080 2,159,801 46.65 46,298 2004 5,697,180.29 1,904,140 2,185,204 4,936,271 47.62 103,660 2005 2,992,626.88 943,837 1,083,154 2,657,630 48.60 54,684 2006 4,418,995.84 1,311,227 1,504,773 4,018,972 49.57 81,077 2007 3,986,918.90 1,107,118 1,270,536 3,713,113 50.56 73,440 2008 5,515,828.28 1,427,772 1,638,521 5,256,264 51.54 101,984 2009 3,695,622.05 886,256 1,017,073 3,602,455 52.53 68,579 2010 3,022,098.24 667,204 765,688 3,011,935 53.52 56,277 2011 4,756,647.68 959,535 1,101,169 4,844,641 54.51 88,876 2012 3,018,396.61 550,857 632,167 3,140,829 55.51 56,581 2013 2,661,270.01 434,519 498,657 2,827,931 56.51 50,043 2014 4,169,698.71 601,375 690,142 4,521,981 57.50 78,643 2015 6,753,595.19 844,199 968,809 7,473,185 58.50 127,747 2016 4,844,866.03 512,466 588,109 5,467,974 59.50 91,899 2017 8,866,215.72 767,260 880,513 10,202,257 60.50 168,632 2018 5,237,880.61 352,575 404,617 6,142,734 61.50 99,882 2019 5,729,586.36 275,450 316,108 6,845,875 62.50 109,534 2020 10,635,712.27 306,840 352,132 12,942,508 63.50 203,819 2021 10,085,164.95 96,944 111,254 12,495,202 64.50 193,724 144,282,581.99 38,624,614 44,284,515 136,068,713 2,626,090 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 51.8 1.82 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-161 Attachment C J. Spanos, Avista Page 641 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 367.00 UNDERGROUND CONDUCTORS AND DEVICES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 40-S1.5 NET SALVAGE PERCENT.. -25 1973 540.71 533 676 1982 378,544.12 334,893 469,486 3,694 11.69 316 1983 1,335,642.42 1,164,513 1,632,529 37,024 12.10 3,060 1984 1,909,108.57 1,639,447 2,298,339 88,047 12.52 7,033 1985 2,745,120.08 2,320,484 3,253,084 178,316 12.95 13,770 1986 2,125,743.94 1,767,689 2,478,121 179,059 13.39 13,373 1987 1,643,648.35 1,343,169 1,882,987 171,573 13.85 12,388 1989 1,972,187.09 1,552,481 2,176,421 288,813 14.81 19,501 1990 2,594,731.30 2,001,997 2,806,597 436,817 15.31 28,531 1991 2,887,072.00 2,181,544 3,058,304 550,536 15.82 34,800 1992 4,697,150.88 3,471,488 4,866,675 1,004,764 16.35 61,453 1993 5,631,961.17 4,065,572 5,699,521 1,340,430 16.90 79,315 1994 6,963,498.25 4,904,914 6,876,193 1,828,180 17.46 104,707 1995 6,354,346.35 4,360,670 6,113,218 1,829,715 18.04 101,425 1996 5,261,337.05 3,511,942 4,923,387 1,653,284 18.64 88,695 1997 5,190,676.53 3,364,207 4,716,278 1,772,068 19.26 92,008 1998 4,410,823.32 2,771,927 3,885,961 1,627,568 19.89 81,828 1999 5,129,956.13 3,118,051 4,371,192 2,041,253 20.55 99,331 2000 3,685,198.35 2,162,751 3,031,958 1,574,540 21.22 74,201 2001 2,547,218.81 1,439,975 2,018,699 1,165,325 21.91 53,187 2002 2,335,241.35 1,267,598 1,777,044 1,142,008 22.63 50,464 2003 3,422,439.76 1,779,669 2,494,916 1,783,134 23.36 76,333 2004 6,411,099.07 3,183,511 4,462,960 3,550,914 24.11 147,280 2005 4,995,637.28 2,360,439 3,309,097 2,935,450 24.88 117,984 2006 7,546,806.68 3,379,554 4,737,793 4,695,715 25.67 182,926 2007 8,956,832.22 3,781,463 5,301,228 5,894,812 26.49 222,530 2008 9,253,787.62 3,666,813 5,140,501 6,426,734 27.32 235,239 2009 8,407,018.50 3,107,970 4,357,059 6,151,714 28.17 218,378 2010 7,118,496.76 2,440,310 3,421,068 5,477,053 29.03 188,669 2011 7,221,323.09 2,274,717 3,188,923 5,837,731 29.92 195,111 2012 5,610,336.31 1,609,465 2,256,307 4,756,613 30.82 154,335 2013 10,568,348.45 2,727,955 3,824,317 9,386,119 31.74 295,719 2014 9,800,393.12 2,244,903 3,147,127 9,103,364 32.67 278,646 2015 14,723,851.19 2,940,169 4,121,819 14,282,995 33.61 424,963 2016 8,637,409.39 1,465,660 2,054,707 8,742,055 34.57 252,880 2017 14,297,464.33 1,992,709 2,793,576 15,078,254 35.54 424,262 2018 11,896,374.67 1,293,731 1,813,680 13,056,788 36.52 357,524 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-162 Attachment C J. Spanos, Avista Page 642 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 367.00 UNDERGROUND CONDUCTORS AND DEVICES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 40-S1.5 NET SALVAGE PERCENT.. -25 2019 11,436,776.96 889,924 1,247,584 13,048,387 37.51 347,864 2020 12,249,994.67 574,219 804,997 14,507,496 38.50 376,818 2021 19,789,262.21 309,207 433,477 24,303,101 39.50 615,268 252,143,399.05 90,768,233 127,247,806 187,931,443 6,132,115 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 30.6 2.43 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-163 Attachment C J. Spanos, Avista Page 643 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 368.00 LINE TRANSFORMERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 50-R2.5 NET SALVAGE PERCENT.. -10 1947 24,394.17 24,370 26,834 1948 101,747.12 101,155 111,922 1949 44,684.81 44,208 49,153 1950 111,049.15 109,303 122,154 1951 99,818.05 97,744 109,800 1952 85,117.53 82,918 93,577 52 5.72 9 1953 102,932.61 99,752 112,575 651 5.95 109 1954 134,332.14 129,472 146,115 1,650 6.19 267 1955 184,035.21 176,365 199,036 3,403 6.44 528 1956 188,329.46 179,444 202,511 4,651 6.69 695 1957 181,838.72 172,259 194,403 5,620 6.94 810 1958 135,078.06 127,190 143,540 5,046 7.20 701 1959 163,963.01 153,414 173,135 7,224 7.47 967 1960 137,689.49 127,982 144,434 7,024 7.75 906 1961 134,317.07 123,991 139,930 7,819 8.04 973 1962 111,725.34 102,399 115,562 7,336 8.34 880 1963 95,904.50 87,223 98,435 7,060 8.66 815 1964 114,303.88 103,127 116,384 9,350 8.99 1,040 1965 118,818.16 106,311 119,977 10,723 9.33 1,149 1966 140,744.12 124,846 140,895 13,924 9.68 1,438 1967 280,355.27 246,343 278,010 30,381 10.06 3,020 1968 195,300.44 169,931 191,775 23,055 10.45 2,206 1969 243,505.41 209,731 236,692 31,164 10.85 2,872 1970 291,896.36 248,649 280,612 40,474 11.28 3,588 1971 689,049.33 580,290 654,885 103,069 11.72 8,794 1972 751,170.64 625,004 705,347 120,941 12.18 9,929 1973 1,187,741.01 975,705 1,101,130 205,385 12.66 16,223 1974 1,287,937.46 1,044,131 1,178,352 238,379 13.15 18,128 1975 1,649,545.48 1,318,779 1,488,305 326,195 13.66 23,880 1976 1,871,364.61 1,474,298 1,663,816 394,685 14.19 27,814 1977 2,223,799.69 1,725,535 1,947,349 498,831 14.73 33,865 1978 2,650,004.63 2,023,597 2,283,726 631,279 15.29 41,287 1979 3,055,629.33 2,294,350 2,589,284 771,908 15.87 48,639 1980 2,258,777.41 1,666,707 1,880,959 603,696 16.46 36,677 1981 2,826,164.02 2,047,443 2,310,638 798,142 17.07 46,757 1982 2,053,702.91 1,459,813 1,647,469 611,604 17.69 34,573 1983 3,328,453.62 2,319,799 2,618,005 1,043,294 18.32 56,948 1984 4,055,929.04 2,768,821 3,124,747 1,336,775 18.97 70,468 1985 3,670,454.55 2,452,378 2,767,626 1,269,874 19.63 64,690 1986 3,362,183.19 2,196,850 2,479,251 1,219,151 20.30 60,057 1987 2,021,948.79 1,290,448 1,456,333 767,811 20.99 36,580 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-164 Attachment C J. Spanos, Avista Page 644 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 368.00 LINE TRANSFORMERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 50-R2.5 NET SALVAGE PERCENT.. -10 1988 1,372,743.00 855,274 965,218 544,799 21.68 25,129 1989 2,670,373.42 1,622,038 1,830,548 1,106,863 22.39 49,436 1990 2,643,033.57 1,563,566 1,764,559 1,142,778 23.11 49,450 1991 3,139,777.99 1,807,005 2,039,292 1,414,464 23.84 59,332 1992 3,750,785.97 2,097,590 2,367,231 1,758,634 24.58 71,547 1993 3,998,968.15 2,170,400 2,449,401 1,949,464 25.33 76,963 1994 4,613,795.86 2,426,949 2,738,928 2,336,247 26.09 89,546 1995 10,334,818.16 5,261,249 5,937,572 5,430,728 26.86 202,186 1996 4,517,432.43 2,223,209 2,508,998 2,460,178 27.63 89,040 1997 3,991,832.43 1,895,162 2,138,781 2,252,235 28.42 79,248 1998 3,695,473.53 1,689,423 1,906,595 2,158,426 29.22 73,868 1999 3,420,216.42 1,503,390 1,696,648 2,065,590 30.02 68,807 2000 3,073,670.06 1,295,613 1,462,161 1,918,876 30.84 62,220 2001 2,785,122.55 1,123,741 1,268,196 1,795,439 31.66 56,710 2002 2,710,349.88 1,044,081 1,178,296 1,803,089 32.49 55,497 2003 3,697,405.21 1,355,986 1,530,295 2,536,851 33.33 76,113 2004 4,949,848.37 1,722,745 1,944,200 3,500,633 34.18 102,418 2005 6,053,303.07 1,993,595 2,249,868 4,408,765 35.03 125,857 2006 9,976,408.56 3,096,877 3,494,974 7,479,075 35.89 208,389 2007 12,669,078.64 3,690,249 4,164,623 9,771,364 36.76 265,815 2008 9,763,558.29 2,654,907 2,996,190 7,743,724 37.64 205,731 2009 11,995,818.95 3,029,664 3,419,121 9,776,280 38.52 253,798 2010 10,794,584.18 2,514,922 2,838,210 9,035,833 39.41 229,278 2011 16,089,831.67 3,433,570 3,874,949 13,823,866 40.30 343,024 2012 10,411,869.19 2,015,738 2,274,857 9,178,199 41.20 222,772 2013 23,381,539.10 4,058,568 4,580,289 21,139,404 42.11 502,004 2014 11,773,356.47 1,807,917 2,040,321 10,910,371 43.02 253,612 2015 16,782,592.89 2,241,147 2,529,243 15,931,609 43.93 362,659 2016 8,305,552.69 939,192 1,059,923 8,076,185 44.86 180,031 2017 15,691,938.50 1,456,840 1,644,114 15,617,018 45.78 341,132 2018 8,336,014.08 603,361 680,922 8,488,693 46.71 181,732 2019 6,525,939.93 337,391 380,762 6,797,772 47.65 142,660 2020 7,371,083.39 228,651 258,044 7,850,148 48.59 161,559 2021 14,426,589.63 149,171 168,347 15,700,902 49.53 316,998 308,080,442.02 97,321,256 109,826,359 229,062,127 6,242,843 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 36.7 2.03 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-165 Attachment C J. Spanos, Avista Page 645 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 369.10 SERVICES - OVERHEAD CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 70-R4 NET SALVAGE PERCENT.. -35 1943 5,887.03 7,154 7,947 1944 20,512.90 24,800 27,692 1945 20,427.87 24,564 27,578 1946 32,258.39 38,572 43,549 1947 87,570.19 104,101 118,220 1948 64,473.70 76,160 87,039 1949 73,039.23 85,715 98,603 1950 49,661.61 57,878 67,043 1951 81,901.11 94,740 110,566 1952 133,649.02 153,415 180,426 1954 192,141.39 216,851 259,391 1955 226,018.99 252,775 302,571 2,555 12.01 213 1956 265,994.83 294,611 352,648 6,445 12.57 513 1957 241,079.29 264,317 316,387 9,070 13.15 690 1958 174,340.44 189,095 226,346 9,014 13.76 655 1959 259,088.29 277,916 332,665 17,104 14.38 1,189 1960 119,257.20 126,452 151,363 9,634 15.02 641 1961 226,967.58 237,814 284,663 21,743 15.67 1,388 1962 219,628.58 227,328 272,111 24,388 16.33 1,493 1963 220,659.94 225,503 269,926 27,965 17.01 1,644 1964 251,044.49 253,213 303,095 35,815 17.70 2,023 1965 251,390.89 250,220 299,512 39,866 18.39 2,168 1966 299,795.44 294,291 352,265 52,459 19.10 2,747 1967 284,105.87 275,000 329,174 54,369 19.81 2,745 1968 19,231.04 18,344 21,958 4,004 20.54 195 1969 147,710.23 138,789 166,130 33,279 21.28 1,564 1970 141,025.93 130,469 156,171 34,214 22.03 1,553 1971 213,643.00 194,558 232,885 55,533 22.78 2,438 1972 259,732.98 232,674 278,510 72,130 23.55 3,063 1973 274,263.65 241,566 289,154 81,102 24.33 3,333 1974 442,882.41 383,332 458,847 139,044 25.12 5,535 1975 523,463.38 444,902 532,546 174,130 25.93 6,715 1976 651,804.27 543,800 650,927 229,009 26.74 8,564 1977 785,185.70 642,668 769,271 290,730 27.56 10,549 1978 848,266.35 680,717 814,816 330,344 28.39 11,636 1979 922,839.40 725,611 868,554 377,279 29.23 12,907 1980 770,743.57 593,233 710,098 330,406 30.09 10,981 1981 784,700.78 590,967 707,385 351,961 30.95 11,372 1982 634,996.83 467,568 559,677 297,569 31.82 9,352 1983 804,344.78 578,614 692,599 393,266 32.70 12,026 1984 977,755.92 686,569 821,821 498,149 33.59 14,830 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-166 Attachment C J. Spanos, Avista Page 646 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 369.10 SERVICES - OVERHEAD CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 70-R4 NET SALVAGE PERCENT.. -35 1985 1,021,611.57 699,835 837,700 541,476 34.48 15,704 1986 906,780.70 605,258 724,492 499,662 35.39 14,119 1987 828,125.75 538,224 644,252 473,718 36.30 13,050 1988 903,076.75 570,917 683,386 535,768 37.22 14,395 1989 792,294.41 486,817 582,718 486,879 38.14 12,766 1990 946,200.24 564,419 675,608 601,762 39.07 15,402 1991 1,079,179.62 624,176 747,137 709,755 40.01 17,739 1992 1,350,910.03 756,847 905,943 917,786 40.95 22,412 1993 1,433,726.66 776,980 930,042 1,005,489 41.90 23,997 1994 1,645,563.48 861,302 1,030,976 1,190,535 42.86 27,777 1995 2,626,389.08 1,326,560 1,587,888 1,957,737 43.81 44,687 1996 1,676,357.49 815,366 975,990 1,287,093 44.78 28,743 1997 1,615,850.40 756,007 904,938 1,276,460 45.74 27,907 1998 1,446,210.00 649,578 777,543 1,174,840 46.71 25,152 1999 1,281,150.24 551,485 660,126 1,069,427 47.68 22,429 2000 1,530,125.42 629,740 753,797 1,311,872 48.66 26,960 2001 1,400,746.06 550,018 658,370 1,232,637 49.64 24,832 2002 1,623,956.48 606,972 726,543 1,465,798 50.62 28,957 2003 1,655,001.24 587,295 702,990 1,531,262 51.60 29,676 2004 1,140,634.96 382,978 458,423 1,081,434 52.59 20,563 2005 591,833.77 187,528 224,470 574,506 53.57 10,724 2006 957,387.37 285,081 341,241 951,232 54.56 17,435 2007 810,928.71 225,990 270,509 824,245 55.55 14,838 2008 750,967.85 194,945 233,349 780,458 56.54 13,804 2009 879,424.26 211,326 252,956 934,267 57.54 16,237 2010 975,481.78 215,787 258,296 1,058,604 58.53 18,087 2011 702,184.80 141,918 169,875 778,074 59.52 13,072 2012 5,145,288.42 940,716 1,126,034 5,820,105 60.52 96,168 2013 791,120.31 129,379 154,866 913,146 61.52 14,843 2014 263,772.71 38,102 45,608 310,485 62.51 4,967 2015 3,147,992.55 393,998 471,615 3,778,175 63.51 59,489 2016 1,586,065.76 167,933 201,015 1,940,174 64.51 30,076 2017 1,408,674.62 121,976 146,005 1,755,706 65.51 26,801 2018 1,388,767.23 93,742 112,209 1,762,627 66.50 26,506 2019 1,421,240.53 68,516 82,014 1,836,661 67.50 27,210 2020 2,295,790.03 66,418 79,502 3,019,815 68.50 44,085 2021 3,487,170.26 33,613 40,235 4,667,445 69.50 67,157 66,511,466.03 28,204,608 33,730,790 56,059,690 1,103,488 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 50.8 1.66 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-167 Attachment C J. Spanos, Avista Page 647 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 369.20 SERVICES - UNDERGROUND - SPOKANE NETWORK CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 70-R4 NET SALVAGE PERCENT.. -35 1956 4,113.93 4,557 5,264 290 12.57 23 1957 5,598.31 6,138 7,091 467 13.15 36 1958 4,041.74 4,384 5,065 391 13.76 28 1959 5,983.63 6,418 7,414 664 14.38 46 1960 3,309.61 3,509 4,054 414 15.02 28 1961 5,222.56 5,472 6,321 729 15.67 47 1962 5,047.74 5,225 6,036 778 16.33 48 1963 5,062.93 5,174 5,977 858 17.01 50 1964 5,750.73 5,800 6,700 1,063 17.70 60 1965 5,749.30 5,723 6,611 1,151 18.39 63 1966 6,846.16 6,720 7,763 1,479 19.10 77 1967 6,478.93 6,271 7,244 1,503 19.81 76 1968 1,840.37 1,755 2,027 457 20.54 22 1969 3,362.37 3,159 3,649 890 21.28 42 1971 3,576.87 3,257 3,763 1,066 22.78 47 1972 1,801.07 1,613 1,863 568 23.55 24 1973 6,303.46 5,552 6,414 2,096 24.33 86 1974 10,336.04 8,946 10,335 3,619 25.12 144 1975 11,855.24 10,076 11,640 4,365 25.93 168 1976 14,753.61 12,309 14,220 5,697 26.74 213 1977 17,764.72 14,540 16,797 7,185 27.56 261 1978 19,186.66 15,397 17,787 8,115 28.39 286 1979 20,866.00 16,407 18,954 9,215 29.23 315 1980 17,422.59 13,410 15,492 8,028 30.09 267 1981 17,733.02 13,355 15,428 8,512 30.95 275 1982 14,347.34 10,564 12,204 7,165 31.82 225 1983 18,171.03 13,072 15,101 9,430 32.70 288 1984 22,085.19 15,508 17,915 11,900 33.59 354 1985 23,073.73 15,806 18,260 12,890 34.48 374 1986 20,479.68 13,670 15,792 11,856 35.39 335 1987 18,700.69 12,154 14,041 11,205 36.30 309 1988 20,391.24 12,891 14,892 12,636 37.22 339 1989 17,887.58 10,991 12,697 11,451 38.14 300 1990 21,360.49 12,742 14,720 14,117 39.07 361 1991 19,193.74 11,101 12,824 13,088 40.01 327 1992 30,492.28 17,083 19,735 21,430 40.95 523 1993 32,359.59 17,537 20,259 23,426 41.90 559 1994 37,138.31 19,439 22,456 27,681 42.86 646 1995 59,270.66 29,937 34,584 45,431 43.81 1,037 1996 37,830.68 18,401 21,257 29,814 44.78 666 1997 36,464.33 17,061 19,709 29,518 45.74 645 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-168 Attachment C J. Spanos, Avista Page 648 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 369.20 SERVICES - UNDERGROUND - SPOKANE NETWORK CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 70-R4 NET SALVAGE PERCENT.. -35 1998 32,634.23 14,658 16,933 27,123 46.71 581 1999 28,908.87 12,444 14,376 24,651 47.68 517 2000 34,525.96 14,210 16,416 30,194 48.66 621 2001 31,603.97 12,410 14,336 28,329 49.64 571 2002 26,482.81 9,898 11,434 24,318 50.62 480 2003 37,335.56 13,249 15,306 35,097 51.60 680 2004 106,927.24 35,902 41,475 102,877 52.59 1,956 2005 206,025.91 65,281 75,414 202,721 53.57 3,784 2006 188,389.28 56,097 64,805 189,521 54.56 3,474 2007 303,519.03 84,585 97,715 312,036 55.55 5,617 2008 375,741.21 97,539 112,680 394,571 56.54 6,979 2009 342,370.18 82,272 95,043 367,157 57.54 6,381 2010 277,657.60 61,421 70,955 303,883 58.53 5,192 2011 175,415.55 35,453 40,956 195,855 59.52 3,291 2012 430,432.48 78,696 90,912 490,172 60.52 8,099 2013 17,299.72 2,829 3,268 20,087 61.52 327 2014 560,636.11 80,984 93,555 663,304 62.51 10,611 2015 205,593.59 25,732 29,726 247,825 63.51 3,902 2016 288,562.09 30,553 35,296 354,263 64.51 5,492 2017 574,650.96 49,758 57,482 718,297 65.51 10,965 2018 838,970.05 56,630 65,421 1,067,189 66.50 16,048 2019 937,897.13 45,215 52,233 1,213,928 67.50 17,984 2020 1,039,616.86 30,077 34,746 1,368,737 68.50 19,982 2021 900,441.67 8,679 10,026 1,205,570 69.50 17,346 8,600,892.21 1,437,696 1,660,864 9,950,340 160,900 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 61.8 1.87 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-169 Attachment C J. Spanos, Avista Page 649 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 369.30 SERVICES - UNDERGROUND - OTHER CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 70-R4 NET SALVAGE PERCENT.. -35 1968 108,771.90 103,754 127,713 19,129 20.54 931 1969 183,425.62 172,347 212,146 35,479 21.28 1,667 1970 195,415.26 180,787 222,535 41,276 22.03 1,874 1971 267,525.13 243,627 299,886 61,273 22.78 2,690 1972 327,263.11 293,169 360,868 80,937 23.55 3,437 1973 352,335.30 310,330 381,992 93,661 24.33 3,850 1974 580,891.34 502,784 618,888 165,315 25.12 6,581 1975 478,717.49 406,871 500,826 145,443 25.93 5,609 1976 832,092.64 694,215 854,524 268,801 26.74 10,052 1977 1,004,504.63 822,179 1,012,038 344,043 27.56 12,483 1978 1,087,731.94 872,884 1,074,452 393,986 28.39 13,878 1979 1,185,205.47 931,904 1,147,101 452,926 29.23 15,495 1980 992,885.15 764,213 940,686 399,709 30.09 13,284 1981 1,011,127.62 761,491 937,336 427,686 30.95 13,819 1982 818,800.83 602,908 742,132 363,249 31.82 11,416 1983 1,039,378.28 747,688 920,345 482,816 32.70 14,765 1984 1,216,428.49 854,163 1,051,407 590,771 33.59 17,588 1985 1,320,753.95 904,757 1,113,685 669,333 34.48 19,412 1986 1,172,609.96 782,694 963,435 619,588 35.39 17,507 1987 1,013,925.52 658,981 811,154 557,645 36.30 15,362 1988 1,169,446.90 739,314 910,037 668,716 37.22 17,967 1989 987,379.42 606,684 746,780 586,182 38.14 15,369 1990 1,221,944.72 728,903 897,222 752,403 39.07 19,258 1991 1,395,927.07 807,377 993,818 890,684 40.01 22,262 1992 1,751,974.49 981,544 1,208,204 1,156,962 40.95 28,253 1993 1,859,910.35 1,007,942 1,240,697 1,270,182 41.90 30,315 1994 2,135,165.87 1,117,564 1,375,633 1,506,841 42.86 35,157 1995 3,409,593.17 1,722,148 2,119,829 2,483,122 43.81 56,679 1996 2,176,572.68 1,058,666 1,303,135 1,635,238 44.78 36,517 1997 2,098,630.87 981,885 1,208,623 1,624,529 45.74 35,517 1998 1,878,467.12 843,729 1,038,564 1,497,367 46.71 32,057 1999 1,664,257.28 716,398 881,830 1,364,917 47.68 28,627 2000 1,988,373.82 818,337 1,007,309 1,676,996 48.66 34,464 2001 1,820,380.63 714,792 879,853 1,577,661 49.64 31,782 2002 2,110,847.54 788,952 971,138 1,878,506 50.62 37,110 2003 2,146,487.76 761,705 937,599 1,960,159 51.60 37,988 2004 3,144,505.07 1,055,794 1,299,599 2,945,483 52.59 56,008 2005 3,398,083.74 1,076,712 1,325,348 3,262,065 53.57 60,894 2006 4,503,052.29 1,340,872 1,650,508 4,428,613 54.56 81,170 2007 4,310,903.60 1,201,365 1,478,786 4,340,934 55.55 78,145 2008 3,896,780.62 1,011,571 1,245,164 4,015,490 56.54 71,020 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-170 Attachment C J. Spanos, Avista Page 650 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 369.30 SERVICES - UNDERGROUND - OTHER CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 70-R4 NET SALVAGE PERCENT.. -35 2009 3,922,655.23 942,614 1,160,284 4,135,301 57.54 71,868 2010 3,821,319.16 845,318 1,040,520 4,118,261 58.53 70,362 2011 2,639,590.25 533,484 656,677 2,906,770 59.52 48,837 2012 3,529,477.37 645,296 794,309 3,970,485 60.52 65,606 2013 3,084,077.30 504,367 620,836 3,542,668 61.52 57,586 2014 5,291,148.75 764,306 940,800 6,202,251 62.51 99,220 2015 5,576,193.43 697,908 859,070 6,668,791 63.51 105,004 2016 3,796,467.25 401,972 494,796 4,630,435 64.51 71,779 2017 6,731,358.90 582,862 717,457 8,369,878 65.51 127,765 2018 4,901,527.45 330,853 407,254 6,209,808 66.50 93,381 2019 5,553,042.24 267,704 329,522 7,167,085 67.50 106,179 2020 6,261,856.10 181,159 222,993 8,230,513 68.50 120,153 2021 6,836,447.46 65,897 81,114 9,148,090 69.50 131,627 126,203,635.53 38,457,740 47,338,457 123,036,451 2,217,626 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 55.5 1.76 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-171 Attachment C J. Spanos, Avista Page 651 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 370.10 METERS - IDAHO CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 INTERIM SURVIVOR CURVE.. IOWA 33-L1.5 PROBABLE RETIREMENT YEAR.. 12-2028 NET SALVAGE PERCENT.. -2 1947 1,068.48 959 957 133 3.96 34 1948 8,813.47 7,892 7,878 1,112 4.03 276 1949 3,629.12 3,242 3,236 466 4.10 114 1950 7,352.17 6,551 6,539 960 4.17 230 1951 20,164.70 17,930 17,898 2,670 4.23 631 1952 16,030.36 14,218 14,193 2,158 4.30 502 1953 20,719.26 18,338 18,305 2,829 4.36 649 1954 21,787.18 19,235 19,201 3,022 4.43 682 1955 35,072.64 30,899 30,844 4,930 4.49 1,098 1956 21,428.41 18,837 18,804 3,053 4.55 671 1957 17,232.46 15,116 15,089 2,488 4.61 540 1958 12,546.77 10,985 10,965 1,833 4.66 393 1959 30,390.48 26,550 26,503 4,495 4.72 952 1960 30,432.39 26,536 26,489 4,552 4.77 954 1961 29,146.84 25,366 25,321 4,409 4.82 915 1962 31,261.89 27,144 27,096 4,791 4.88 982 1963 28,516.59 24,712 24,668 4,419 4.93 896 1964 24,250.10 20,974 20,937 3,798 4.98 763 1965 27,318.55 23,588 23,546 4,319 5.02 860 1966 35,842.79 30,884 30,829 5,731 5.07 1,130 1967 29,138.86 25,055 25,010 4,712 5.12 920 1968 30,996.76 26,606 26,559 5,058 5.16 980 1969 43,375.89 37,149 37,083 7,160 5.21 1,374 1970 34,277.69 29,301 29,249 5,714 5.25 1,088 1971 59,159.08 50,475 50,385 9,957 5.29 1,882 1972 69,932.68 59,546 59,440 11,891 5.33 2,231 1973 65,069.65 55,292 55,194 11,177 5.37 2,081 1974 88,566.06 75,098 74,964 15,373 5.41 2,842 1975 94,028.45 79,584 79,442 16,467 5.44 3,027 1976 123,503.30 104,292 104,107 21,866 5.48 3,990 1977 150,840.16 127,074 126,848 27,009 5.52 4,893 1978 165,314.78 138,967 138,720 29,901 5.55 5,388 1979 169,102.47 141,843 141,591 30,894 5.58 5,537 1980 113,240.13 94,763 94,594 20,911 5.61 3,727 1981 162,070.19 135,294 135,053 30,259 5.64 5,365 1982 365,486.51 304,325 303,784 69,012 5.67 12,171 1983 304,840.78 253,234 252,784 58,154 5.69 10,220 1984 252,714.82 209,332 208,960 48,809 5.72 8,533 1985 358,739.57 296,391 295,864 70,050 5.74 12,204 1986 205,614.48 169,323 169,022 40,705 5.77 7,055 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-172 Attachment C J. Spanos, Avista Page 652 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 370.10 METERS - IDAHO CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 INTERIM SURVIVOR CURVE.. IOWA 33-L1.5 PROBABLE RETIREMENT YEAR.. 12-2028 NET SALVAGE PERCENT.. -2 1987 135,429.44 111,190 110,992 27,146 5.79 4,688 1988 121,109.03 99,119 98,943 24,588 5.81 4,232 1989 146,024.74 119,043 118,831 30,114 5.84 5,157 1990 193,355.50 157,052 156,773 40,450 5.86 6,903 1991 209,964.35 169,870 169,568 44,596 5.88 7,584 1992 216,300.40 174,253 173,943 46,683 5.90 7,912 1993 248,966.74 199,543 199,188 54,758 5.93 9,234 1994 237,107.21 189,100 188,764 53,085 5.95 8,922 1995 366,042.11 290,208 289,692 83,671 5.98 13,992 1996 291,304.44 229,489 229,081 68,050 6.01 11,323 1997 307,522.18 240,609 240,181 73,492 6.04 12,168 1998 362,234.68 281,288 280,788 88,691 6.07 14,611 1999 255,824.26 197,042 196,692 64,249 6.10 10,533 2000 304,685.52 232,447 232,034 78,745 6.14 12,825 2001 206,528.00 155,936 155,659 55,000 6.18 8,900 2002 208,692.53 155,771 155,494 57,372 6.22 9,224 2003 275,659.62 203,153 202,792 78,381 6.26 12,521 2004 266,280.49 193,508 193,164 78,442 6.30 12,451 2005 32,510.84 23,242 23,201 9,960 6.35 1,569 2007 113,783.31 78,252 78,113 37,946 6.45 5,883 2008 11,195,068.40 7,520,648 7,507,272 3,911,698 6.50 601,800 2009 388,852.26 254,354 253,902 142,727 6.55 21,790 2010 270,795.04 171,900 171,594 104,617 6.59 15,875 2011 1,061,893.03 650,658 649,501 433,630 6.64 65,306 2012 264,046.18 155,316 155,040 114,287 6.68 17,109 2013 1,009,564.03 565,645 564,639 465,116 6.72 69,214 2015 420,435.36 206,904 206,536 222,308 6.79 32,741 2017 226,670.49 90,676 90,515 140,689 6.85 20,539 2019 870,983.91 234,192 233,775 654,629 6.90 94,874 2020 296.26 54 54 248 6.92 36 2021 989,452.11 67,821 67,700 941,541 6.94 135,669 24,506,399.42 16,201,183 16,172,372 8,824,155 1,364,365 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 6.5 5.57 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-173 Attachment C J. Spanos, Avista Page 653 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 370.30 METERS - WASHINGTON STANDARD CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 12-L2.5 NET SALVAGE PERCENT.. -2 1960 28.71 29 29 2008 216,184.23 149,762 169,055 51,453 3.85 13,364 2009 9,615.50 6,498 7,335 2,473 4.05 611 2010 1,500.21 991 1,119 411 4.23 97 2011 53.80 35 40 15 4.45 3 2012 169.68 105 119 54 4.72 11 2017 17,656.72 6,379 7,201 10,809 7.75 1,395 2019 1,190.68 248 280 934 9.55 98 2020 781,010.25 98,918 111,659 684,971 10.51 65,173 2021 70.46 3 4 68 11.50 6 1,027,480.24 262,968 296,841 751,189 80,758 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 9.3 7.86 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-174 Attachment C J. Spanos, Avista Page 654 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 370.40 METERS - WASHINGTON AMI CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 15-S2.5 NET SALVAGE PERCENT.. -2 2018 56,855,803.14 13,454,357 8,469,575 49,523,344 11.52 4,298,901 2019 112,062.72 19,051 11,993 102,311 12.50 8,185 2020 390,016.83 39,782 25,043 372,774 13.50 27,613 2021 2,089,520.02 71,037 44,718 2,086,593 14.50 143,903 59,447,402.71 13,584,227 8,551,329 52,085,022 4,478,602 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 11.6 7.53 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-175 Attachment C J. Spanos, Avista Page 655 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 371.00 INSTALLATIONS ON CUSTOMERS' PREMISES - CATALYST BUILDING CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 35-R3 NET SALVAGE PERCENT.. 0 2020 580,338.65 24,374 23,303 557,036 33.53 16,613 2021 24,647.86 345 329 24,318 34.51 705 604,986.51 24,719 23,632 581,354 17,318 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 33.6 2.86 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-176 Attachment C J. Spanos, Avista Page 656 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 371.01 ELECTRIC VEHICLE CHARGING STATION - RESIDENTIAL CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 10-S3 NET SALVAGE PERCENT.. 0 2016 172,288.09 91,830 77,919 94,369 4.67 20,207 2017 1,164,453.82 517,017 438,698 725,756 5.56 130,532 2018 511,377.50 178,471 151,436 359,942 6.51 55,291 2019 107,916.09 26,979 22,892 85,024 7.50 11,337 2021 616,425.72 30,821 26,152 590,274 9.50 62,134 2,572,461.22 845,118 717,097 1,855,364 279,501 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 6.6 10.87 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-177 Attachment C J. Spanos, Avista Page 657 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 371.02 ELECTRIC VEHICLE CHARGING STATION - MULTI-UNIT DWELLINGS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 10-S3 NET SALVAGE PERCENT.. 0 2016 165,896.47 88,423 106,800 59,097 4.67 12,655 165,896.47 88,423 106,800 59,097 12,655 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 4.7 7.63 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-178 Attachment C J. Spanos, Avista Page 658 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 373.10 STREET LIGHTING AND SIGNAL SYSTEMS - MERCURY VAPOR CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 33-S1 NET SALVAGE PERCENT.. -15 1967 17,053.70 17,722 19,612 1968 54,028.61 55,600 62,133 1969 33,714.17 34,342 38,771 1970 52,218.89 52,646 60,052 1971 113,838.46 113,538 130,914 1972 103,820.17 102,425 119,393 1973 55,183.64 53,846 63,461 1974 187,204.12 180,579 215,285 1975 95,843.49 91,382 110,220 1976 145,073.97 136,653 166,835 1977 167,127.08 155,446 192,196 1978 99,383.01 91,294 114,290 1979 111,716.11 101,260 128,474 1980 139,898.54 125,100 160,883 1981 152,439.02 134,401 175,305 1982 71,901.03 62,491 82,686 1983 102,640.62 87,884 118,037 1984 48,468.68 40,875 55,739 1985 42,473.79 35,243 48,845 1986 20,759.54 16,943 23,873 1987 24,213.38 19,424 27,845 1988 62,212.58 49,019 71,544 1989 37,756.41 29,210 43,420 1990 45,148.04 34,252 51,057 863 11.23 77 1991 35,050.55 26,054 38,837 1,471 11.67 126 1992 80,854.97 58,861 87,739 5,244 12.11 433 1993 251,189.29 178,835 266,574 22,294 12.57 1,774 1994 240,775.23 167,478 249,645 27,247 13.04 2,089 1995 273,296.05 185,526 276,548 37,742 13.52 2,792 1996 202,731.09 134,161 199,983 33,158 14.01 2,367 1997 235,502.20 151,663 226,071 44,757 14.52 3,082 1998 155,046.10 97,040 144,649 33,654 15.04 2,238 1999 146,046.18 88,659 132,157 35,796 15.58 2,298 2000 229,721.07 135,051 201,309 62,870 16.13 3,898 2001 125,966.17 71,596 106,722 38,139 16.69 2,285 2002 303,756.12 166,402 248,042 101,278 17.28 5,861 2003 178,807.05 94,215 140,439 65,189 17.88 3,646 2004 40,586.88 20,508 30,570 16,105 18.50 871 2006 20,394.62 9,382 13,985 9,469 19.80 478 2009 311.48 120 179 179 21.91 8 2014 128.29 32 48 100 25.91 4 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-179 Attachment C J. Spanos, Avista Page 659 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 373.10 STREET LIGHTING AND SIGNAL SYSTEMS - MERCURY VAPOR CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 33-S1 NET SALVAGE PERCENT.. -15 2018 30,307.42 3,633 5,415 29,439 29.56 996 2019 4,872.48 421 627 4,976 30.52 163 2021 2,716.64 47 70 3,054 32.50 94 4,542,176.93 3,411,259 4,650,479 573,024 35,580 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 16.1 0.78 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-180 Attachment C J. Spanos, Avista Page 660 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 373.20 STREET LIGHTING AND SIGNAL SYSTEMS - UNDERGROUND CONDUCTOR CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 33-S1 NET SALVAGE PERCENT.. -15 1964 66.47 71 76 1965 25,675.12 27,200 29,526 1966 224.56 236 258 1967 18,587.81 19,316 21,376 1968 27,911.48 28,723 32,098 1969 16,745.15 17,057 19,257 1970 25,364.10 25,571 29,169 1971 54,860.18 54,715 63,089 1972 45,775.83 45,161 52,642 1973 26,280.75 25,643 30,223 1974 87,898.47 84,788 101,083 1975 41,164.57 39,249 47,339 1976 66,850.21 62,970 76,770 108 5.97 18 1977 76,518.16 71,170 86,766 1,230 6.31 195 1978 45,323.33 41,634 50,758 1,364 6.64 205 1979 50,762.03 46,011 56,094 2,282 6.99 326 1980 63,319.29 56,621 69,029 3,788 7.34 516 1981 68,732.29 60,599 73,879 5,163 7.70 671 1982 32,447.23 28,201 34,381 2,933 8.06 364 1983 46,251.34 39,602 48,281 4,908 8.43 582 1984 21,850.20 18,427 22,465 2,663 8.80 303 1985 19,163.84 15,901 19,386 2,652 9.19 289 1986 9,374.00 7,651 9,328 1,452 9.58 152 1987 10,950.91 8,785 10,710 1,884 9.98 189 1988 27,974.33 22,042 26,872 5,298 10.39 510 1989 16,997.47 13,150 16,032 3,515 10.80 325 1990 20,325.27 15,420 18,799 4,575 11.23 407 1991 15,780.16 11,730 14,301 3,846 11.67 330 1992 35,316.56 25,710 31,344 9,270 12.11 765 1993 112,597.41 80,164 97,731 31,756 12.57 2,526 1994 107,851.88 75,019 91,459 32,571 13.04 2,498 1995 122,383.80 83,080 101,286 39,455 13.52 2,918 1996 90,780.39 60,076 73,241 31,156 14.01 2,224 1997 105,425.09 67,894 82,773 38,466 14.52 2,649 1998 69,456.15 43,471 52,997 26,878 15.04 1,787 1999 65,361.45 39,678 48,373 26,793 15.58 1,720 2000 102,883.92 60,485 73,740 44,577 16.13 2,764 2001 56,454.43 32,087 39,119 25,804 16.69 1,546 2002 135,864.40 74,428 90,739 65,505 17.28 3,791 2003 74,562.63 39,288 47,898 37,849 17.88 2,117 2004 117,154.08 59,198 72,171 62,556 18.50 3,381 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-181 Attachment C J. Spanos, Avista Page 661 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 373.20 STREET LIGHTING AND SIGNAL SYSTEMS - UNDERGROUND CONDUCTOR CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 33-S1 NET SALVAGE PERCENT.. -15 2005 89,487.01 43,222 52,694 50,216 19.14 2,624 2006 145,379.18 66,874 81,529 85,657 19.80 4,326 2007 105,681.72 46,109 56,213 65,321 20.48 3,190 2008 111,741.21 45,988 56,066 72,436 21.19 3,418 2009 100,085.15 38,680 47,156 67,942 21.91 3,101 2010 50,128.19 18,063 22,021 35,626 22.66 1,572 2011 25,750.72 8,579 10,459 19,154 23.44 817 2012 48,513.79 14,810 18,056 37,735 24.24 1,557 2013 126,915.49 35,118 42,814 103,139 25.06 4,116 2014 198,132.17 48,954 59,682 168,170 25.91 6,491 2015 356,462.72 77,141 94,046 315,886 26.79 11,791 2016 126,377.71 23,386 28,511 116,823 27.69 4,219 2017 604,572.41 92,490 112,759 582,499 28.61 20,360 2018 456,185.82 54,686 66,670 457,944 29.56 15,492 2019 342,297.83 29,582 36,065 357,578 30.52 11,716 2020 293,896.45 15,260 18,604 319,377 31.51 10,136 2021 426,470.61 7,430 9,058 481,383 32.50 14,812 5,767,344.92 2,294,594 2,775,261 3,857,186 155,806 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 24.8 2.70 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-182 Attachment C J. Spanos, Avista Page 662 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 373.30 STREET LIGHTING AND SIGNAL SYSTEMS - DECORATIVE AND METAL STANDARDS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 33-S1 NET SALVAGE PERCENT.. -15 1964 59.64 64 69 1965 37,179.91 39,388 42,757 1966 349.87 367 402 1967 28,286.67 29,395 32,530 1968 43,227.21 44,484 49,711 1969 26,065.48 26,551 29,975 1970 16,081.55 16,213 18,494 1971 78,802.34 78,594 90,263 360 4.38 82 1972 78,037.06 76,988 88,419 1,324 4.69 282 1973 39,340.19 38,386 44,085 1,156 5.00 231 1974 139,113.16 134,190 154,114 5,866 5.32 1,103 1975 70,670.52 67,381 77,385 3,886 5.64 689 1976 106,652.45 100,462 115,378 7,272 5.97 1,218 1977 122,847.38 114,261 131,226 10,048 6.31 1,592 1978 73,329.04 67,361 77,362 6,966 6.64 1,049 1979 82,607.24 74,876 85,993 9,005 6.99 1,288 1980 103,796.34 92,816 106,597 12,769 7.34 1,740 1981 113,470.52 100,044 114,898 15,593 7.70 2,025 1982 53,856.77 46,808 53,758 8,177 8.06 1,015 1983 77,347.98 66,228 76,061 12,889 8.43 1,529 1984 36,745.07 30,988 35,589 6,668 8.80 758 1985 32,448.76 26,924 30,921 6,395 9.19 696 1986 15,957.61 13,024 14,958 3,393 9.58 354 1987 18,719.34 15,017 17,247 4,280 9.98 429 1988 48,088.53 37,890 43,516 11,786 10.39 1,134 1989 7,084.66 5,481 6,295 1,852 10.80 171 1990 35,159.04 26,674 30,634 9,799 11.23 873 1991 27,390.97 20,360 23,383 8,117 11.67 696 1992 63,151.06 45,973 52,799 19,825 12.11 1,637 1993 196,541.72 139,929 160,705 65,318 12.57 5,196 1994 188,672.27 131,236 150,721 66,252 13.04 5,081 1995 214,481.33 145,600 167,218 79,436 13.52 5,875 1996 159,430.02 105,506 121,171 62,174 14.01 4,438 1997 185,407.89 119,403 137,131 76,088 14.52 5,240 1998 122,311.08 76,552 87,918 52,740 15.04 3,507 1999 115,215.25 69,943 80,328 52,170 15.58 3,349 2000 181,625.17 106,776 122,629 86,240 16.13 5,347 2001 99,807.57 56,728 65,151 49,628 16.69 2,974 2002 240,435.97 131,714 151,270 125,231 17.28 7,247 2003 141,815.25 74,723 85,817 77,271 17.88 4,322 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-183 Attachment C J. Spanos, Avista Page 663 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 373.30 STREET LIGHTING AND SIGNAL SYSTEMS - DECORATIVE AND METAL STANDARDS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 33-S1 NET SALVAGE PERCENT.. -15 2004 549,217.21 277,519 318,723 312,877 18.50 16,912 2005 543,830.43 262,670 301,669 323,736 19.14 16,914 2006 582,712.21 268,048 307,846 362,273 19.80 18,297 2007 750,281.20 327,347 375,949 486,874 20.48 23,773 2008 651,068.84 267,955 307,739 440,990 21.19 20,811 2009 405,509.78 156,717 179,985 286,351 21.91 13,069 2010 444,974.10 160,337 184,143 327,577 22.66 14,456 2011 354,544.97 118,118 135,655 272,072 23.44 11,607 2012 556,120.57 169,766 194,972 444,567 24.24 18,340 2013 509,282.37 140,919 161,842 423,833 25.06 16,913 2014 507,482.27 125,387 144,004 439,601 25.91 16,966 2015 804,911.67 174,189 200,051 725,597 26.79 27,085 2016 968,891.77 179,290 205,910 908,316 27.69 32,803 2017 1,219,106.42 186,504 214,195 1,187,777 28.61 41,516 2018 953,501.33 114,302 131,273 965,254 29.56 32,654 2019 1,010,661.66 87,344 100,312 1,061,949 30.52 34,795 2020 1,317,937.22 68,431 78,591 1,437,037 31.51 45,606 2021 1,612,476.67 28,093 32,264 1,822,084 32.50 56,064 17,164,120.57 5,708,234 6,550,001 13,188,737 531,748 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 24.8 3.10 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-184 Attachment C J. Spanos, Avista Page 664 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 373.40 STREET LIGHTING AND SIGNAL SYSTEMS - HIGH PRESSURE SODIUM VAPOR CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 33-S1 NET SALVAGE PERCENT.. -15 1985 12,088.79 10,031 7,996 5,906 9.19 643 1986 33,830.26 27,611 22,008 16,897 9.58 1,764 1987 22,616.74 18,144 14,462 11,547 9.98 1,157 1988 25,976.14 20,467 16,314 13,559 10.39 1,305 1989 16,959.51 13,121 10,459 9,044 10.80 837 1990 42,979.95 32,607 25,991 23,436 11.23 2,087 1991 39,000.55 28,990 23,108 21,743 11.67 1,863 1992 87,779.36 63,902 50,936 50,010 12.11 4,130 1993 144,903.22 103,164 82,231 84,408 12.57 6,715 1994 173,047.06 120,368 95,944 103,060 13.04 7,903 1995 178,404.75 121,109 96,535 108,630 13.52 8,035 1996 186,717.66 123,564 98,492 116,233 14.01 8,296 1997 263,701.08 169,823 135,364 167,892 14.52 11,563 1998 245,726.85 153,795 122,588 159,998 15.04 10,638 1999 253,788.23 154,065 122,804 169,052 15.58 10,851 2000 311,174.64 182,937 145,817 212,034 16.13 13,145 2001 306,769.67 174,361 138,981 213,804 16.69 12,810 2002 356,255.66 195,162 155,562 254,132 17.28 14,707 2003 398,774.78 210,117 167,482 291,109 17.88 16,281 2004 450,287.48 227,530 181,362 336,469 18.50 18,188 2005 459,788.78 222,078 177,016 351,741 19.14 18,377 2006 646,547.88 297,412 237,064 506,466 19.80 25,579 2007 722,905.40 315,403 251,404 579,937 20.48 28,317 2008 655,903.44 269,945 215,170 539,119 21.19 25,442 2009 910,547.87 351,899 280,495 766,635 21.91 34,990 2010 1,304,407.83 470,017 374,646 1,125,423 22.66 49,666 2011 2,605,283.80 867,963 691,844 2,304,232 23.44 98,303 2012 1,157,272.45 353,278 281,594 1,049,269 24.24 43,287 2013 1,617,064.93 447,444 356,653 1,502,972 25.06 59,975 2014 1,214,109.84 299,979 239,110 1,157,116 25.91 44,659 2015 3,709,512.59 802,764 639,875 3,626,064 26.79 135,351 2016 1,939,193.35 358,841 286,029 1,944,043 27.69 70,207 2017 1,640,204.96 250,926 200,011 1,686,225 28.61 58,938 2018 1,786,877.26 214,204 170,740 1,884,169 29.56 63,740 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-185 Attachment C J. Spanos, Avista Page 665 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 373.40 STREET LIGHTING AND SIGNAL SYSTEMS - HIGH PRESSURE SODIUM VAPOR CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 33-S1 NET SALVAGE PERCENT.. -15 2019 1,666,685.20 144,039 114,812 1,801,876 30.52 59,039 2020 1,665,498.48 86,477 68,930 1,846,393 31.51 58,597 2021 2,271,593.49 39,577 31,546 2,580,787 32.50 79,409 29,524,179.93 7,943,114 6,331,375 27,621,432 1,106,794 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 25.0 3.75 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-186 Attachment C J. Spanos, Avista Page 666 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 373.50 STREET LIGHTING AND SIGNAL SYSTEMS - LED CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 33-S1 NET SALVAGE PERCENT.. -15 2012 814.41 249 354 583 24.24 24 2013 4,324.28 1,197 1,701 3,272 25.06 131 2015 4,316,546.89 934,131 1,327,356 3,636,673 26.79 135,747 2016 3,951,749.61 731,257 1,039,081 3,505,431 27.69 126,596 2017 3,511,601.77 537,221 763,366 3,274,976 28.61 114,470 2018 2,121,260.88 254,288 361,331 2,078,119 29.56 70,302 2019 1,398,142.98 120,831 171,695 1,436,169 30.52 47,057 2020 1,247,720.85 64,785 92,056 1,342,823 31.51 42,616 2021 1,418,531.42 24,714 35,118 1,596,193 32.50 49,114 17,970,693.09 2,668,673 3,792,058 16,874,239 586,057 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 28.8 3.26 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-187 Attachment C J. Spanos, Avista Page 667 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 50-S1 NET SALVAGE PERCENT.. -5 1933 655.76 646 689 1941 35.34 33 36 1 5.43 1949 129.89 115 126 10 7.89 1 1961 8,583.57 6,855 7,507 1,506 11.97 126 1964 282.82 219 240 57 13.08 4 1970 170,154.78 123,527 135,273 43,390 15.43 2,812 1971 25,419.42 18,235 19,969 6,721 15.84 424 1972 14,012.98 9,929 10,873 3,841 16.26 236 1973 3,992.47 2,793 3,059 1,133 16.69 68 1974 266,719.80 184,221 201,738 78,318 17.11 4,577 1975 16,498.26 11,243 12,312 5,011 17.55 286 1976 2,266.22 1,523 1,668 712 17.99 40 1978 84,573.75 55,235 60,487 28,315 18.90 1,498 1979 28,471.42 18,320 20,062 9,833 19.36 508 1980 10,135.84 6,420 7,030 3,613 19.84 182 1981 84,507.70 52,672 57,680 31,053 20.32 1,528 1983 66,741.28 40,225 44,050 26,028 21.30 1,222 1984 1,186.05 702 769 476 21.81 22 1985 44,180.12 25,681 28,123 18,266 22.32 818 1986 62,486.97 35,627 39,015 26,596 22.85 1,164 1987 87,679.78 49,015 53,676 38,388 23.38 1,642 1989 1,191.21 638 699 552 24.48 23 1990 43,297.25 22,695 24,853 20,609 25.04 823 1992 41,222.24 20,594 22,552 20,731 26.21 791 1993 1,895.00 923 1,011 979 26.81 37 1994 95,107.97 45,098 49,386 50,477 27.42 1,841 1995 12,987.81 5,989 6,558 7,079 28.04 252 1996 12,267.88 5,493 6,015 6,866 28.68 239 1997 5,881.01 2,553 2,796 3,379 29.33 115 1998 173,811.50 73,037 79,982 102,520 29.99 3,418 1999 88,605.56 35,968 39,388 53,648 30.67 1,749 2000 18,251.75 7,144 7,823 11,341 31.36 362 2001 1,847.26 696 762 1,178 32.07 37 2004 3,678.04 1,214 1,329 2,533 34.28 74 2005 60,713.46 19,061 20,873 42,876 35.05 1,223 2006 80,503.56 23,955 26,233 58,296 35.83 1,627 2007 39,886.61 11,191 12,255 29,626 36.64 809 2008 30,443.89 8,023 8,786 23,180 37.45 619 2009 1,224,801.10 301,191 329,831 956,210 38.29 24,973 2010 195,686.86 44,628 48,872 156,599 39.14 4,001 2011 2,129,961.07 446,845 489,334 1,747,125 40.01 43,667 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-188 Attachment C J. Spanos, Avista Page 668 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 50-S1 NET SALVAGE PERCENT.. -5 2012 151,925.57 29,033 31,794 127,728 40.90 3,123 2013 664,247.68 114,383 125,259 572,201 41.80 13,689 2014 180,592.76 27,647 30,276 159,346 42.71 3,731 2015 244,567.53 32,613 35,714 221,082 43.65 5,065 2016 1,057,194.29 120,108 131,529 978,525 44.59 21,945 2017 189,113.12 17,633 19,310 179,259 45.56 3,935 2018 200,113.89 14,582 15,968 194,152 46.53 4,173 2019 264,579.64 13,835 15,151 262,658 47.51 5,528 2020 51,839.24 1,633 1,788 52,643 48.50 1,085 2021 9,626,855.79 101,082 110,693 9,997,505 49.50 201,970 17,871,784.76 2,192,721 2,401,202 16,364,172 368,082 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 44.5 2.06 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-189 Attachment C J. Spanos, Avista Page 669 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 391.00 OFFICE FURNITURE AND EQUIPMENT - FURNITURE AND EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 ORIGINAL CALCULATED ALLOC. BOOK FUTURE BOOK REM. ANNUAL YEAR COST ACCRUED RESERVE ACCRUALS LIFE ACCRUAL (1) (2)(3)(4)(5) (6) (7) SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2019 7,797.58 1,300 1,300 6,498 12.50 520 2021 25,241.08 841 841 24,400 14.50 1,683 33,038.66 2,141 2,141 30,898 2,203 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 14.0 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-19 Attachment C J. Spanos, Avista Page 670 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 391.10 OFFICE FURNITURE AND EQUIPMENT - COMPUTER HARDWARE CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-191 Attachment C J. Spanos, Avista Page 671 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 391.12 OFFICE FURNITURE AND EQUIPMENT - COMPUTER HARDWARE - AMI CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 5-SQUARE NET SALVAGE PERCENT.. 0 2019 326,249.47 163,125 163,115 163,134 2.50 65,254 326,249.47 163,125 163,115 163,134 65,254 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 2.5 20.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-192 Attachment C J. Spanos, Avista Page 672 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 392.20 TRANSPORTATION EQUIPMENT - LIGHT TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 14-L2.5 NET SALVAGE PERCENT.. +10 1992 10,541.17 8,274 9,487 1996 87.00 65 78 2001 77,095.33 52,535 69,386 2003 4,099.83 2,667 3,690 2005 5,296.48 3,289 4,689 78 4.34 18 2006 57,522.96 34,945 49,817 1,954 4.55 429 2008 320,880.26 187,302 267,016 21,776 4.92 4,426 2009 71,710.34 40,890 58,292 6,247 5.13 1,218 2010 387,423.18 214,686 306,055 42,626 5.38 7,923 2011 265,493.90 141,489 201,706 37,239 5.71 6,522 2012 437,952.50 221,292 315,472 78,685 6.14 12,815 2013 1,305,363.22 615,104 876,887 297,940 6.67 44,669 2014 880,361.08 378,620 539,757 252,568 7.31 34,551 2015 531,625.96 204,031 290,865 187,598 8.03 23,362 2016 1,482,813.26 492,829 702,573 631,959 8.83 71,570 2017 575,906.81 159,569 227,480 290,836 9.69 30,014 2018 191,377.98 41,830 59,633 112,607 10.60 10,623 2019 443,728.08 70,171 100,035 299,320 11.54 25,938 2020 874,155.17 83,733 119,369 667,371 12.51 53,347 2021 146,274.18 4,701 6,702 124,945 13.50 9,255 8,069,708.69 2,958,022 4,208,989 3,053,749 336,680 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 9.1 4.17 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-193 Attachment C J. Spanos, Avista Page 673 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 392.30 TRANSPORTATION EQUIPMENT - MEDIUM TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 17-L2.5 NET SALVAGE PERCENT.. +10 2000 8,537.74 5,451 7,684 2001 1,546.90 969 1,392 2002 139,095.85 85,569 125,186 2003 313,258.86 189,391 281,090 843 5.58 151 2004 80,860.35 48,074 71,350 1,424 5.77 247 2006 52,961.66 30,394 45,110 2,555 6.16 415 2007 187,700.56 105,433 156,482 12,449 6.39 1,948 2008 181,607.28 99,222 147,263 16,184 6.68 2,423 2009 344,056.91 181,418 269,257 40,394 7.04 5,738 2010 2,804,590.47 1,413,514 2,097,909 426,222 7.48 56,982 2011 543,194.45 258,815 384,128 104,747 8.00 13,093 2012 610,999.64 271,392 402,794 147,106 8.61 17,085 2013 2,174,576.87 886,458 1,315,663 641,456 9.30 68,974 2014 1,597,320.72 586,881 871,037 566,552 10.06 56,317 2015 3,358,156.58 1,088,043 1,614,851 1,407,490 10.88 129,365 2016 2,519,303.41 701,548 1,041,223 1,226,150 11.74 104,442 2017 1,952,170.51 450,606 668,781 1,088,172 12.64 86,090 2018 2,831,202.56 514,101 763,018 1,785,064 13.57 131,545 2019 2,592,321.68 338,975 503,100 1,829,990 14.53 125,946 2020 1,159,991.79 91,506 135,811 908,182 15.51 58,555 2021 2,514,973.90 66,569 98,801 2,164,676 16.50 131,192 25,968,428.69 7,414,329 11,001,930 12,369,656 990,508 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 12.5 3.81 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-194 Attachment C J. Spanos, Avista Page 674 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 392.40 TRANSPORTATION EQUIPMENT - HEAVY TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 20-R4 NET SALVAGE PERCENT.. +10 2013 5,097,472.12 1,919,963 2,434,712 2,153,013 11.63 185,126 2014 803,925.63 268,069 339,939 383,594 12.59 30,468 2015 737,653.53 214,104 271,506 392,382 13.55 28,958 2016 1,061,044.31 261,176 331,198 623,742 14.53 42,928 2017 1,794,809.13 361,834 458,843 1,156,485 15.52 74,516 2018 1,724,095.34 270,769 343,364 1,208,322 16.51 73,187 2019 723,332.14 81,375 103,192 547,807 17.50 31,303 2020 339,270.35 22,901 29,041 276,302 18.50 14,935 2021 483,209.55 10,872 13,787 421,102 19.50 21,595 12,764,812.10 3,411,063 4,325,582 7,162,749 503,016 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 14.2 3.94 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-195 Attachment C J. Spanos, Avista Page 675 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 392.50 TRANSPORTATION EQUIPMENT - OTHER CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 16-L2 NET SALVAGE PERCENT.. +10 1949 261.37 235 235 1962 6,968.11 6,271 6,271 1963 13,792.85 12,414 12,414 1969 5,085.15 4,577 4,577 1975 652.70 587 587 1978 4,721.10 4,143 4,249 1979 3,914.17 3,397 3,523 1994 3,855.02 2,726 3,359 111 3.43 32 1995 807.87 561 691 36 3.66 10 1996 11,960.05 8,147 10,039 725 3.89 186 1997 9,872.66 6,592 8,123 762 4.13 185 1998 96,310.35 63,005 77,635 9,044 4.37 2,070 2001 8,966.62 5,483 6,756 1,314 5.13 256 2002 3,040.16 1,816 2,238 498 5.38 93 2004 21,604.28 12,310 15,168 4,276 5.87 728 2005 23,787.94 13,233 16,306 5,103 6.11 835 2006 96,351.94 52,301 64,446 22,271 6.35 3,507 2007 243,920.86 129,109 159,089 60,440 6.59 9,171 2008 89,006.02 45,811 56,449 23,656 6.85 3,453 2009 609,780.82 303,900 374,468 174,335 7.14 24,417 2010 235,914.93 113,328 139,644 72,679 7.46 9,742 2011 319,839.69 146,806 180,895 106,961 7.84 13,643 2012 787,961.68 341,733 421,086 288,080 8.29 34,750 2013 571,159.73 231,001 284,641 229,403 8.81 26,039 2014 593,244.09 219,238 270,147 263,773 9.43 27,972 2015 778,010.64 256,452 316,002 384,208 10.14 37,890 2016 730,725.95 208,805 257,291 400,362 10.92 36,663 2017 1,074,122.93 256,178 315,665 651,046 11.76 55,361 2018 543,863.68 102,790 126,659 362,818 12.64 28,704 2019 812,448.27 111,509 137,402 593,801 13.56 43,791 2020 305,171.25 25,576 31,515 243,139 14.51 16,757 2021 283,798.61 7,982 9,835 245,584 15.50 15,844 8,290,921.49 2,698,016 3,317,405 4,144,424 392,099 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 10.6 4.73 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-196 Attachment C J. Spanos, Avista Page 676 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 393.00 STORES EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 25-SQUARE NET SALVAGE PERCENT.. 0 2004 1,000.00 700 700 300 7.50 40 2006 20,365.23 12,626 12,626 7,739 9.50 815 2007 180,227.08 104,532 104,534 75,693 10.50 7,209 2008 77,674.33 41,944 41,945 35,729 11.50 3,107 2009 55,664.99 27,832 27,832 27,833 12.50 2,227 2010 6,918.15 3,182 3,182 3,736 13.50 277 2011 4,951.93 2,080 2,080 2,872 14.50 198 2015 5,177.44 1,346 1,346 3,831 18.50 207 2016 35,486.67 7,807 7,807 27,680 19.50 1,419 2021 85,317.54 1,706 1,706 83,611 24.50 3,413 472,783.36 203,755 203,758 269,025 18,912 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 14.2 4.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-197 Attachment C J. Spanos, Avista Page 677 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 394.00 TOOLS, SHOP AND GARAGE EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 20-SQUARE NET SALVAGE PERCENT.. 0 2002 17,431.56 16,996 16,986 446 0.50 446 2003 113,615.96 105,095 105,035 8,581 1.50 5,721 2004 69,562.35 60,867 60,833 8,729 2.50 3,492 2005 172,185.82 142,053 141,973 30,213 3.50 8,632 2006 363,914.03 282,033 281,873 82,041 4.50 18,231 2007 343,127.81 248,768 248,627 94,501 5.50 17,182 2008 106,854.20 72,127 72,086 34,768 6.50 5,349 2009 101,946.64 63,717 63,681 38,266 7.50 5,102 2010 38,716.37 22,262 22,249 16,467 8.50 1,937 2011 121,620.41 63,851 63,815 57,805 9.50 6,085 2012 333,150.73 158,247 158,157 174,994 10.50 16,666 2013 10,976.58 4,665 4,662 6,315 11.50 549 2014 186,059.91 69,772 69,733 116,327 12.50 9,306 2015 857,732.96 278,763 278,605 579,128 13.50 42,898 2016 102,258.31 28,121 28,105 74,153 14.50 5,114 2017 165,800.42 37,305 37,284 128,516 15.50 8,291 2018 1,311,126.59 229,447 229,317 1,081,810 16.50 65,564 2019 1,318,262.84 164,783 164,690 1,153,573 17.50 65,918 2020 896,881.54 67,266 67,228 829,654 18.50 44,846 2021 765,050.86 19,126 19,115 745,936 19.50 38,253 7,396,275.89 2,135,264 2,134,054 5,262,222 369,582 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 14.2 5.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-198 Attachment C J. Spanos, Avista Page 678 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 394.10 TOOLS, SHOP AND GARAGE EQUIPMENT - ELECTRIC VEHICLE CHARGER CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 10-S2.5 NET SALVAGE PERCENT.. 0 2015 51,258.01 30,345 31,759 19,499 4.08 4,779 2017 62,583.22 27,224 28,492 34,091 5.65 6,034 2019 3,388.86 844 883 2,506 7.51 334 117,230.09 58,413 61,134 56,096 11,147 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 5.0 9.51 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-199 Attachment C J. Spanos, Avista Page 679 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 395.00 LABORATORY EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2007 35,970.89 34,772 34,385 1,586 0.50 1,586 2008 14,532.23 13,079 12,933 1,599 1.50 1,066 2009 78,185.98 65,155 64,430 13,756 2.50 5,502 2010 29,068.35 22,286 22,038 7,030 3.50 2,009 2014 101,438.94 50,719 50,155 51,284 7.50 6,838 2017 143,351.76 43,006 42,527 100,825 10.50 9,602 2018 375,480.14 87,611 86,636 288,844 11.50 25,117 2019 681,771.38 113,631 112,366 569,405 12.50 45,552 2020 197,276.95 19,728 19,509 177,768 13.50 13,168 2021 1,244,423.58 41,477 41,015 1,203,408 14.50 82,994 2,901,500.20 491,464 485,994 2,415,506 193,434 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 12.5 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-200 Attachment C J. Spanos, Avista Page 680 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 395.12 LABORATORY EQUIPMENT - AMI CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2018 250,827.91 58,526 58,418 192,410 11.50 16,731 2021 3,055.54 102 101 2,954 14.50 204 253,883.45 58,628 58,519 195,364 16,935 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 11.5 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-201 Attachment C J. Spanos, Avista Page 681 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 396.30 POWER OPERATED EQUIPMENT - MEDIUM TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 16-L2 NET SALVAGE PERCENT.. 0 1983 16,727.50 15,410 16,728 1985 21,906.06 19,688 21,906 1986 89,867.15 79,757 89,867 1987 2,104.00 1,842 2,104 1991 1,765.16 1,457 1,765 1992 113,349.04 92,166 113,349 1993 73,072.19 58,412 72,736 336 3.21 105 1994 207,699.32 163,173 203,187 4,512 3.43 1,315 1995 50,753.96 39,144 48,743 2,011 3.66 549 1996 41,595.96 31,483 39,203 2,393 3.89 615 1997 331,489.46 245,925 306,232 25,257 4.13 6,115 1999 114,069.10 81,132 101,028 13,041 4.62 2,823 2000 25,359.90 17,641 21,967 3,393 4.87 697 2005 101,167.86 62,534 77,869 23,299 6.11 3,813 2007 234,484.94 137,905 171,723 62,762 6.59 9,524 2009 863,738.27 478,295 595,586 268,152 7.14 37,556 2010 930,586.57 496,701 618,505 312,082 7.46 41,834 2011 95,020.67 48,461 60,345 34,676 7.84 4,423 2012 1,015,146.10 489,179 609,139 406,007 8.29 48,976 4,329,903.21 2,560,305 3,171,982 1,157,921 158,345 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 7.3 3.66 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-202 Attachment C J. Spanos, Avista Page 682 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 396.40 POWER OPERATED EQUIPMENT - HEAVY TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 24-S1 NET SALVAGE PERCENT.. 0 1977 84,471.67 81,163 84,472 1979 1,146.08 1,075 1,146 1981 7,579.03 6,929 7,579 1982 69,493.09 62,688 69,493 1984 167,281.33 146,719 167,281 1985 278,254.23 240,573 278,254 1986 327,971.47 279,186 327,971 1987 296,664.85 248,703 296,665 1988 153,169.88 126,301 153,170 1989 100,742.97 81,685 100,743 1992 43,283.01 33,220 43,283 1993 275,773.43 207,520 275,773 1995 512,220.88 369,224 512,221 1996 819,681.21 577,531 819,681 1997 199,198.92 136,949 199,199 1998 35,621.76 23,867 35,622 1999 687,432.55 448,261 687,433 2000 78,631.82 49,833 78,632 2003 768,654.95 441,654 702,164 66,491 10.21 6,512 2004 211,215.90 116,872 185,809 25,407 10.72 2,370 2005 192,766.92 102,407 162,812 29,955 11.25 2,663 2006 755,350.90 383,658 609,959 145,392 11.81 12,311 2007 237,179.47 114,835 182,570 54,609 12.38 4,411 2008 1,947,115.07 894,057 1,421,417 525,698 12.98 40,501 2009 2,194,524.08 950,953 1,511,873 682,651 13.60 50,195 2010 9,081,630.87 3,689,413 5,865,614 3,216,017 14.25 225,685 2012 2,342,263.72 815,881 1,297,128 1,045,135 15.64 66,824 21,869,320.06 10,631,157 16,077,964 5,791,356 411,472 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 14.1 1.88 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-203 Attachment C J. Spanos, Avista Page 683 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 396.50 POWER OPERATED EQUIPMENT - OTHER CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 16-S0 NET SALVAGE PERCENT.. 0 2005 112,824.21 69,528 95,831 16,993 6.14 2,768 2006 35,595.45 20,934 28,853 6,742 6.59 1,023 2007 38,007.61 21,284 29,336 8,672 7.04 1,232 2008 274,599.64 145,708 200,830 73,770 7.51 9,823 2009 84,268.93 42,187 58,147 26,122 7.99 3,269 2010 729,458.94 342,846 472,546 256,913 8.48 30,296 2011 464,930.96 203,696 280,755 184,176 8.99 20,487 2012 214,433.36 86,978 119,882 94,551 9.51 9,942 2013 145,044.60 53,939 74,344 70,701 10.05 7,035 2014 167,960.67 56,583 77,989 89,972 10.61 8,480 2015 90,557.77 27,167 37,444 53,114 11.20 4,742 2016 230,457.18 60,352 83,184 147,273 11.81 12,470 2017 364,425.77 80,629 111,132 253,294 12.46 20,329 2018 564,305.77 100,870 139,030 425,276 13.14 32,365 2019 403,278.71 53,684 73,993 329,286 13.87 23,741 2020 81,132.12 6,795 9,365 71,767 14.66 4,895 2021 55,985.42 1,680 2,316 53,670 15.52 3,458 4,057,267.11 1,374,860 1,894,977 2,162,290 196,355 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 11.0 4.84 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-204 Attachment C J. Spanos, Avista Page 684 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 397.00 COMMUNICATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2007 3,643,256.73 3,521,827 3,476,006 167,251 0.50 167,251 2008 4,104,208.29 3,693,787 3,645,729 458,479 1.50 305,653 2009 2,487,122.24 2,072,594 2,045,628 441,494 2.50 176,598 2010 2,496,255.90 1,913,805 1,888,905 607,351 3.50 173,529 2011 2,896,296.92 2,027,408 2,001,030 895,267 4.50 198,948 2012 4,614,813.01 2,922,700 2,884,674 1,730,139 5.50 314,571 2013 4,501,347.26 2,550,778 2,517,591 1,983,756 6.50 305,193 2014 4,712,884.31 2,356,442 2,325,783 2,387,101 7.50 318,280 2015 3,061,410.29 1,326,601 1,309,341 1,752,069 8.50 206,126 2016 2,511,899.45 921,038 909,055 1,602,844 9.50 168,720 2017 2,003,809.63 601,143 593,322 1,410,488 10.50 134,332 2018 1,878,781.70 438,376 432,672 1,446,110 11.50 125,749 2019 1,745,675.86 290,952 287,167 1,458,509 12.50 116,681 2020 3,768,842.58 376,884 371,981 3,396,862 13.50 251,619 2021 1,676,492.76 55,878 55,151 1,621,342 14.50 111,817 46,103,096.93 25,070,213 24,744,035 21,359,062 3,075,067 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 6.9 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-205 Attachment C J. Spanos, Avista Page 685 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 397.50 COMMUNICATION EQUIPMENT - SUB INTEGRATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2014 164,776.10 82,388 82,313 82,463 7.50 10,995 2015 131,124.18 56,820 56,768 74,356 8.50 8,748 2016 599,508.16 219,822 219,621 379,887 9.50 39,988 2017 142,898.78 42,870 42,831 100,068 10.50 9,530 2018 305,455.26 71,272 71,206 234,249 11.50 20,369 2019 652,787.50 108,800 108,700 544,088 12.50 43,527 2020 348,623.75 34,862 34,830 313,794 13.50 23,244 2021 1,192,651.64 39,751 39,715 1,152,937 14.50 79,513 3,537,825.37 656,585 655,984 2,881,841 235,914 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 12.2 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-206 Attachment C J. Spanos, Avista Page 686 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 397.60 COMMUNICATION EQUIPMENT - DISTRIBUTION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2020 342,491.50 34,249 34,049 308,442 13.50 22,848 2021 221,472.98 7,382 7,338 214,135 14.50 14,768 563,964.48 41,631 41,387 522,577 37,616 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 13.9 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-207 Attachment C J. Spanos, Avista Page 687 of 800 AVISTA CORPORATION ELECTRIC PLANT ACCOUNT 398.00 MISCELLANEOUS EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 10-SQUARE NET SALVAGE PERCENT.. 0 2012 17,352.88 16,485 16,286 1,067 0.50 1,067 2013 63,764.84 54,200 53,544 10,221 1.50 6,814 2014 43,349.30 32,512 32,119 11,230 2.50 4,492 2016 12,672.06 6,970 6,886 5,786 4.50 1,286 2017 1,703.32 766 757 946 5.50 172 2018 2,322.60 813 803 1,520 6.50 234 2019 47,643.32 11,911 11,767 35,876 7.50 4,783 2020 85,132.90 12,770 12,615 72,518 8.50 8,532 2021 14,607.35 730 721 13,886 9.50 1,462 288,548.57 137,157 135,498 153,051 28,842 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 5.3 10.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-208 Attachment C J. Spanos, Avista Page 688 of 800 GAS PLANT _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-209 Attachment C J. Spanos, Avista Page 689 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 350.20 RIGHTS OF WAY CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-R4 NET SALVAGE PERCENT.. 0 1970 16,214.00 11,784 14,360 1,854 17.76 104 1973 2,826.70 1,960 2,388 439 19.94 22 1996 4,833.33 1,872 2,281 2,552 39.83 64 2006 35,937.69 8,531 10,397 25,541 49.57 515 2012 6,261.32 913 1,112 5,149 55.52 93 66,073.04 25,060 30,538 35,535 798 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 44.5 1.21 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-210 Attachment C J. Spanos, Avista Page 690 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 351.10 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 55-R2.5 NET SALVAGE PERCENT.. -5 1970 34,510.16 26,452 34,459 1,777 14.85 120 1971 1,295.98 981 1,278 83 15.37 5 1975 92,314.08 65,912 85,864 11,066 17.60 629 1976 35,047.63 24,623 32,076 4,724 18.20 260 1978 25,117.20 17,061 22,225 4,148 19.42 214 1979 3,729.91 2,488 3,241 675 20.06 34 1980 21,392.92 14,009 18,250 4,213 20.70 204 1981 68,832.91 44,206 57,587 14,688 21.36 688 1983 22,432.63 13,828 18,014 5,540 22.71 244 1984 14,437.73 8,710 11,347 3,813 23.40 163 1987 14,779.91 8,315 10,832 4,687 25.53 184 1989 227,947.75 121,848 158,731 80,614 27.00 2,986 1990 77.75 40 52 30 27.75 1 1991 60.33 31 40 23 28.50 1 1992 8,151.94 4,004 5,216 3,344 29.27 114 1993 27,627.49 13,160 17,144 11,865 30.05 395 2003 1,932.64 619 806 1,223 38.23 32 2007 26,075.94 6,616 8,619 18,761 41.71 450 2008 361.59 86 112 268 42.59 6 2009 162,937.49 35,834 46,681 124,403 43.48 2,861 2010 4,703.15 954 1,243 3,695 44.38 83 2011 47,556.32 8,825 11,496 38,438 45.28 849 2012 238,300.33 40,125 52,270 197,945 46.18 4,286 2019 4,361.30 196 255 4,324 52.65 82 2020 426,205.74 11,555 15,053 432,463 53.58 8,071 2021 424,481.23 3,811 4,965 440,740 54.53 8,083 1,934,672.05 474,289 617,856 1,413,550 31,045 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 45.5 1.60 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-211 Attachment C J. Spanos, Avista Page 691 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 351.20 STRUCTURES AND IMPROVEMENTS - COMPRESSOR STATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 55-R2.5 NET SALVAGE PERCENT.. -5 1970 16,134.34 12,367 15,531 1,410 14.85 95 1971 605.79 458 575 61 15.37 4 1975 43,151.40 30,810 38,692 6,617 17.60 376 1976 16,382.70 11,510 14,455 2,747 18.20 151 1978 11,740.81 7,975 10,015 2,313 19.42 119 1979 1,743.51 1,163 1,461 370 20.06 18 1980 9,999.93 6,548 8,223 2,277 20.70 110 1981 32,175.33 20,664 25,951 7,833 21.36 367 1983 10,485.93 6,464 8,118 2,892 22.71 127 1984 6,748.79 4,071 5,112 1,974 23.40 84 1987 6,908.74 3,887 4,881 2,373 25.53 93 1989 106,552.15 56,957 71,529 40,351 27.00 1,494 1990 36.34 19 24 14 27.75 1 1991 28.20 14 18 12 28.50 1992 3,810.55 1,872 2,351 1,650 29.27 56 1993 5,619.41 2,677 3,361 2,539 30.05 84 2008 3,130.61 742 932 2,356 42.59 55 275,254.53 168,198 211,229 77,789 3,234 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 24.1 1.17 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-212 Attachment C J. Spanos, Avista Page 692 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 351.30 STRUCTURES AND IMPROVEMENTS - MEASURING AND REGULATING STATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 55-R2.5 NET SALVAGE PERCENT.. -5 1970 3,046.54 2,335 2,990 209 14.85 14 1971 114.59 87 111 9 15.37 1 1975 8,162.63 5,828 7,462 1,109 17.60 63 1976 3,098.99 2,177 2,787 467 18.20 26 1978 2,220.92 1,509 1,932 400 19.42 21 1979 329.81 220 282 64 20.06 3 1980 1,891.61 1,239 1,586 400 20.70 19 1981 6,086.37 3,909 5,005 1,386 21.36 65 1983 1,983.55 1,223 1,566 517 22.71 23 1984 1,276.62 770 986 354 23.40 15 1987 1,306.87 735 941 431 25.53 17 1989 20,155.67 10,774 13,796 7,367 27.00 273 1990 6.87 4 5 2 27.75 1991 5.33 3 4 2 28.50 1992 720.81 354 453 304 29.27 10 1993 2,442.89 1,164 1,490 1,075 30.05 36 52,850.07 32,331 41,396 14,096 586 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 24.1 1.11 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-213 Attachment C J. Spanos, Avista Page 693 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 351.40 STRUCTURES AND IMPROVEMENTS - OFFICE CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 55-R2.5 NET SALVAGE PERCENT.. -5 1970 7,603.33 5,828 7,291 692 14.85 47 1971 285.64 216 270 30 15.37 2 1975 20,345.89 14,527 18,173 3,190 17.60 181 1976 7,724.45 5,427 6,789 1,322 18.20 73 1978 5,535.80 3,760 4,704 1,109 19.42 57 1979 822.07 548 686 177 20.06 9 1980 4,714.97 3,087 3,862 1,089 20.70 53 1981 15,170.68 9,743 12,188 3,741 21.36 175 1983 4,944.12 3,048 3,813 1,378 22.71 61 1984 3,182.06 1,920 2,402 939 23.40 40 1987 3,257.47 1,833 2,293 1,127 25.53 44 1989 50,239.36 26,855 33,594 19,157 27.00 710 1990 17.14 9 11 7 27.75 1991 13.29 7 9 5 28.50 1992 1,796.67 883 1,105 782 29.27 27 1993 6,089.06 2,900 3,628 2,766 30.05 92 2006 12,060.67 3,263 4,082 8,582 40.83 210 2007 22,793.56 5,783 7,234 16,699 41.71 400 2009 500.14 110 138 387 43.48 9 2010 4,795.70 972 1,215 3,820 44.38 86 171,892.07 90,719 113,487 67,000 2,276 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 29.4 1.32 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-214 Attachment C J. Spanos, Avista Page 694 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 352.00 WELLS - STORAGE WELLS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 60-R4 NET SALVAGE PERCENT.. 0 1970 2,367,697.47 1,828,265 2,070,399 297,298 13.67 21,748 1971 32,450.00 24,694 27,964 4,486 14.34 313 1972 231,671.00 173,677 196,679 34,992 15.02 2,330 1973 44,247.66 32,655 36,980 7,268 15.72 462 1974 235,396.47 170,976 193,620 41,776 16.42 2,544 1975 496,444.41 354,625 401,591 94,853 17.14 5,534 1976 330,901.29 232,349 263,121 67,780 17.87 3,793 1977 42,162.26 29,085 32,937 9,225 18.61 496 1978 52,844.42 35,785 40,524 12,320 19.37 636 1979 14,762.11 9,809 11,108 3,654 20.13 182 1981 997.10 636 720 277 21.71 13 1982 26,136.28 16,331 18,494 7,642 22.51 339 1984 8,425.85 5,033 5,700 2,726 24.16 113 1989 2,370.20 1,246 1,411 959 28.47 34 1991 1,362.36 675 764 598 30.27 20 1992 8,439.84 4,054 4,591 3,849 31.18 123 1993 79,856.83 37,133 42,051 37,806 32.10 1,178 1994 73,750.73 33,151 37,542 36,209 33.03 1,096 1995 635,871.46 275,968 312,517 323,354 33.96 9,522 1996 475,767.26 199,028 225,387 250,380 34.90 7,174 1997 307,277.42 123,679 140,059 167,218 35.85 4,664 1998 50,694.31 19,602 22,198 28,496 36.80 774 2000 1,130.00 401 454 676 38.72 17 2001 14,870.55 5,034 5,701 9,170 39.69 231 2003 186,120.82 56,953 64,496 121,625 41.64 2,921 2004 947.48 274 310 637 42.62 15 2005 65,256.88 17,837 20,199 45,058 43.60 1,033 2006 79,258.72 20,369 23,067 56,192 44.58 1,260 2007 29,593.35 7,117 8,060 21,533 45.57 473 2008 2,171,182.16 486,345 550,756 1,620,426 46.56 34,803 2009 25,006.16 5,189 5,876 19,130 47.55 402 2010 51,049.85 9,751 11,042 40,008 48.54 824 2011 4,086,507.57 713,096 807,538 3,278,970 49.53 66,202 2012 4,428,663.89 699,729 792,401 3,636,263 50.52 71,977 2019 4,361.43 182 206 4,155 57.50 72 2020 426,218.37 10,655 12,066 414,152 58.50 7,080 2021 424,493.83 3,536 4,005 420,489 59.50 7,067 17,514,187.79 5,644,924 6,392,534 11,121,654 257,465 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 43.2 1.47 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-215 Attachment C J. Spanos, Avista Page 695 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 352.20 WELLS - RESERVOIRS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 50-R4 NET SALVAGE PERCENT.. 0 1988 36,848.32 23,369 24,649 12,199 18.29 667 1993 7,388.06 4,066 4,289 3,099 22.48 138 1994 12,132.80 6,464 6,818 5,315 23.36 228 1997 16,402.53 7,854 8,284 8,119 26.06 312 2000 74,373.33 31,460 33,184 41,189 28.85 1,428 2002 56,185.43 21,631 22,816 33,369 30.75 1,085 203,330.47 94,844 100,040 103,290 3,858 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 26.8 1.90 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-216 Attachment C J. Spanos, Avista Page 696 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 352.30 WELLS - NON-RECOVERABLE GAS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 50-R4 NET SALVAGE PERCENT.. 0 1975 278,861.11 227,885 278,861 1976 605,089.71 487,218 605,090 1977 449,025.91 355,988 449,026 1978 520,874.89 406,282 514,288 6,587 11.00 599 1979 636,016.95 487,571 617,187 18,830 11.67 1,614 1980 184,746.69 139,114 176,096 8,651 12.35 700 1981 271,906.27 200,993 254,425 17,481 13.04 1,341 1996 116,975.90 58,137 73,592 43,384 25.15 1,725 1999 966,182.28 426,859 540,335 425,847 27.91 15,258 2000 71,481.76 30,237 38,275 33,207 28.85 1,151 2011 1,258,528.94 263,284 333,275 925,254 39.54 23,400 5,359,690.41 3,083,568 3,880,450 1,479,240 45,788 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 32.3 0.85 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-217 Attachment C J. Spanos, Avista Page 697 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 353.00 LINES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-R4 NET SALVAGE PERCENT.. 0 1970 217,119.00 157,796 163,515 53,604 17.76 3,018 1971 16,165.00 11,569 11,988 4,177 18.48 226 1972 21,340.00 15,037 15,582 5,758 19.20 300 1973 200.95 139 144 57 19.94 3 1975 24,512.39 16,420 17,015 7,497 21.46 349 1976 2,821.06 1,856 1,923 898 22.23 40 1989 271,252.69 132,371 137,169 134,084 33.28 4,029 1990 20,277.94 9,609 9,957 10,321 34.20 302 1991 19,152.46 8,804 9,123 10,029 35.12 286 1992 3,012.67 1,342 1,391 1,622 36.05 45 1994 15,313.43 6,377 6,608 8,705 37.93 230 1995 115,904.24 46,576 48,264 67,640 38.88 1,740 1996 65,311.81 25,291 26,208 39,104 39.83 982 1997 1,885.76 702 727 1,159 40.79 28 2002 24,410.19 7,271 7,535 16,875 45.64 370 2007 865.56 192 199 667 50.56 13 2008 185,729.23 38,431 39,824 145,905 51.55 2,830 2009 35,511.13 6,807 7,054 28,457 52.54 542 2010 3,691.61 651 675 3,017 53.53 56 2012 1,015,299.65 148,081 153,448 861,852 55.52 15,523 2,059,776.77 635,322 658,349 1,401,428 30,912 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 45.3 1.50 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-218 Attachment C J. Spanos, Avista Page 698 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 354.00 COMPRESSOR STATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 55-R4 NET SALVAGE PERCENT.. 0 1970 515,212.89 422,851 441,554 73,659 9.86 7,470 1971 1,752.46 1,420 1,483 269 10.44 26 1972 10,745.50 8,587 8,967 1,778 11.05 161 1973 3,132.45 2,467 2,576 556 11.68 48 1974 207,282.60 160,777 167,888 39,395 12.34 3,192 1975 151,427.04 115,636 120,751 30,676 13.00 2,360 1976 13,385.21 10,056 10,501 2,884 13.68 211 1980 2,662.02 1,862 1,944 718 16.53 43 1984 5,157.19 3,319 3,466 1,691 19.60 86 1989 132,698.73 75,446 78,783 53,916 23.73 2,272 1990 23,126.06 12,782 13,347 9,779 24.60 398 1991 73,559.20 39,495 41,242 32,317 25.47 1,269 1993 9,884.54 4,987 5,208 4,677 27.25 172 1995 6,764.75 3,188 3,329 3,436 29.08 118 1996 153,399.68 69,728 72,812 80,588 30.00 2,686 1997 720.48 315 329 391 30.93 13 1998 20,258.69 8,520 8,897 11,362 31.87 357 1999 3,251.87 1,311 1,369 1,883 32.82 57 2000 66,466.13 25,656 26,791 39,675 33.77 1,175 2001 323,674.42 119,290 124,566 199,108 34.73 5,733 2002 362.35 127 133 229 35.70 6 2003 40,916.10 13,636 14,239 26,677 36.67 727 2004 82,829.87 26,144 27,300 55,530 37.64 1,475 2005 7,864.43 2,342 2,446 5,418 38.62 140 2008 9,197,250.55 2,247,440 2,346,843 6,850,408 41.56 164,832 2009 793.47 180 188 605 42.55 14 2010 20,310.31 4,232 4,419 15,891 43.54 365 2011 227,104.33 43,232 45,144 181,960 44.53 4,086 2012 2,793,358.62 480,960 502,233 2,291,126 45.53 50,321 2019 4,361.43 198 207 4,154 52.50 79 2020 426,218.37 11,623 12,137 414,081 53.50 7,740 2021 424,493.83 3,859 4,030 420,464 54.50 7,715 14,950,425.57 3,921,666 4,095,122 10,855,304 265,347 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 40.9 1.77 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-219 Attachment C J. Spanos, Avista Page 699 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 355.00 MEASURING AND REGULATING EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 35-R3 NET SALVAGE PERCENT.. 0 1970 4,251.55 4,026 4,252 1972 2,166.00 2,019 2,166 1973 723.28 669 723 1974 1,229.43 1,128 1,229 1975 449.47 409 449 1977 3,791.16 3,393 3,791 1979 7,953.38 6,990 7,953 1980 2,286.77 1,989 2,287 1981 18,569.80 15,986 18,570 1982 7,466.73 6,355 7,467 1983 6,194.07 5,207 6,194 1984 8,469.02 7,024 8,469 1989 183.85 140 184 1992 29,324.97 20,905 29,325 1993 477.97 332 478 1994 3,076.29 2,081 3,076 1995 11,006.56 7,236 11,007 2012 596,587.24 155,626 596,587 2019 4,361.43 305 2,473 1,888 32.55 58 2020 426,218.37 17,901 145,151 281,067 33.53 8,383 2021 424,493.83 5,943 48,189 376,304 34.51 10,904 1,559,281.17 265,664 900,020 659,261 19,345 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 34.1 1.24 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-220 Attachment C J. Spanos, Avista Page 700 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 356.00 PURIFICATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 35-S2.5 NET SALVAGE PERCENT.. 0 1970 78,905.27 71,105 78,905 1971 1,891.00 1,693 1,891 1972 85.00 76 85 1976 88,306.44 76,322 86,123 2,183 4.75 460 1977 1,680.05 1,441 1,626 54 4.99 11 1989 136,934.13 102,113 115,227 21,707 8.90 2,439 1990 3,852.40 2,824 3,187 665 9.34 71 1991 92,058.33 66,255 74,763 17,295 9.81 1,763 2012 141,430.14 38,106 43,000 98,430 25.57 3,849 545,142.76 359,935 404,807 140,336 8,593 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 16.3 1.58 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-221 Attachment C J. Spanos, Avista Page 701 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 357.00 OTHER EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 45-R2 NET SALVAGE PERCENT.. 0 1970 290,812.02 228,578 289,577 1,235 9.63 128 1972 669.71 514 651 19 10.44 2 1973 2,484.59 1,885 2,388 97 10.86 9 1974 1,976.73 1,480 1,875 102 11.30 9 1975 5,065.62 3,743 4,742 324 11.75 28 1976 109.63 80 101 9 12.21 1 1977 1,008.39 724 917 91 12.69 7 1978 5,296.64 3,745 4,744 553 13.18 42 1979 2,598.61 1,809 2,292 307 13.68 22 1980 302.98 207 262 41 14.19 3 1981 2,726.49 1,835 2,325 401 14.72 27 1983 107.28 70 89 18 15.82 1 1984 2,050.37 1,304 1,652 398 16.39 24 1985 1,922.81 1,198 1,518 405 16.97 24 1986 3,690.05 2,250 2,850 840 17.56 48 1987 1,927.51 1,150 1,457 471 18.16 26 1988 15,235.83 8,877 11,246 3,990 18.78 212 1990 16,892.23 9,366 11,865 5,027 20.05 251 1991 4,988.00 2,694 3,413 1,575 20.70 76 1993 7,022.95 3,583 4,539 2,484 22.04 113 1994 2,305.41 1,141 1,445 860 22.73 38 1995 745,253.54 357,394 452,770 292,484 23.42 12,489 1996 160,514.61 74,443 94,309 66,206 24.13 2,744 1998 6,571.75 2,838 3,595 2,977 25.57 116 1999 10,296.61 4,279 5,421 4,876 26.30 185 2005 24,313.85 7,613 9,645 14,669 30.91 475 2006 9,930.69 2,933 3,716 6,215 31.71 196 2007 27,802.05 7,717 9,776 18,026 32.51 554 2008 9,500.01 2,466 3,124 6,376 33.32 191 2009 19,014.89 4,585 5,809 13,206 34.15 387 2010 24,485.59 5,452 6,907 17,579 34.98 503 2011 17,610.10 3,596 4,556 13,054 35.81 365 2012 293,337.89 54,364 68,871 224,467 36.66 6,123 2019 4,361.43 218 276 4,085 42.75 96 2020 426,218.37 12,787 16,199 410,019 43.65 9,393 2021 424,493.83 4,245 5,378 419,116 44.55 9,408 2,572,899.06 821,163 1,040,300 1,532,599 44,316 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 34.6 1.72 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-222 Attachment C J. Spanos, Avista Page 702 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 374.40 LAND - EASEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 60-R4 NET SALVAGE PERCENT.. 0 2006 1,278.94 329 275 1,004 44.58 23 2009 64,232.41 13,328 11,130 53,102 47.55 1,117 2010 6,051.39 1,156 965 5,086 48.54 105 2013 149,308.19 21,102 17,623 131,685 51.52 2,556 2014 4,244.22 530 443 3,801 52.51 72 2015 154,895.34 16,755 13,992 140,903 53.51 2,633 2017 60,983.41 4,563 3,811 57,172 55.51 1,030 2018 29,286.83 1,708 1,426 27,861 56.50 493 2019 149,780.29 6,241 5,212 144,568 57.50 2,514 2021 47,963.17 400 334 47,629 59.50 800 668,024.19 66,112 55,211 612,813 11,343 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 54.0 1.70 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-223 Attachment C J. Spanos, Avista Page 703 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 375.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 45-R2 NET SALVAGE PERCENT.. 0 1958 3,064.36 2,683 2,278 786 5.60 140 1959 524.96 456 387 138 5.90 23 1963 556.29 468 397 159 7.14 22 1966 398.57 326 277 122 8.15 15 1967 589.01 478 406 183 8.50 22 1969 1,263.70 1,004 852 412 9.24 45 1972 12,903.78 9,910 8,413 4,491 10.44 430 1973 14,533.35 11,026 9,361 5,172 10.86 476 1974 1,839.61 1,378 1,170 670 11.30 59 1975 7,131.42 5,269 4,473 2,658 11.75 226 1976 2,937.25 2,140 1,817 1,120 12.21 92 1978 4,905.10 3,468 2,944 1,961 13.18 149 1981 1,653.47 1,113 945 708 14.72 48 1983 2,462.33 1,597 1,356 1,106 15.82 70 1985 23,578.75 14,687 12,469 11,110 16.97 655 1986 3,227.54 1,968 1,671 1,557 17.56 89 1987 2,871.29 1,713 1,454 1,417 18.16 78 1988 3,469.05 2,021 1,716 1,753 18.78 93 1989 18,065.61 10,273 8,721 9,345 19.41 481 1990 4,269.84 2,367 2,010 2,260 20.05 113 1992 953.67 501 425 529 21.37 25 1993 45,047.57 22,984 19,513 25,535 22.04 1,159 1994 12,872.81 6,371 5,409 7,464 22.73 328 1995 2,215.44 1,062 902 1,313 23.42 56 1996 10,295.71 4,775 4,054 6,242 24.13 259 1997 3,805.56 1,705 1,447 2,359 24.84 95 1998 24,005.75 10,365 8,799 15,207 25.57 595 1999 24,392.45 10,137 8,606 15,786 26.30 600 2000 60,528.31 24,144 20,497 40,031 27.05 1,480 2001 17,970.43 6,869 5,832 12,138 27.80 437 2002 25,593.23 9,344 7,933 17,660 28.57 618 2003 2,965.33 1,032 876 2,089 29.34 71 2004 9,603.94 3,176 2,696 6,908 30.12 229 2005 40,717.14 12,749 10,823 29,894 30.91 967 2006 30,339.77 8,960 7,607 22,733 31.71 717 2007 19,988.17 5,548 4,710 15,278 32.51 470 2008 26,640.49 6,915 5,871 20,769 33.32 623 2009 36,184.76 8,725 7,407 28,778 34.15 843 2010 131,073.27 29,186 24,778 106,295 34.98 3,039 2011 74,129.33 15,139 12,852 61,277 35.81 1,711 2012 15,548.86 2,882 2,447 13,102 36.66 357 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-224 Attachment C J. Spanos, Avista Page 704 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 375.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 45-R2 NET SALVAGE PERCENT.. 0 2013 20,080.58 3,342 2,837 17,244 37.51 460 2014 135,923.21 20,057 17,028 118,895 38.36 3,099 2015 162,979.96 20,897 17,741 145,239 39.23 3,702 2016 18,183.34 1,980 1,681 16,502 40.10 412 2017 126,864.20 11,333 9,621 117,243 40.98 2,861 2018 191,834.76 13,386 11,364 180,471 41.86 4,311 2019 52,338.60 2,617 2,222 50,117 42.75 1,172 2020 60,146.81 1,804 1,532 58,615 43.65 1,343 2021 82,120.08 821 697 81,423 44.55 1,828 1,575,588.81 343,151 291,324 1,284,265 37,193 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 34.5 2.36 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-225 Attachment C J. Spanos, Avista Page 705 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 376.00 MAINS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 55-R3 NET SALVAGE PERCENT.. -20 1957 1,786,896.16 1,856,942 1,988,367 155,908 7.37 21,154 1958 824,396.31 850,777 910,991 78,285 7.70 10,167 1959 1,218,421.95 1,248,376 1,336,730 125,376 8.04 15,594 1960 585,158.89 594,945 637,052 65,139 8.40 7,755 1961 478,842.46 482,989 517,173 57,438 8.77 6,549 1962 694,657.82 694,755 743,926 89,663 9.16 9,789 1963 1,001,791.18 993,192 1,063,485 138,664 9.56 14,505 1964 789,790.35 775,779 830,685 117,063 9.98 11,730 1965 1,525,207.45 1,483,838 1,588,857 241,392 10.41 23,188 1966 2,592,393.89 2,496,631 2,673,330 437,543 10.86 40,289 1967 1,492,443.39 1,422,000 1,522,642 268,290 11.33 23,680 1968 2,035,124.97 1,917,308 2,053,005 389,145 11.82 32,923 1969 1,306,016.14 1,215,880 1,301,934 265,285 12.33 21,515 1970 160,143.77 147,273 157,696 34,477 12.85 2,683 1971 1,118,705.35 1,015,628 1,087,509 254,937 13.39 19,039 1972 1,438,161.71 1,288,392 1,379,578 346,216 13.94 24,836 1973 288,819.18 255,147 273,205 73,378 14.51 5,057 1974 640,485.95 557,569 597,031 171,552 15.10 11,361 1975 287,969.40 246,857 264,328 81,235 15.71 5,171 1976 203,474.66 171,717 183,870 60,300 16.32 3,695 1977 243,430.03 202,039 216,338 75,778 16.96 4,468 1978 381,314.71 311,070 333,086 124,492 17.61 7,069 1979 811,925.59 650,664 696,715 277,596 18.27 15,194 1980 766,431.11 603,003 645,681 274,036 18.94 14,469 1981 674,434.84 520,467 557,303 252,019 19.63 12,838 1982 409,820.33 310,001 331,941 159,843 20.33 7,862 1983 463,360.09 343,322 367,621 188,411 21.04 8,955 1984 1,142,801.02 828,549 887,190 484,171 21.77 22,240 1985 1,036,992.68 735,323 787,365 457,026 22.50 20,312 1986 3,273,643.72 2,267,732 2,428,231 1,500,141 23.25 64,522 1987 2,576,838.53 1,742,304 1,865,616 1,226,590 24.01 51,087 1988 655,726.04 432,496 463,106 323,765 24.77 13,071 1989 1,941,731.94 1,247,640 1,335,942 994,136 25.55 38,909 1990 3,867,471.57 2,418,361 2,589,520 2,051,446 26.34 77,883 1991 3,746,609.39 2,277,414 2,438,598 2,057,333 27.14 75,804 1992 6,535,570.90 3,858,601 4,131,693 3,710,992 27.94 132,820 1993 8,029,851.61 4,597,154 4,922,517 4,713,305 28.76 163,884 1994 7,166,661.03 3,973,197 4,254,400 4,345,593 29.59 146,860 1995 8,072,677.51 4,329,312 4,635,719 5,051,494 30.42 166,058 1996 8,261,885.62 4,279,392 4,582,266 5,331,997 31.26 170,569 1997 8,364,433.62 4,177,332 4,472,982 5,564,338 32.11 173,290 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-226 Attachment C J. Spanos, Avista Page 706 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 376.00 MAINS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 55-R3 NET SALVAGE PERCENT.. -20 1998 8,930,829.94 4,292,693 4,596,508 6,120,488 32.97 185,638 1999 7,365,336.74 3,400,399 3,641,062 5,197,342 33.84 153,586 2000 9,579,232.11 4,238,580 4,538,565 6,956,514 34.72 200,360 2001 4,019,471.20 1,701,346 1,821,759 3,001,606 35.60 84,315 2002 3,655,016.82 1,476,115 1,580,587 2,805,433 36.49 76,882 2003 6,186,277.91 2,376,867 2,545,090 4,878,443 37.39 130,475 2004 5,303,423.52 1,932,398 2,069,163 4,294,945 38.30 112,140 2005 6,255,927.45 2,155,217 2,307,752 5,199,361 39.21 132,603 2006 11,169,163.99 3,623,634 3,880,097 9,522,900 40.13 237,301 2007 13,338,984.56 4,056,919 4,344,047 11,662,734 41.06 284,041 2008 16,841,984.92 4,780,766 5,119,125 15,091,257 41.99 359,401 2009 12,145,076.39 3,198,284 3,424,642 11,149,450 42.93 259,712 2010 6,888,381.61 1,672,719 1,791,106 6,474,952 43.87 147,594 2011 10,867,580.82 2,416,124 2,587,125 10,453,972 44.81 233,296 2012 7,105,370.97 1,430,908 1,532,180 6,994,265 45.77 152,813 2013 18,397,659.75 3,323,721 3,558,957 18,518,235 46.72 396,366 2014 14,246,033.65 2,272,128 2,432,938 14,662,302 47.69 307,450 2015 25,345,962.79 3,511,430 3,759,952 26,655,203 48.65 547,897 2016 21,555,703.32 2,530,295 2,709,377 23,157,467 49.62 466,696 2017 30,070,848.00 2,893,297 3,098,070 32,986,948 50.59 652,045 2018 30,775,799.34 2,303,015 2,466,011 34,464,948 51.57 668,314 2019 28,698,334.06 1,540,412 1,649,434 32,788,567 52.54 624,069 2020 24,790,864.15 800,547 857,206 28,891,831 53.52 539,832 2021 24,707,491.28 264,172 282,869 29,366,121 54.51 538,729 437,133,268.15 122,013,354 130,648,846 393,911,076 9,190,399 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 42.9 2.10 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-227 Attachment C J. Spanos, Avista Page 707 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 378.00 MEASURING AND REGULATING EQUIPMENT - GENERAL CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 32-R2 NET SALVAGE PERCENT.. -15 1959 807.10 928 928 1966 472.75 526 434 110 1.02 108 1970 267.03 287 237 70 2.14 33 1972 1,614.47 1,699 1,401 456 2.71 168 1974 898.20 927 765 268 3.29 81 1975 3,904.34 3,986 3,288 1,202 3.59 335 1990 15,143.64 12,468 10,283 7,132 9.09 785 1992 151,712.27 119,403 98,483 75,986 10.10 7,523 1993 87,763.79 67,401 55,592 45,336 10.63 4,265 1994 120,941.89 90,490 74,635 64,448 11.18 5,765 1995 172,779.35 125,737 103,707 94,989 11.75 8,084 1996 171,055.41 120,918 99,732 96,982 12.33 7,866 1997 119,361.47 81,758 67,433 69,833 12.94 5,397 1998 276,173.86 183,017 150,951 166,649 13.56 12,290 1999 419,365.62 268,412 221,384 260,886 14.19 18,385 2000 323,505.07 199,386 164,452 207,579 14.85 13,978 2001 187,425.57 111,070 91,609 123,930 15.51 7,990 2002 271,017.17 153,887 126,925 184,745 16.20 11,404 2003 86,927.76 47,172 38,907 61,060 16.90 3,613 2004 111,064.22 57,436 47,373 80,351 17.61 4,563 2005 158,499.75 77,809 64,176 118,099 18.34 6,439 2006 144,530.14 67,107 55,349 110,861 19.08 5,810 2007 72,117.65 31,541 26,015 56,920 19.83 2,870 2008 500,150.86 204,906 169,004 406,169 20.60 19,717 2009 387,394.10 147,992 122,062 323,441 21.37 15,135 2010 529,500.85 187,245 154,438 454,488 22.16 20,509 2011 256,301.83 83,175 68,602 226,145 22.97 9,845 2012 179,150.28 52,923 43,650 162,373 23.78 6,828 2013 70,896.48 18,854 15,551 65,980 24.60 2,682 2014 242,474.30 57,163 47,148 231,697 25.44 9,108 2015 456,028.48 93,742 77,317 447,116 26.28 17,014 2016 161,317.16 28,176 23,239 162,276 27.14 5,979 2017 335,312.80 48,201 39,756 345,854 28.00 12,352 2018 441,462.37 49,499 40,826 466,856 28.88 16,165 2019 169,083.31 13,611 11,226 183,220 29.76 6,157 2020 101,850.69 4,942 4,076 113,052 30.65 3,688 2021 404,464.20 6,540 5,395 459,739 31.55 14,572 7,132,736.23 2,820,334 2,326,349 5,876,298 287,503 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 20.4 4.03 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-228 Attachment C J. Spanos, Avista Page 708 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 379.00 MEASURING AND REGULATING STATION - CITY GATE CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 37-S0.5 NET SALVAGE PERCENT.. -15 1962 553.69 552 532 105 4.95 21 1966 2,027.19 1,934 1,865 466 6.31 74 1978 3,664.52 2,999 2,892 1,322 10.67 124 1979 39,991.93 32,243 31,096 14,895 11.06 1,347 1981 3,842.41 3,004 2,897 1,522 11.85 128 1988 5,683.89 3,918 3,779 2,757 14.82 186 1989 15,810.50 10,678 10,298 7,884 15.27 516 1990 47,501.81 31,403 30,286 24,341 15.73 1,547 1991 9,944.62 6,429 6,200 5,236 16.20 323 1992 10,171.27 6,424 6,196 5,501 16.68 330 1993 51,670.93 31,847 30,714 28,708 17.17 1,672 1994 4.23 3 3 2 17.66 1995 88,991.22 52,083 50,231 52,109 18.17 2,868 1996 249,013.50 141,711 136,671 149,695 18.69 8,009 1997 30,371.48 16,793 16,196 18,731 19.21 975 1998 28,563.39 15,314 14,769 18,079 19.75 915 1999 81,629.12 42,370 40,863 53,010 20.30 2,611 2000 100,467.76 50,369 48,578 66,960 20.87 3,208 2001 86,476.95 41,822 40,335 59,113 21.44 2,757 2002 5,727.21 2,665 2,570 4,016 22.03 182 2003 98,337.96 43,921 42,359 70,730 22.63 3,125 2004 24,140.44 10,317 9,950 17,812 23.25 766 2006 252,720.38 98,029 94,543 196,085 24.52 7,997 2008 3,128,266.59 1,083,137 1,044,617 2,552,890 25.86 98,720 2009 894,035.01 290,100 279,783 748,357 26.56 28,176 2010 112,457.96 34,009 32,799 96,528 27.27 3,540 2011 33,501.08 9,361 9,028 29,498 28.01 1,053 2012 54,561.41 13,973 13,476 49,270 28.76 1,713 2013 2,483.38 577 556 2,300 29.53 78 2014 351,931.81 73,068 70,470 334,252 30.32 11,024 2015 176,523.76 32,206 31,061 171,941 31.13 5,523 2016 199,295.68 31,158 30,050 199,140 31.97 6,229 2017 17,438.66 2,260 2,180 17,874 32.83 544 2018 192,859.89 19,721 19,019 202,770 33.71 6,015 2019 21,978.30 1,633 1,575 23,700 34.61 685 2020 57,056.91 2,571 2,480 63,135 35.55 1,776 2021 122,981.50 1,873 1,806 139,623 36.51 3,824 6,602,678.34 2,242,475 2,162,723 5,430,357 208,581 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 26.0 3.16 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-229 Attachment C J. Spanos, Avista Page 709 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 380.00 SERVICES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 52-R3 NET SALVAGE PERCENT.. -25 1958 15,162.23 16,693 18,953 1959 141,647.80 154,927 177,060 1960 213,107.87 231,499 266,385 1961 275,807.13 297,486 344,018 741 7.13 104 1962 330,706.55 354,079 409,463 3,920 7.46 525 1963 380,697.20 404,400 467,655 8,216 7.81 1,052 1964 397,927.26 419,162 484,726 12,683 8.18 1,550 1965 445,405.07 465,103 537,853 18,903 8.56 2,208 1966 509,878.60 527,527 610,041 27,307 8.96 3,048 1967 608,935.69 624,014 721,620 39,550 9.37 4,221 1968 803,846.00 815,251 942,770 62,038 9.81 6,324 1969 974,843.05 978,121 1,131,115 87,439 10.26 8,522 1970 222,925.04 221,156 255,748 22,908 10.73 2,135 1971 849,130.69 832,392 962,592 98,821 11.22 8,808 1972 859,006.77 831,755 961,855 111,903 11.72 9,548 1973 625,874.04 598,038 691,581 90,762 12.25 7,409 1974 559,795.21 527,635 610,166 89,578 12.79 7,004 1975 404,223.70 375,559 434,303 70,977 13.35 5,317 1976 441,614.73 404,144 467,359 84,659 13.93 6,077 1977 418,010.94 376,612 435,520 86,994 14.52 5,991 1978 440,957.10 390,820 451,951 99,245 15.13 6,559 1979 1,471,511.84 1,281,908 1,482,419 356,971 15.76 22,650 1980 930,101.48 795,958 920,459 242,168 16.40 14,766 1981 794,288.37 667,123 771,472 221,388 17.06 12,977 1982 215,468.96 177,503 205,267 64,069 17.73 3,614 1983 849,833.26 686,198 793,531 268,761 18.41 14,599 1984 1,198,135.64 947,276 1,095,446 402,224 19.11 21,048 1985 1,172,684.21 907,145 1,049,037 416,818 19.82 21,030 1986 1,433,220.84 1,083,533 1,253,015 538,511 20.55 26,205 1987 1,726,576.40 1,275,012 1,474,445 683,776 21.28 32,132 1988 1,983,862.43 1,429,249 1,652,807 827,021 22.03 37,541 1989 1,966,118.38 1,380,535 1,596,473 861,175 22.79 37,787 1990 3,100,451.97 2,119,624 2,451,168 1,424,397 23.56 60,458 1991 6,761,668.18 4,495,833 5,199,055 3,253,030 24.34 133,650 1992 7,796,181.36 5,035,651 5,823,310 3,921,917 25.13 156,065 1993 8,691,407.07 5,446,796 6,298,764 4,565,495 25.93 176,070 1994 7,454,048.14 4,526,191 5,234,162 4,083,398 26.74 152,707 1995 5,856,274.09 3,440,561 3,978,721 3,341,622 27.56 121,249 1996 6,862,313.51 3,894,706 4,503,902 4,073,990 28.39 143,501 1997 6,869,246.67 3,759,882 4,347,989 4,238,569 29.23 145,007 1998 5,412,002.10 2,851,719 3,297,775 3,467,228 30.08 115,267 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-230 Attachment C J. Spanos, Avista Page 710 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 380.00 SERVICES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 52-R3 NET SALVAGE PERCENT.. -25 1999 4,705,520.06 2,383,287 2,756,072 3,125,828 30.93 101,061 2000 4,999,203.60 2,427,488 2,807,187 3,441,818 31.80 108,233 2001 3,775,284.78 1,754,233 2,028,624 2,690,482 32.67 82,353 2002 3,837,717.75 1,701,164 1,967,254 2,829,893 33.56 84,323 2003 4,560,287.41 1,923,871 2,224,796 3,475,563 34.45 100,887 2004 6,001,261.44 2,401,930 2,777,631 4,723,946 35.35 133,634 2005 2,403,551.80 909,985 1,052,322 1,952,118 36.25 53,852 2006 4,030,285.90 1,437,704 1,662,585 3,375,272 37.16 90,831 2007 3,833,637.13 1,282,783 1,483,431 3,308,615 38.08 86,886 2008 5,620,550.85 1,755,087 2,029,612 4,996,077 39.01 128,072 2009 4,846,208.80 1,404,916 1,624,668 4,433,093 39.94 110,994 2010 4,712,925.94 1,259,824 1,456,881 4,434,276 40.88 108,471 2011 9,849,230.86 2,407,891 2,784,525 9,527,014 41.83 227,756 2012 3,986,967.47 883,662 1,021,881 3,961,828 42.78 92,609 2013 9,965,174.08 1,981,077 2,290,950 10,165,518 43.73 232,461 2014 17,158,098.46 3,015,107 3,486,719 17,960,904 44.69 401,900 2015 12,813,706.61 1,956,012 2,261,965 13,755,168 45.65 301,318 2016 22,577,119.35 2,919,786 3,376,489 24,844,910 46.62 532,924 2017 24,784,498.50 2,627,467 3,038,446 27,942,177 47.59 587,144 2018 21,529,732.31 1,775,126 2,052,785 24,859,380 48.57 511,826 2019 19,610,448.47 1,159,713 1,341,111 23,171,950 49.54 467,742 2020 19,604,051.34 697,414 806,501 23,698,563 50.52 469,093 2021 23,612,755.01 278,040 321,530 29,194,414 51.51 566,772 321,283,115.49 96,392,343 111,465,916 290,137,978 7,115,867 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 40.8 2.21 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-231 Attachment C J. Spanos, Avista Page 711 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 381.00 METERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 IDAHO SURVIVOR CURVE.. IOWA 35-R1 NET SALVAGE PERCENT.. -3 1956 26,571.78 26,102 27,369 1957 37,594.20 36,576 38,722 1958 20,933.62 20,169 21,562 1959 33,143.11 31,641 34,137 1960 10,422.52 9,861 10,735 1961 21,668.32 20,310 22,285 33 3.15 10 1962 23,086.26 21,435 23,519 260 3.45 75 1963 32,521.56 29,908 32,816 681 3.75 182 1964 43,282.18 39,409 43,241 1,340 4.06 330 1965 73,604.14 66,346 72,797 3,015 4.37 690 1966 64,007.58 57,093 62,645 3,283 4.69 700 1967 62,925.55 55,517 60,915 3,898 5.02 776 1968 76,702.95 66,927 73,435 5,569 5.35 1,041 1969 79,875.89 68,897 75,596 6,676 5.69 1,173 1970 108,121.77 92,178 101,141 10,224 6.03 1,696 1971 87,206.17 73,449 80,591 9,231 6.38 1,447 1972 106,726.83 88,760 97,391 12,538 6.74 1,860 1973 81,185.80 66,635 73,114 10,507 7.11 1,478 1974 58,808.12 47,627 52,258 8,314 7.48 1,111 1975 31,516.91 25,172 27,620 4,843 7.86 616 1976 29,566.36 23,275 25,538 4,915 8.25 596 1977 40,515.52 31,418 34,473 7,258 8.65 839 1978 33,791.80 25,796 28,304 6,501 9.06 718 1979 84,158.20 63,229 69,377 17,306 9.47 1,827 1980 45,487.24 33,613 36,881 9,970 9.89 1,008 1981 62,062.71 45,076 49,459 14,465 10.32 1,402 1982 37,723.37 26,910 29,527 9,328 10.76 867 1983 38,377.69 26,868 29,481 10,048 11.21 896 1984 69,817.87 47,935 52,596 19,316 11.67 1,655 1985 82,046.98 55,196 60,563 23,945 12.14 1,972 1986 70,820.43 46,664 51,202 21,744 12.61 1,724 1987 63,660.03 41,028 45,017 20,552 13.10 1,569 1988 78,001.39 49,146 53,925 26,417 13.59 1,944 1989 87,149.16 53,601 58,813 30,951 14.10 2,195 1990 215,296.53 129,188 141,750 80,005 14.61 5,476 1991 229,778.32 134,295 147,354 89,318 15.14 5,899 1992 354,175.39 201,370 220,951 143,850 15.68 9,174 1993 362,458.66 200,319 219,798 153,535 16.22 9,466 1994 310,253.17 166,354 182,530 137,031 16.78 8,166 1995 433,669.34 225,381 247,297 199,383 17.34 11,498 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-232 Attachment C J. Spanos, Avista Page 712 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 381.00 METERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 IDAHO SURVIVOR CURVE.. IOWA 35-R1 NET SALVAGE PERCENT.. -3 1996 438,775.56 220,546 241,992 209,947 17.92 11,716 1997 373,336.19 181,282 198,910 185,627 18.50 10,034 1998 377,370.53 176,579 193,749 194,942 19.10 10,206 1999 354,432.15 159,585 175,103 189,962 19.70 9,643 2000 270,421.50 116,904 128,272 150,263 20.31 7,398 2001 290,403.20 120,244 131,936 167,179 20.93 7,988 2002 150,105.45 59,370 65,143 89,466 21.56 4,150 2003 193,261.84 72,798 79,877 119,183 22.20 5,369 2004 132,929.51 47,569 52,195 84,723 22.84 3,709 2005 1,894,176.45 641,041 703,375 1,247,627 23.50 53,091 2006 1,531,870.50 489,126 536,688 1,041,139 24.15 43,111 2007 1,694,611.48 507,682 557,048 1,188,402 24.82 47,881 2008 8,004,119.61 2,240,043 2,457,861 5,786,382 25.49 227,006 2009 941,835.40 245,016 268,841 701,250 26.16 26,806 2010 2,109,128.60 506,474 555,723 1,616,680 26.84 60,234 2011 2,752,529.72 605,890 664,806 2,170,300 27.52 78,863 2012 1,369,421.84 273,638 300,246 1,110,258 28.21 39,357 2013 2,174,348.01 390,336 428,292 1,811,287 28.90 62,674 2014 43,618.83 6,932 7,606 37,321 29.60 1,261 2015 130,671.57 18,074 19,831 114,760 30.30 3,787 2016 173,657.75 20,391 22,374 156,494 31.01 5,047 2017 173,452.68 16,742 18,370 160,286 31.72 5,053 2018 113,301.34 8,535 9,365 107,335 32.44 3,309 2019 1,024,751.73 55,487 60,882 994,612 33.16 29,994 2020 123,228.43 4,025 4,416 122,509 33.89 3,615 2021 1,293,246.85 14,080 15,449 1,316,595 34.63 38,019 31,937,722.14 9,769,063 10,715,075 22,180,779 881,397 WASHINGTON SURVIVOR CURVE.. IOWA 35-R1 NET SALVAGE PERCENT.. -3 1971 85,178.77 71,741 61,957 25,777 6.38 4,040 1972 136,090.07 113,180 97,744 42,429 6.74 6,295 1973 122,747.08 100,747 87,007 39,423 7.11 5,545 1974 98,335.15 79,640 68,778 32,507 7.48 4,346 1976 30,456.31 23,976 20,706 10,664 8.25 1,293 1977 64,636.75 50,122 43,286 23,290 8.65 2,692 1978 41,673.48 31,812 27,473 15,450 9.06 1,705 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-233 Attachment C J. Spanos, Avista Page 713 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 381.00 METERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 WASHINGTON SURVIVOR CURVE.. IOWA 35-R1 NET SALVAGE PERCENT.. -3 1979 167,261.38 125,666 108,527 63,752 9.47 6,732 1980 72,305.48 53,430 46,143 28,332 9.89 2,865 1981 79,404.34 57,671 49,806 31,981 10.32 3,099 1982 84,913.16 60,573 52,312 35,149 10.76 3,267 1983 46,867.01 32,812 28,337 19,936 11.21 1,778 1984 71,445.38 49,052 42,362 31,227 11.67 2,676 1985 149,563.10 100,616 86,894 67,156 12.14 5,532 1986 125,856.79 82,927 71,617 58,015 12.61 4,601 1987 83,372.16 53,732 46,404 39,469 13.10 3,013 1988 141,540.85 89,179 77,016 68,771 13.59 5,060 1989 100,271.35 61,672 53,261 50,019 14.10 3,547 1990 414,122.28 248,493 214,603 211,943 14.61 14,507 1991 543,844.13 317,851 274,501 285,658 15.14 18,868 1992 846,872.41 481,498 415,830 456,449 15.68 29,110 1993 856,014.67 473,091 408,569 473,126 16.22 29,169 1994 728,034.71 390,363 337,124 412,752 16.78 24,598 1995 906,053.22 470,882 406,662 526,573 17.34 30,368 1996 1,140,743.62 573,383 495,183 679,783 17.92 37,934 1997 967,968.36 470,019 405,916 591,091 18.50 31,951 1998 992,026.24 464,188 400,881 620,906 19.10 32,508 1999 903,971.74 407,017 351,507 579,584 19.70 29,421 2000 735,995.95 318,172 274,779 483,297 20.31 23,796 2001 704,625.96 291,757 251,966 473,799 20.93 22,637 2002 382,811.61 151,410 130,760 263,536 21.56 12,223 2003 423,145.20 159,391 137,653 298,187 22.20 13,432 2005 164,155.88 55,555 47,978 121,102 23.50 5,153 2006 1,851,243.23 591,102 510,486 1,396,295 24.15 57,818 2007 1,922,558.71 575,971 497,418 1,482,817 24.82 59,743 2008 2,230,469.23 624,222 539,089 1,758,295 25.49 68,980 2009 1,165,638.53 303,237 261,881 938,727 26.16 35,884 2010 1,359,184.76 326,387 281,873 1,118,087 26.84 41,657 2011 1,198,060.69 263,719 227,752 1,006,250 27.52 36,564 2012 1,125,993.95 224,996 194,310 965,463 28.21 34,224 2013 4,886,402.76 877,201 757,565 4,275,429 28.90 147,939 2014 2,366,826.09 376,133 324,835 2,112,996 29.60 71,385 2016 658,159.28 77,281 66,741 611,163 31.01 19,709 2017 1,267,968.53 122,386 105,695 1,200,313 31.72 37,841 2018 1,012,982.01 76,312 65,904 977,467 32.44 30,132 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-234 Attachment C J. Spanos, Avista Page 714 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 381.00 METERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 WASHINGTON SURVIVOR CURVE.. IOWA 35-R1 NET SALVAGE PERCENT.. -3 2019 11,966,483.68 647,950 559,580 11,765,898 33.16 354,822 2020 4,230,627.14 138,178 119,333 4,238,213 33.89 125,058 2021 3,087,081.69 33,609 29,025 3,150,669 34.63 90,981 52,741,984.87 11,770,302 10,165,030 44,159,214 1,636,498 84,679,707.01 21,539,365 20,880,105 66,339,993 2,517,895 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 26.3 2.97 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-235 Attachment C J. Spanos, Avista Page 715 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 381.00 METERS - WASHINGTON AMI CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 15-S2.5 NET SALVAGE PERCENT.. -3 2018 22,677,528.40 5,419,022 3,624,919 19,732,935 11.52 1,712,928 2020 1,175,992.77 121,127 81,025 1,130,248 13.50 83,722 2021 2,729,842.09 93,715 62,689 2,749,049 14.50 189,590 26,583,363.26 5,633,864 3,768,633 23,612,231 1,986,240 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 11.9 7.47 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-236 Attachment C J. Spanos, Avista Page 716 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 385.00 INDUSTRIAL MEASURING AND REGULATING STATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-R2.5 NET SALVAGE PERCENT.. -15 1956 2,067.06 1,818 2,377 1957 282,515.34 246,119 324,893 1958 21,574.00 18,611 24,810 1959 21,778.10 18,603 24,915 130 16.72 8 1960 15,162.00 12,817 17,166 270 17.22 16 1961 194.72 163 218 6 17.73 1963 61.00 50 67 3 18.80 1964 31.00 25 33 3 19.35 1965 46.00 37 50 3 19.91 1966 4,260.70 3,356 4,495 405 20.48 20 1967 727.99 566 758 79 21.07 4 1968 81.00 62 83 10 21.67 1969 984.95 744 996 137 22.28 6 1988 57,525.99 29,872 40,008 26,147 35.65 733 1989 63,358.31 32,014 42,877 29,985 36.44 823 1990 2,812.18 1,382 1,851 1,383 37.23 37 1991 7,383.52 3,524 4,720 3,771 38.02 99 1992 67,357.36 31,187 41,769 35,692 38.83 919 1993 142,726.50 64,037 85,766 78,369 39.64 1,977 1994 42,007.38 18,238 24,427 23,881 40.46 590 1995 25,534.67 10,716 14,352 15,013 41.28 364 1996 55,789.67 22,593 30,259 33,899 42.11 805 1997 105,167.39 41,027 54,948 65,994 42.95 1,537 1998 148,604.14 55,765 74,687 96,208 43.79 2,197 1999 111,415.85 40,134 53,752 74,376 44.64 1,666 2000 228,888.50 78,967 105,762 157,460 45.50 3,461 2001 297,945.47 98,258 131,599 211,038 46.36 4,552 2002 23,166.03 7,287 9,760 16,881 47.22 357 2003 141,466.92 42,299 56,652 106,035 48.10 2,204 2004 266,004.61 75,442 101,041 204,864 48.97 4,183 2005 73,300.64 19,648 26,315 57,981 49.85 1,163 2006 12,445.90 3,140 4,205 10,108 50.74 199 2007 151,220.49 35,770 47,907 125,997 51.63 2,440 2008 144,333.29 31,844 42,649 123,334 52.53 2,348 2009 21,516.79 4,404 5,898 18,846 53.43 353 2010 175,841.68 33,194 44,458 157,760 54.33 2,904 2011 109,590.96 18,923 25,344 100,686 55.24 1,823 2012 231,066.83 36,179 48,455 217,272 56.15 3,869 2013 22,297.84 3,128 4,189 21,454 57.07 376 2014 447,414.74 55,492 74,322 440,205 57.99 7,591 2015 76,615.02 8,255 11,056 77,051 58.91 1,308 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-237 Attachment C J. Spanos, Avista Page 717 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 385.00 INDUSTRIAL MEASURING AND REGULATING STATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-R2.5 NET SALVAGE PERCENT.. -15 2016 14,345.86 1,310 1,755 14,743 59.84 246 2017 100,577.97 7,527 10,081 105,584 60.77 1,737 2018 112,786.62 6,566 8,794 120,911 61.71 1,959 2019 56,535.54 2,361 3,162 61,854 62.64 987 2020 63,954.76 1,607 2,153 71,395 63.58 1,123 2021 145,286.31 1,208 1,618 165,462 64.53 2,564 4,095,769.59 1,226,269 1,637,452 3,072,683 59,548 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 51.6 1.45 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-238 Attachment C J. Spanos, Avista Page 718 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 389.42 LAND EASEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 50-R3 NET SALVAGE PERCENT.. 0 2018 2,368.16 162 153 2,215 46.57 48 2,368.16 162 153 2,215 48 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 46.1 2.03 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-239 Attachment C J. Spanos, Avista Page 719 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 30-R3 NET SALVAGE PERCENT.. -5 1981 2,741.22 2,636 2,439 439 2.53 174 1992 47,715.78 39,597 36,643 13,459 6.29 2,140 1993 111,624.05 90,678 83,913 33,292 6.79 4,903 1997 8,878.28 6,494 6,010 3,312 9.10 364 2000 66,382.73 43,865 40,592 29,110 11.12 2,618 2003 15,101.12 8,805 8,148 7,708 13.34 578 2004 59,637.12 33,146 30,673 31,946 14.12 2,262 2007 29,112.56 13,705 12,683 17,885 16.55 1,081 2009 48,669.49 19,998 18,506 32,597 18.26 1,785 2011 941,444.66 328,514 304,005 684,512 20.03 34,174 2012 18,942.78 6,013 5,564 14,326 20.93 684 2013 272,852.23 77,832 72,025 214,470 21.85 9,816 2014 54,141.77 13,682 12,661 44,188 22.78 1,940 2017 1,430,700.52 219,326 202,963 1,299,273 25.62 50,713 2018 15,890,855.32 1,902,135 1,760,225 14,925,173 26.58 561,519 2019 5,146,283.54 441,312 408,388 4,995,210 27.55 181,314 2020 52,220.56 2,687 2,486 52,346 28.53 1,835 2021 1,199,686.90 20,570 19,035 1,240,636 29.51 42,041 25,396,990.63 3,270,995 3,026,959 23,639,881 899,941 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 26.3 3.54 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-240 Attachment C J. Spanos, Avista Page 720 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 391.10 OFFICE FURNITURE AND EQUIPMENT - COMPUTER HARDWARE CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 5-SQUARE NET SALVAGE PERCENT.. 0 2017 2,463.46 2,217 2,197 266 0.50 266 2019 121,086.56 60,543 60,005 61,082 2.50 24,433 2020 19,769.82 5,931 5,878 13,892 3.50 3,969 143,319.84 68,691 68,080 75,240 28,668 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 2.6 20.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-241 Attachment C J. Spanos, Avista Page 721 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 392.20 TRANSPORTATION EQUIPMENT - LIGHT TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 14-L2.5 NET SALVAGE PERCENT.. +10 1991 21,954.40 17,444 19,759 1992 29,977.31 23,530 26,980 1995 52,211.53 39,505 46,990 1996 5,806.97 4,334 5,226 1999 28,447.46 20,190 25,603 2000 5,620.92 3,910 5,059 2004 7,765.83 4,932 6,989 2005 28,432.91 17,657 25,590 2006 73,017.79 44,358 65,716 2008 67,331.12 39,302 60,598 2009 36,210.20 20,648 32,589 2010 36,650.20 20,309 32,985 2011 697,751.30 371,850 627,976 2012 39,610.95 20,015 35,650 2013 640,662.34 301,888 576,596 2014 135,073.56 58,092 121,566 2015 1,051,779.29 403,659 847,661 98,940 8.03 12,321 2016 808,893.43 268,845 564,559 163,445 8.83 18,510 2017 528,466.59 146,424 307,482 168,138 9.69 17,352 2018 664,130.70 145,162 304,832 292,886 10.60 27,631 2019 51,291.12 8,111 17,033 29,129 11.54 2,524 2020 566,637.07 54,276 113,976 395,997 12.51 31,654 2021 518,943.68 16,678 35,023 432,026 13.50 32,002 6,096,666.67 2,051,119 3,906,438 1,580,562 141,994 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 11.1 2.33 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-242 Attachment C J. Spanos, Avista Page 722 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 392.30 TRANSPORTATION EQUIPMENT - MEDIUM TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 17-L2.5 NET SALVAGE PERCENT.. +10 1997 55,341.73 37,443 49,808 2004 120,625.45 71,716 108,563 2005 6,308.62 3,687 5,678 2006 157,776.72 90,546 141,999 2008 19,625.67 10,723 17,663 2009 147,178.70 77,606 132,461 2010 1,007,105.36 507,581 906,395 2011 135,169.88 64,404 121,653 2012 381,453.82 169,433 326,087 17,221 8.61 2,000 2013 235,885.84 96,158 185,063 27,234 9.30 2,928 2014 341,759.11 125,568 241,665 65,918 10.06 6,552 2015 308,052.95 99,809 192,090 85,158 10.88 7,827 2016 733,549.49 204,271 393,136 267,059 11.74 22,748 2018 304,534.09 55,299 106,427 167,654 13.57 12,355 2019 82,618.08 10,803 20,791 53,565 14.53 3,687 2020 495,369.70 39,077 75,207 370,626 15.51 23,896 2021 340,655.06 9,017 17,354 289,235 16.50 17,529 4,873,010.27 1,673,141 3,042,040 1,343,669 99,522 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 13.5 2.04 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-243 Attachment C J. Spanos, Avista Page 723 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 392.40 TRANSPORTATION EQUIPMENT - HEAVY TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 20-R4 NET SALVAGE PERCENT.. +10 2004 760,980.36 536,263 684,882 2006 101,711.45 65,406 89,014 2,526 5.71 442 2013 396,421.17 149,312 203,206 153,573 11.63 13,205 2014 562,411.59 187,536 255,226 250,944 12.59 19,932 2015 178,982.16 51,950 70,701 90,383 13.55 6,670 2016 207,901.68 51,175 69,646 117,466 14.53 8,084 2018 422,266.73 66,317 90,254 289,786 16.51 17,552 2021 467,363.26 10,516 14,312 406,315 19.50 20,837 3,098,038.40 1,118,475 1,477,241 1,310,993 86,722 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 15.1 2.80 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-244 Attachment C J. Spanos, Avista Page 724 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 392.50 TRANSPORTATION EQUIPMENT - OTHER CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 16-L2 NET SALVAGE PERCENT.. +10 1979 8,678.82 7,533 7,811 1990 17,413.72 13,145 15,672 1991 9,574.04 7,114 8,617 1992 7,932.55 5,805 7,139 1993 1,629.00 1,172 1,466 1994 5,363.67 3,792 4,827 1995 9,467.40 6,572 8,521 1996 3,445.68 2,347 3,101 1997 13,310.34 8,887 11,979 1998 2,910.54 1,904 2,619 2006 60,163.72 32,657 45,048 9,099 6.35 1,433 2007 3,380.59 1,789 2,468 575 6.59 87 2008 83,144.00 42,794 59,031 15,799 6.85 2,306 2009 41,319.10 20,592 28,405 8,782 7.14 1,230 2010 40,193.35 19,308 26,634 9,540 7.46 1,279 2011 43,564.92 19,996 27,583 11,625 7.84 1,483 2012 188,394.16 81,705 112,706 56,849 8.29 6,858 2013 143,062.62 57,861 79,815 48,941 8.81 5,555 2014 44,984.97 16,625 22,933 17,553 9.43 1,861 2015 207,547.51 68,413 94,371 92,422 10.14 9,115 2016 195,147.59 55,763 76,921 98,712 10.92 9,040 2017 155,638.11 37,120 51,204 88,870 11.76 7,557 2018 88,852.48 16,793 23,165 56,802 12.64 4,494 2019 181,724.15 24,942 34,405 129,147 13.56 9,524 2020 47,017.65 3,940 5,435 36,881 14.51 2,542 2021 76,242.54 2,144 2,957 65,661 15.50 4,236 1,680,103.22 560,713 764,833 747,260 68,600 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 10.9 4.08 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-245 Attachment C J. Spanos, Avista Page 725 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 393.00 STORES EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 25-SQUARE NET SALVAGE PERCENT.. 0 2004 20,449.62 14,315 14,313 6,137 7.50 818 2005 597.50 394 394 204 8.50 24 2006 39,536.69 24,513 24,511 15,026 9.50 1,582 2015 3,888.34 1,011 1,011 2,877 18.50 156 2021 157,881.00 3,158 3,157 154,724 24.50 6,315 222,353.15 43,391 43,386 178,967 8,895 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 20.1 4.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-246 Attachment C J. Spanos, Avista Page 726 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 394.00 TOOLS, SHOP AND GARAGE EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 20-SQUARE NET SALVAGE PERCENT.. 0 2002 3,192.99 3,113 3,113 80 0.50 80 2003 283,542.01 262,276 262,304 21,238 1.50 14,159 2004 119,555.68 104,611 104,622 14,934 2.50 5,974 2005 99,629.51 82,194 82,203 17,427 3.50 4,979 2006 54,057.88 41,895 41,899 12,159 4.50 2,702 2007 232,351.79 168,455 168,473 63,879 5.50 11,614 2008 99,703.88 67,300 67,307 32,397 6.50 4,984 2010 101,469.46 58,345 58,351 43,118 8.50 5,073 2011 27,747.12 14,567 14,569 13,178 9.50 1,387 2012 257,501.53 122,313 122,326 135,176 10.50 12,874 2013 888,283.21 377,520 377,559 510,724 11.50 44,411 2015 3,618.24 1,176 1,176 2,442 13.50 181 2017 21,232.43 4,777 4,777 16,455 15.50 1,062 2018 83,761.93 14,658 14,660 69,102 16.50 4,188 2019 380,888.51 47,611 47,616 333,273 17.50 19,044 2020 368,628.91 27,647 27,649 340,980 18.50 18,431 2021 389,399.91 9,735 9,736 379,664 19.50 19,470 3,414,564.99 1,408,193 1,408,340 2,006,225 170,613 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 11.8 5.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-247 Attachment C J. Spanos, Avista Page 727 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 395.00 LABORATORY EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2013 93,418.63 52,938 52,930 40,489 6.50 6,229 2019 39,610.12 6,602 6,601 33,009 12.50 2,641 2021 27,300.70 910 910 26,391 14.50 1,820 160,329.45 60,450 60,441 99,889 10,690 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 9.3 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-248 Attachment C J. Spanos, Avista Page 728 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 395.12 LABORATORY EQUIPMENT - AMI CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2018 40,840.58 9,529 9,510 31,331 11.50 2,724 40,840.58 9,529 9,510 31,331 2,724 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 11.5 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-249 Attachment C J. Spanos, Avista Page 729 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 396.40 POWER OPERATED EQUIPMENT - HEAVY TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 24-S1 NET SALVAGE PERCENT.. 0 1978 158,711.24 150,709 158,711 1986 68,032.29 57,912 68,032 1987 107,340.79 89,987 107,341 1989 264,725.79 214,648 264,726 1991 157,908.93 123,497 157,909 2002 319,867.31 190,321 319,867 2005 123,603.78 65,665 123,604 2010 744,251.60 302,352 649,342 94,910 14.25 6,660 2012 305,686.05 106,480 228,681 77,005 15.64 4,924 2,250,127.78 1,301,571 2,078,213 171,915 11,584 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 14.8 0.51 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-250 Attachment C J. Spanos, Avista Page 730 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 396.50 POWER OPERATED EQUIPMENT - OTHER CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 16-S0 NET SALVAGE PERCENT.. 0 2000 10,792.97 8,081 10,793 2004 15,473.56 9,961 15,474 2005 143,490.69 88,426 143,491 2006 91,891.20 54,043 91,891 2007 62,178.83 34,820 62,179 2010 171,647.49 80,674 147,116 24,531 8.48 2,893 2011 326,198.86 142,914 260,617 65,582 8.99 7,295 2012 253,654.69 102,887 187,624 66,031 9.51 6,943 2013 53,284.76 19,816 36,136 17,149 10.05 1,706 2014 53,284.88 17,951 32,735 20,550 10.61 1,937 2015 436,887.87 131,066 239,011 197,877 11.20 17,668 2016 34,312.90 8,986 16,387 17,926 11.81 1,518 2017 6,570.03 1,454 2,651 3,919 12.46 315 2018 99,966.89 17,869 32,586 67,381 13.14 5,128 2019 103,585.93 13,789 25,145 78,441 13.87 5,655 2020 115,835.96 9,701 17,691 98,145 14.66 6,695 1,979,057.51 742,438 1,321,527 657,531 57,753 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 11.4 2.92 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-251 Attachment C J. Spanos, Avista Page 731 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 397.00 COMMUNICATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 FULLY ACCRUED NET SALVAGE PERCENT.. 0 2006 29.12 29 29 29.12 29 29 AMORTIZED SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2007 1,278.18 1,236 1,234 44 0.50 44 2008 8,875.27 7,988 7,978 897 1.50 598 2009 1,365.01 1,138 1,137 228 2.50 91 2010 126,745.20 97,172 97,053 29,693 3.50 8,484 2011 152,629.45 106,841 106,710 45,920 4.50 10,204 2012 100,412.80 63,594 63,516 36,897 5.50 6,709 2013 9,703.14 5,498 5,491 4,212 6.50 648 2014 106,160.50 53,080 53,015 53,146 7.50 7,086 2015 6,202.45 2,688 2,685 3,518 8.50 414 2016 1,206.65 442 441 765 9.50 81 2017 563.15 169 169 394 10.50 38 2019 368,973.65 61,497 61,421 307,552 12.50 24,604 884,115.45 401,343 400,850 483,265 59,001 884,144.57 401,372 400,879 483,265 59,001 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 8.2 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-252 Attachment C J. Spanos, Avista Page 732 of 800 AVISTA CORPORATION GAS PLANT - WASHINGTON AND IDAHO ACCOUNT 397.12 COMMUNICATION EQUIPMENT - AMI CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2018 19,942.47 4,653 4,649 15,293 11.50 1,330 19,942.47 4,653 4,649 15,293 1,330 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 11.5 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-253 Attachment C J. Spanos, Avista Page 733 of 800 AVISTA CORPORATION GAS PLANT - ALLOCATED ALL ACCOUNT 391.10 OFFICE FURNITURE AND EQUIPMENT - COMPUTER HARDWARE CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 5-SQUARE NET SALVAGE PERCENT.. 0 2017 160,963.26 144,867 131,219 29,744 0.50 29,744 2019 96,957.25 48,479 43,912 53,045 2.50 21,218 2020 75,420.74 22,626 20,494 54,927 3.50 15,693 333,341.25 215,972 195,625 137,716 66,655 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 2.1 20.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-254 Attachment C J. Spanos, Avista Page 734 of 800 AVISTA CORPORATION GAS PLANT - ALLOCATED ALL ACCOUNT 392.20 TRANSPORTATION EQUIPMENT - LIGHT TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 14-L2.5 NET SALVAGE PERCENT.. +10 2020 50,237.38 4,812 5,687 39,527 12.51 3,160 50,237.38 4,812 5,687 39,527 3,160 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 12.5 6.29 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-255 Attachment C J. Spanos, Avista Page 735 of 800 AVISTA CORPORATION GAS PLANT - ALLOCATED ALL ACCOUNT 392.50 TRANSORTATION EQUIPMENT - OTHER CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 16-L2 NET SALVAGE PERCENT.. +10 2018 46,950.20 8,874 6,893 35,362 12.64 2,798 46,950.20 8,874 6,893 35,362 2,798 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 12.6 5.96 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-256 Attachment C J. Spanos, Avista Page 736 of 800 AVISTA CORPORATION GAS PLANT - ALLOCATED ALL ACCOUNT 394.00 TOOLS, SHOP AND GARAGE EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 20-SQUARE NET SALVAGE PERCENT.. 0 2002 20,727.97 20,210 20,172 556 0.50 556 2005 57,361.38 47,323 47,234 10,127 3.50 2,893 2006 217,295.52 168,404 168,089 49,207 4.50 10,935 2007 119,617.16 86,722 86,560 33,057 5.50 6,010 2008 409,473.90 276,395 275,877 133,597 6.50 20,553 2009 165,720.59 103,575 103,381 62,340 7.50 8,312 2010 102,657.24 59,028 58,917 43,740 8.50 5,146 2011 25,733.41 13,510 13,485 12,248 9.50 1,289 2012 202,171.14 96,031 95,851 106,320 10.50 10,126 2014 958,195.80 359,323 358,650 599,546 12.50 47,964 2015 339,761.55 110,423 110,216 229,546 13.50 17,003 2018 1,521,248.58 266,219 265,720 1,255,529 16.50 76,093 2019 874,780.15 109,348 109,143 765,637 17.50 43,751 2020 280,759.24 21,057 21,018 259,741 18.50 14,040 2021 375,689.62 9,392 9,374 366,316 19.50 18,785 5,671,193.25 1,746,960 1,743,687 3,927,506 283,456 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 13.9 5.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-257 Attachment C J. Spanos, Avista Page 737 of 800 AVISTA CORPORATION GAS PLANT - ALLOCATED ALL ACCOUNT 395.00 LABORATORY EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2010 74,033.85 56,760 56,765 17,269 3.50 4,934 2014 81,995.78 40,998 41,001 40,995 7.50 5,466 2019 49,141.28 8,190 8,191 40,950 12.50 3,276 2021 28,044.69 935 935 27,110 14.50 1,870 233,215.60 106,883 106,892 126,324 15,546 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 8.1 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-258 Attachment C J. Spanos, Avista Page 738 of 800 AVISTA CORPORATION GAS PLANT - ALLOCATED ALL ACCOUNT 397.00 COMMUNICATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2007 24,581.03 23,762 23,263 1,318 0.50 1,318 2011 66,852.88 46,797 45,813 21,040 4.50 4,676 2017 158,334.41 47,500 46,502 111,832 10.50 10,651 2018 33,151.53 7,735 7,572 25,580 11.50 2,224 282,919.85 125,794 123,150 159,770 18,869 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 8.5 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-259 Attachment C J. Spanos, Avista Page 739 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 350.20 RIGHTS OF WAY CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-R4 NET SALVAGE PERCENT.. 0 2012 668.75 98 24 645 55.52 12 668.75 98 24 645 12 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 53.8 1.79 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-260 Attachment C J. Spanos, Avista Page 740 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 351.10 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 55-R2.5 NET SALVAGE PERCENT.. -5 2012 24,172.36 4,070 740 24,641 46.18 534 24,172.36 4,070 740 24,641 534 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 46.1 2.21 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-261 Attachment C J. Spanos, Avista Page 741 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 351.20 STRUCTURES AND IMPROVEMENTS - COMPRESSOR STATION CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 55-R2.5 NET SALVAGE PERCENT.. -5 2008 264.37 63 60 218 42.59 5 264.37 63 60 218 5 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 43.6 1.89 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-262 Attachment C J. Spanos, Avista Page 742 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 351.40 STRUCTURES AND IMPROVEMENTS - OFFICE CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 55-R2.5 NET SALVAGE PERCENT.. -5 2009 10,261.46 2,257 6,050 4,725 43.48 109 2010 1,042.63 211 566 529 44.38 12 2011 5,079.34 943 2,528 2,805 45.28 62 2012 1,279.73 215 576 768 46.18 17 2019 465.93 21 56 433 52.65 8 2020 45,532.69 1,234 3,308 44,501 53.58 831 2021 45,348.45 407 1,090 46,525 54.53 853 109,010.23 5,288 14,174 100,286 1,892 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 53.0 1.74 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-263 Attachment C J. Spanos, Avista Page 743 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 352.00 WELLS - STORAGE WELLS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 60-R4 NET SALVAGE PERCENT.. 0 2008 879,120.93 196,923 163,479 715,642 46.56 15,370 2009 256.85 53 44 213 47.55 4 2010 5,518.18 1,054 875 4,643 48.54 96 2011 12,939.37 2,258 1,875 11,064 49.53 223 2012 440,801.05 69,647 57,818 382,983 50.52 7,581 2019 465.80 19 16 450 57.50 8 2020 45,519.85 1,138 944 44,576 58.50 762 2021 45,335.66 378 314 45,022 59.50 757 1,429,957.69 271,470 225,365 1,204,593 24,801 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 48.6 1.73 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-264 Attachment C J. Spanos, Avista Page 744 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 352.20 WELLS - RESERVOIRS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 50-R4 NET SALVAGE PERCENT.. 0 2007 10,962.23 3,157 2,954 8,008 35.60 225 2008 30,886.44 8,290 7,758 23,128 36.58 632 2011 1,422,312.87 297,548 278,452 1,143,861 39.54 28,929 1,464,161.54 308,995 289,164 1,174,998 29,786 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 39.4 2.03 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-265 Attachment C J. Spanos, Avista Page 745 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 352.30 WELLS - NON-RECOVERABLE GAS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 50-R4 NET SALVAGE PERCENT.. 0 2007 82,546.36 23,773 25,409 57,137 35.60 1,605 2008 187,214.69 50,248 53,705 133,510 36.58 3,650 2011 180,859.10 37,836 40,439 140,420 39.54 3,551 450,620.15 111,857 119,553 331,067 8,806 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 37.6 1.95 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-266 Attachment C J. Spanos, Avista Page 746 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 353.00 LINES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-R4 NET SALVAGE PERCENT.. 0 2008 61,909.71 12,810 8,964 52,946 51.55 1,027 2010 394.28 70 49 345 53.53 6 2012 108,440.97 15,816 11,067 97,374 55.52 1,754 170,744.96 28,696 20,080 150,665 2,787 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 54.1 1.63 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-267 Attachment C J. Spanos, Avista Page 747 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 354.00 COMPRESSOR STATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 55-R4 NET SALVAGE PERCENT.. 0 2008 2,817,659.52 688,523 679,301 2,138,359 41.56 51,452 2009 482.50 109 108 374 42.55 9 2010 3,588.45 748 738 2,850 43.54 65 2011 24,256.29 4,617 4,555 19,701 44.53 442 2012 298,349.83 51,370 50,682 247,668 45.53 5,440 2019 465.80 21 21 445 52.50 8 2020 45,520.51 1,241 1,224 44,297 53.50 828 2021 45,336.33 412 407 44,930 54.50 824 3,235,659.23 747,041 737,036 2,498,624 59,068 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 42.3 1.83 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-268 Attachment C J. Spanos, Avista Page 748 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 355.00 MEASURING AND REGULATING EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 35-R3 NET SALVAGE PERCENT.. 0 2012 60,049.49 15,665 60,049 2019 465.81 33 450 16 32.55 2020 45,521.11 1,912 26,060 19,461 33.53 580 2021 45,336.94 635 8,654 36,682 34.51 1,063 151,373.35 18,245 95,213 56,160 1,643 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 34.2 1.09 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-269 Attachment C J. Spanos, Avista Page 749 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 356.00 PURIFICATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 35-S2.5 NET SALVAGE PERCENT.. 0 2012 15,105.70 4,070 543 14,562 25.57 569 15,105.70 4,070 543 14,562 569 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 25.6 3.77 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-270 Attachment C J. Spanos, Avista Page 750 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 357.00 OTHER EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 45-R2 NET SALVAGE PERCENT.. 0 2009 288.80 70 120 169 34.15 5 2010 2,582.94 575 984 1,599 34.98 46 2011 2,590.29 529 905 1,685 35.81 47 2012 32,176.43 5,963 10,206 21,970 36.66 599 2019 465.80 23 39 427 42.75 10 2020 45,519.75 1,366 2,338 43,182 43.65 989 2021 45,335.59 453 776 44,560 44.55 1,000 128,959.60 8,979 15,368 113,592 2,696 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 42.1 2.09 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-271 Attachment C J. Spanos, Avista Page 751 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 374.40 LAND - EASEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 60-R4 NET SALVAGE PERCENT.. 0 2009 91,527.94 18,992 18,855 72,673 47.55 1,528 2010 4,950.06 945 938 4,012 48.54 83 2013 205,921.41 29,103 28,894 177,027 51.52 3,436 2014 72,262.29 9,021 8,956 63,306 52.51 1,206 2015 11,578.35 1,252 1,243 10,335 53.51 193 2017 180,985.09 13,543 13,446 167,539 55.51 3,018 2018 38,634.76 2,254 2,238 36,397 56.50 644 2021 3,970.51 33 33 3,938 59.50 66 609,830.41 75,143 74,603 535,228 10,174 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 52.6 1.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-272 Attachment C J. Spanos, Avista Page 752 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 375.00 STRUCTURES AND IMPROVEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 45-R2 NET SALVAGE PERCENT.. 0 1956 2,370.83 2,107 1,546 825 5.01 165 1960 122.31 105 77 45 6.20 7 1963 40,065.31 33,708 24,728 15,337 7.14 2,148 1964 7,674.63 6,401 4,696 2,979 7.47 399 1966 302.59 248 182 121 8.15 15 1971 287.87 224 164 124 10.03 12 1973 828.66 629 461 368 10.86 34 1976 511.06 372 273 238 12.21 19 1979 477.00 332 244 233 13.68 17 2000 3,244.67 1,294 949 2,296 27.05 85 2001 3,770.30 1,441 1,057 2,713 27.80 98 2002 1,584.97 579 425 1,160 28.57 41 2003 7,612.27 2,649 1,943 5,669 29.34 193 2004 431.95 143 105 327 30.12 11 2006 34,994.41 10,335 7,582 27,412 31.71 864 2007 15,892.15 4,411 3,236 12,656 32.51 389 2008 23,844.42 6,189 4,540 19,304 33.32 579 2009 9,093.01 2,192 1,608 7,485 34.15 219 2010 15,687.55 3,493 2,562 13,126 34.98 375 2011 33,719.86 6,886 5,052 28,668 35.81 801 2012 12.96 2 1 12 36.66 2013 40,330.88 6,713 4,925 35,406 37.51 944 2014 42,932.55 6,335 4,647 38,286 38.36 998 2015 153,920.24 19,736 14,479 139,441 39.23 3,554 2016 34,405.33 3,746 2,748 31,657 40.10 789 2017 87,722.61 7,836 5,748 81,975 40.98 2,000 2018 13,531.01 944 693 12,838 41.86 307 2019 49,875.53 2,494 1,830 48,046 42.75 1,124 2020 33,335.15 1,000 733 32,602 43.65 747 2021 13,394.22 134 98 13,296 44.55 298 671,976.30 132,678 97,332 574,644 17,232 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 33.3 2.56 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-273 Attachment C J. Spanos, Avista Page 753 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 376.00 MAINS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 55-R3 NET SALVAGE PERCENT.. -20 1962 8,243.56 8,245 8,864 1,028 9.16 112 1963 537,405.58 532,792 572,770 72,117 9.56 7,544 1964 1,463,412.54 1,437,452 1,545,310 210,785 9.98 21,121 1965 1,019,712.45 992,054 1,066,492 157,163 10.41 15,097 1966 1,089,147.56 1,048,914 1,127,618 179,359 10.86 16,516 1967 684,596.41 652,283 701,226 120,290 11.33 10,617 1968 531,481.61 500,713 538,284 99,494 11.82 8,417 1969 557,020.13 518,577 557,488 110,936 12.33 8,997 1970 374,514.65 344,416 370,259 79,159 12.85 6,160 1971 587,593.92 533,453 573,480 131,633 13.39 9,831 1972 565,758.53 506,840 544,870 134,040 13.94 9,615 1973 765,370.53 676,141 726,875 191,570 14.51 13,203 1974 651,275.23 566,961 609,502 172,028 15.10 11,393 1975 586,760.52 502,990 540,731 163,382 15.71 10,400 1976 456,849.21 385,546 414,475 133,744 16.32 8,195 1977 444,639.50 369,037 396,727 136,840 16.96 8,068 1978 522,711.56 426,420 458,416 168,838 17.61 9,588 1979 870,147.47 697,322 749,645 294,532 18.27 16,121 1980 928,873.22 730,808 785,644 329,004 18.94 17,371 1981 884,479.64 682,560 733,775 327,601 19.63 16,689 1983 570,678.10 422,838 454,565 230,249 21.04 10,943 1984 570,592.20 413,688 444,729 239,982 21.77 11,024 1985 849,528.55 602,394 647,594 371,840 22.50 16,526 1986 989,230.18 685,263 736,681 450,395 23.25 19,372 1987 1,246,844.88 843,042 906,299 589,915 24.01 24,570 1988 1,907,293.64 1,257,990 1,352,382 936,370 24.77 37,803 1989 1,786,136.26 1,147,664 1,233,778 909,586 25.55 35,600 1990 1,174,316.86 734,310 789,408 619,772 26.34 23,530 1991 1,444,418.42 878,004 943,884 789,418 27.14 29,087 1992 2,089,490.86 1,233,635 1,326,200 1,181,189 27.94 42,276 1993 3,693,012.11 2,114,279 2,272,922 2,158,693 28.76 75,059 1994 3,810,885.48 2,112,755 2,271,284 2,301,779 29.59 77,789 1995 2,296,983.09 1,231,854 1,324,285 1,432,095 30.42 47,077 1996 4,779,267.21 2,475,507 2,661,254 3,073,867 31.26 98,332 1997 4,463,415.74 2,229,101 2,396,360 2,959,739 32.11 92,175 1998 3,139,631.23 1,509,095 1,622,329 2,145,228 32.97 65,066 1999 2,234,244.01 1,031,497 1,108,894 1,572,199 33.84 46,460 2000 3,032,128.79 1,341,644 1,442,313 2,196,242 34.72 63,256 2001 3,682,146.92 1,558,564 1,675,509 2,743,067 35.60 77,052 2002 4,373,961.63 1,766,468 1,899,013 3,349,741 36.49 91,799 2003 3,125,766.01 1,200,969 1,291,083 2,459,836 37.39 65,789 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-274 Attachment C J. Spanos, Avista Page 754 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 376.00 MAINS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 55-R3 NET SALVAGE PERCENT.. -20 2004 3,528,663.54 1,285,732 1,382,206 2,852,190 38.30 74,470 2005 3,931,855.44 1,354,556 1,456,194 3,262,033 39.21 83,194 2006 9,751,674.20 3,163,755 3,401,144 8,300,865 40.13 206,849 2007 16,287,794.68 4,953,770 5,325,472 14,219,882 41.06 346,320 2008 14,081,032.29 3,997,042 4,296,956 12,600,283 41.99 300,078 2009 7,384,717.84 1,944,692 2,090,610 6,771,051 42.93 157,723 2010 5,983,748.42 1,453,046 1,562,074 5,618,424 43.87 128,070 2011 7,759,232.10 1,725,064 1,854,503 7,456,576 44.81 166,404 2012 4,107,062.34 827,097 889,157 4,039,318 45.77 88,253 2013 12,342,603.08 2,229,815 2,397,127 12,413,997 46.72 265,711 2014 14,457,892.82 2,305,918 2,478,941 14,870,530 47.69 311,817 2015 9,004,453.96 1,247,477 1,341,080 9,464,265 48.65 194,538 2016 22,412,915.86 2,630,918 2,828,327 24,067,172 49.62 485,030 2017 25,067,332.45 2,411,878 2,592,851 27,487,948 50.59 543,347 2018 15,171,467.68 1,135,311 1,220,498 16,985,263 51.57 329,363 2019 13,987,594.60 750,798 807,134 15,977,980 52.54 304,111 2020 9,893,107.51 319,468 343,439 11,528,290 53.52 215,402 2021 9,974,273.13 106,645 114,647 11,854,481 54.51 217,474 269,917,387.93 72,747,067 78,205,577 245,695,289 5,693,794 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 43.2 2.11 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-275 Attachment C J. Spanos, Avista Page 755 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 378.00 MEASURING AND REGULATING EQUIPMENT - GENERAL CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 32-R2 NET SALVAGE PERCENT.. -15 1963 9,933.81 11,338 8,820 2,604 0.24 2,604 1964 923.13 1,045 813 249 0.49 249 1966 1,425.52 1,587 1,235 404 1.02 396 1968 1,591.50 1,740 1,354 476 1.57 303 1969 337.56 366 285 103 1.85 56 1971 317.24 337 262 103 2.42 43 1980 9,820.19 9,490 7,383 3,910 5.11 765 1984 4,279.02 3,920 3,050 1,871 6.51 287 1986 1.00 1 1 1989 43,137.57 36,245 28,196 21,412 8.62 2,484 1991 28,816.76 23,208 18,054 15,085 9.59 1,573 1992 8,504.94 6,694 5,208 4,573 10.10 453 1993 88,811.56 68,206 53,060 49,073 10.63 4,616 1994 14,343.92 10,732 8,349 8,147 11.18 729 1995 9,049.74 6,586 5,124 5,283 11.75 450 1996 13,759.99 9,727 7,567 8,257 12.33 670 1997 2,898.77 1,986 1,545 1,789 12.94 138 1998 92,653.72 61,400 47,765 58,787 13.56 4,335 1999 707.92 453 352 462 14.19 33 2000 95,513.11 58,868 45,796 64,044 14.85 4,313 2001 32,905.24 19,500 15,170 22,671 15.51 1,462 2002 48,588.89 27,589 21,463 34,414 16.20 2,124 2003 27,645.26 15,002 11,671 20,121 16.90 1,191 2004 75,989.24 39,297 30,571 56,817 17.61 3,226 2005 1,475.60 724 563 1,134 18.34 62 2006 470,794.13 218,596 170,054 371,359 19.08 19,463 2007 155,202.50 67,879 52,806 125,677 19.83 6,338 2008 568,884.87 233,065 181,310 472,908 20.60 22,957 2009 445,284.94 170,107 132,333 379,745 21.37 17,770 2010 689,955.61 243,986 189,806 603,643 22.16 27,240 2011 428,559.91 139,076 108,192 384,652 22.97 16,746 2012 126,665.64 37,419 29,110 116,555 23.78 4,901 2013 574,048.71 152,661 118,761 541,395 24.60 22,008 2014 447,309.82 105,453 82,036 432,370 25.44 16,996 2015 39,865.11 8,195 6,375 39,470 26.28 1,502 2016 181,777.38 31,750 24,699 184,345 27.14 6,792 2017 518,550.67 74,542 57,989 538,344 28.00 19,227 2018 435,175.22 48,794 37,959 462,493 28.88 16,014 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-276 Attachment C J. Spanos, Avista Page 756 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 378.00 MEASURING AND REGULATING EQUIPMENT - GENERAL CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 32-R2 NET SALVAGE PERCENT.. -15 2019 62,361.95 5,020 3,905 67,811 29.76 2,279 2020 60,898.26 2,955 2,299 67,734 30.65 2,210 2021 298,270.93 4,823 3,752 339,260 31.55 10,753 6,117,036.85 1,960,362 1,525,043 5,509,549 245,758 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 22.4 4.02 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-277 Attachment C J. Spanos, Avista Page 757 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 379.00 MEASURING AND REGULATING EQUIPMENT - CITY GATE CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 37-S0.5 NET SALVAGE PERCENT.. -15 1956 1,149.55 1,217 1,071 251 2.94 85 1963 12,120.81 11,946 10,516 3,423 5.29 647 1964 1.00 1 1 1966 6,195.92 5,910 5,203 1,922 6.31 305 1970 369.61 336 296 129 7.71 17 1977 833.57 692 609 350 10.28 34 1978 475.08 389 342 204 10.67 19 1980 8,118.61 6,447 5,675 3,661 11.45 320 1986 7,485.15 5,365 4,723 3,885 13.94 279 1991 5,480.56 3,543 3,119 3,184 16.20 197 1992 9,168.83 5,791 5,098 5,446 16.68 326 1994 59,397.89 35,704 31,431 36,877 17.66 2,088 1997 2,205.95 1,220 1,074 1,463 19.21 76 1998 87,203.31 46,754 41,158 59,126 19.75 2,994 2001 80,103.16 38,740 34,103 58,016 21.44 2,706 2004 45,229.95 19,330 17,017 34,997 23.25 1,505 2005 4,007.30 1,634 1,438 3,170 23.88 133 2006 42,163.71 16,355 14,398 34,090 24.52 1,390 2007 445,441.39 163,646 144,060 368,198 25.18 14,623 2008 103,589.92 35,867 31,574 87,554 25.86 3,386 2010 201,258.09 60,864 53,580 177,867 27.27 6,522 2011 2,618.57 732 644 2,367 28.01 85 2012 7,644.17 1,958 1,724 7,067 28.76 246 2014 176,742.55 36,695 32,303 170,951 30.32 5,638 2015 475,503.33 86,754 76,371 470,458 31.13 15,113 2016 76,250.03 11,921 10,494 77,194 31.97 2,415 2017 147,440.85 19,109 16,822 152,735 32.83 4,652 2018 104,527.98 10,689 9,410 110,797 33.71 3,287 2019 508,393.21 37,763 33,243 551,409 34.61 15,932 2020 425,367.61 19,171 16,877 472,296 35.55 13,285 2021 303,508.35 4,621 4,068 344,967 36.51 9,449 3,349,996.01 691,164 608,442 3,244,054 107,754 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 30.1 3.22 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-278 Attachment C J. Spanos, Avista Page 758 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 380.00 SERVICES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 52-R3 NET SALVAGE PERCENT.. -25 1971 50,257.69 49,267 61,728 1,094 11.22 98 1972 309,527.82 299,708 375,512 11,398 11.72 973 1973 277,620.60 265,273 332,367 14,659 12.25 1,197 1974 253,241.03 238,692 299,063 17,488 12.79 1,367 1975 169,777.52 157,738 197,634 14,588 13.35 1,093 1976 196,630.73 179,947 225,460 20,328 13.93 1,459 1977 220,437.09 198,606 248,838 26,708 14.52 1,839 1978 245,598.50 217,674 272,729 34,269 15.13 2,265 1979 127,894.01 111,415 139,595 20,273 15.76 1,286 1980 291,653.17 249,589 312,716 51,850 16.40 3,162 1981 233,129.85 195,806 245,330 46,082 17.06 2,701 1982 266,380.84 219,445 274,948 58,028 17.73 3,273 1983 197,107.39 159,154 199,408 46,976 18.41 2,552 1984 447,708.00 353,969 443,497 116,138 19.11 6,077 1985 547,405.08 423,452 530,553 153,703 19.82 7,755 1986 772,726.67 584,191 731,947 233,961 20.55 11,385 1987 1,105,140.92 816,105 1,022,518 358,908 21.28 16,866 1988 1,244,966.36 896,920 1,123,773 432,435 22.03 19,629 1989 1,454,656.76 1,021,405 1,279,744 538,577 22.79 23,632 1990 1,574,644.22 1,076,506 1,348,781 619,524 23.56 26,296 1991 1,660,201.30 1,103,868 1,383,064 692,188 24.34 28,438 1992 2,010,356.57 1,298,514 1,626,940 886,006 25.13 35,257 1993 2,526,476.25 1,583,311 1,983,770 1,174,325 25.93 45,288 1994 2,740,316.74 1,663,955 2,084,810 1,340,586 26.74 50,134 1995 2,615,694.51 1,536,721 1,925,396 1,344,222 27.56 48,774 1996 2,865,226.72 1,626,159 2,037,455 1,544,078 28.39 54,388 1997 2,809,936.20 1,538,019 1,927,022 1,585,398 29.23 54,239 1998 2,511,889.28 1,323,577 1,658,342 1,481,520 30.08 49,253 1999 2,661,627.89 1,348,081 1,689,044 1,637,991 30.93 52,958 2000 2,676,674.54 1,299,726 1,628,459 1,717,384 31.80 54,006 2001 2,081,076.73 966,998 1,211,576 1,389,770 32.67 42,540 2002 2,324,505.01 1,030,395 1,291,007 1,614,624 33.56 48,112 2003 2,644,621.32 1,115,700 1,397,888 1,907,889 34.45 55,381 2004 2,739,063.51 1,096,276 1,373,551 2,050,278 35.35 57,999 2005 1,661,530.55 629,055 788,159 1,288,754 36.25 35,552 2006 2,589,995.49 923,916 1,157,597 2,079,897 37.16 55,971 2007 2,050,585.55 686,152 859,697 1,703,535 38.08 44,736 2008 1,187,980.96 370,962 464,787 1,020,189 39.01 26,152 2009 1,741,379.18 504,826 632,509 1,544,215 39.94 38,663 2010 822,891.98 219,969 275,605 753,010 40.88 18,420 2011 2,518,520.11 615,715 771,445 2,376,705 41.83 56,818 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-279 Attachment C J. Spanos, Avista Page 759 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 380.00 SERVICES CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 52-R3 NET SALVAGE PERCENT.. -25 2012 614,881.32 136,281 170,750 597,852 42.78 13,975 2013 2,754,150.93 547,525 686,008 2,756,681 43.73 63,039 2014 13,517,168.61 2,375,304 2,976,077 13,920,384 44.69 311,488 2015 8,510,381.47 1,299,110 1,627,687 9,010,290 45.65 197,378 2016 6,468,475.16 836,536 1,048,116 7,037,478 46.62 150,954 2017 6,501,342.30 689,224 863,546 7,263,132 47.59 152,619 2018 12,692,003.79 1,046,456 1,311,130 14,553,875 48.57 299,647 2019 7,838,887.27 463,572 580,821 9,217,788 49.54 186,068 2020 7,527,159.13 267,779 335,507 9,073,442 50.52 179,601 2021 6,398,500.41 75,342 94,398 7,903,728 51.51 153,441 130,250,005.03 37,933,886 47,528,304 115,284,202 2,796,194 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 41.2 2.15 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-280 Attachment C J. Spanos, Avista Page 760 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 381.00 METERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 35-R1 NET SALVAGE PERCENT.. -3 1960 1,122.73 1,062 722 434 2.85 152 1961 562.32 527 358 221 3.15 70 1962 2,835.24 2,632 1,790 1,130 3.45 328 1963 8,568.39 7,880 5,359 3,466 3.75 924 1964 17,764.04 16,175 11,000 7,297 4.06 1,797 1965 20,488.62 18,468 12,560 8,543 4.37 1,955 1966 21,564.33 19,235 13,081 9,130 4.69 1,947 1967 7,278.62 6,422 4,367 3,130 5.02 624 1968 18,104.97 15,798 10,744 7,904 5.35 1,477 1969 5,472.51 4,720 3,210 2,427 5.69 427 1971 30,838.69 25,974 17,664 14,100 6.38 2,210 1972 74,855.18 62,254 42,337 34,764 6.74 5,158 1973 60,811.69 49,912 33,944 28,692 7.11 4,035 1974 68,202.61 55,236 37,564 32,685 7.48 4,370 1975 47,255.28 37,742 25,667 23,006 7.86 2,927 1976 1,136.47 895 609 562 8.25 68 1977 28,092.14 21,784 14,815 14,120 8.65 1,632 1978 6,990.55 5,336 3,629 3,571 9.06 394 1979 61,497.42 46,204 31,422 31,920 9.47 3,371 1980 162,588.67 120,145 81,707 85,759 9.89 8,671 1981 1,986.03 1,442 981 1,065 10.32 103 1982 1,015.36 724 492 554 10.76 51 1983 207,478.88 145,256 98,784 114,919 11.21 10,251 1984 278,539.17 191,236 130,054 156,841 11.67 13,440 1985 16,838.69 11,328 7,704 9,640 12.14 794 1986 360,575.85 237,584 161,574 209,819 12.61 16,639 1987 72,190.53 46,525 31,640 42,716 13.10 3,261 1988 144,567.44 91,086 61,945 86,959 13.59 6,399 1989 250,600.68 154,133 104,821 153,298 14.10 10,872 1990 301,422.27 180,868 123,003 187,462 14.61 12,831 1991 406,047.39 237,316 161,392 256,837 15.14 16,964 1992 760,715.92 432,513 294,139 489,398 15.68 31,212 1993 637,996.04 352,599 239,792 417,344 16.22 25,730 1994 932,306.42 499,891 339,961 620,315 16.78 36,968 1995 1,147,041.42 596,126 405,408 776,045 17.34 44,755 1996 948,217.14 476,612 324,130 652,534 17.92 36,414 1997 1,204,129.91 584,693 397,633 842,621 18.50 45,547 1998 1,372,713.80 642,318 436,822 977,073 19.10 51,156 1999 770,231.01 346,800 235,848 557,490 19.70 28,299 2000 1,049,743.72 453,806 308,620 772,616 20.31 38,041 2001 98,094.95 40,617 27,622 73,416 20.93 3,508 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-281 Attachment C J. Spanos, Avista Page 761 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 381.00 METERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 35-R1 NET SALVAGE PERCENT.. -3 2002 1,147,307.72 453,783 308,605 873,122 21.56 40,497 2003 1,357,828.40 511,469 347,835 1,050,728 22.20 47,330 2004 3,886,265.74 1,390,711 945,782 3,057,072 22.84 133,847 2005 18,264.64 6,181 4,204 14,609 23.50 622 2006 600,921.98 191,874 130,488 488,462 24.15 20,226 2007 998,642.34 299,179 203,463 825,139 24.82 33,245 2008 863,804.05 241,745 164,404 725,314 25.49 28,455 2009 1,977,342.52 514,400 349,828 1,686,835 26.16 64,481 2010 1,486,512.00 356,962 242,759 1,288,348 26.84 48,001 2011 3,245,596.57 714,425 485,859 2,857,105 27.52 103,819 2012 2,102,504.53 420,122 285,713 1,879,867 28.21 66,638 2013 5,292,144.24 950,039 646,093 4,804,816 28.90 166,257 2014 214,236.92 34,046 23,154 197,510 29.60 6,673 2015 1,226,281.95 169,618 115,352 1,147,718 30.30 37,878 2016 28,313.26 3,325 2,261 26,902 31.01 868 2017 781,938.90 75,474 51,328 754,069 31.72 23,773 2018 445,494.24 33,561 22,824 436,035 32.44 13,441 2019 9,066,601.35 490,930 333,867 9,004,732 33.16 271,554 2020 4,999,846.46 163,301 111,056 5,038,786 33.89 148,681 2021 4,485,739.75 48,837 33,213 4,587,099 34.63 132,460 55,834,070.65 13,311,856 9,053,002 48,456,091 1,864,518 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 26.0 3.34 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-282 Attachment C J. Spanos, Avista Page 762 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 385.00 INDUSTRIAL MEASURING AND REGULATING STATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-R2.5 NET SALVAGE PERCENT.. -15 1964 19,421.01 15,686 22,334 1965 9,262.49 7,389 10,652 1966 17,369.29 13,681 19,975 1967 4,182.18 3,251 4,810 1968 5,029.87 3,856 5,784 1969 3,512.89 2,655 4,040 1970 10,615.92 7,907 12,208 1971 14,048.30 10,307 16,156 1972 4,414.90 3,189 5,019 58 24.17 2 1973 3,401.23 2,418 3,806 105 24.82 4 1974 5,698.23 3,984 6,271 282 25.48 11 1975 15.30 11 17 1 26.16 1976 14,993.20 10,123 15,933 1,309 26.84 49 1977 588.85 390 614 63 27.53 2 1978 8,031.00 5,226 8,226 1,010 28.22 36 1979 21,609.05 13,790 21,705 3,145 28.93 109 1980 46,935.13 29,363 46,217 7,758 29.64 262 1981 68,595.29 42,027 66,150 12,735 30.37 419 1982 5,544.76 3,326 5,235 1,141 31.10 37 1983 7,737.42 4,539 7,144 1,754 31.84 55 1984 4,026.98 2,309 3,634 997 32.59 31 1985 14,235.55 7,974 12,551 3,820 33.34 115 1986 11,640.26 6,364 10,017 3,369 34.10 99 1987 2,073.32 1,105 1,739 645 34.87 18 1988 13,024.24 6,763 10,645 4,333 35.65 122 1991 2,727.11 1,302 2,049 1,087 38.02 29 1992 30,120.16 13,946 21,951 12,687 38.83 327 1993 17,927.89 8,044 12,661 7,956 39.64 201 1994 10,626.05 4,614 7,262 4,958 40.46 123 1995 8,289.92 3,479 5,476 4,057 41.28 98 1996 7,983.09 3,233 5,089 4,092 42.11 97 1998 6,757.56 2,536 3,992 3,779 43.79 86 1999 1,738.79 626 985 1,015 44.64 23 2000 34,798.09 12,005 18,896 21,122 45.50 464 2001 62,472.19 20,602 32,427 39,416 46.36 850 2002 59,494.71 18,715 29,457 38,962 47.22 825 2003 66,431.18 19,863 31,264 45,132 48.10 938 2004 86,071.33 24,411 38,423 60,559 48.97 1,237 2005 4,746.81 1,272 2,002 3,457 49.85 69 2006 35,068.57 8,847 13,925 26,404 50.74 520 2007 7,238.66 1,712 2,695 5,629 51.63 109 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-283 Attachment C J. Spanos, Avista Page 763 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 385.00 INDUSTRIAL MEASURING AND REGULATING STATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-R2.5 NET SALVAGE PERCENT.. -15 2008 98,147.23 21,654 34,083 78,786 52.53 1,500 2009 240,597.87 49,250 77,519 199,169 53.43 3,728 2010 95,854.16 18,095 28,481 81,751 54.33 1,505 2011 5,472.78 945 1,487 4,807 55.24 87 2012 53,854.16 8,432 13,272 48,660 56.15 867 2013 162,020.89 22,732 35,780 150,544 57.07 2,638 2014 162,381.18 20,140 31,700 155,038 57.99 2,674 2015 272,383.41 29,348 46,193 267,048 58.91 4,533 2016 142,118.46 12,974 20,421 143,015 59.84 2,390 2017 35,106.22 2,627 4,135 36,237 60.77 596 2018 207,566.46 12,083 19,019 219,682 61.71 3,560 2019 101,420.21 4,235 6,666 109,967 62.64 1,756 2020 64,794.64 1,628 2,562 71,952 63.58 1,132 2021 76,331.50 635 999 86,782 64.53 1,345 2,476,547.94 557,618 871,753 1,976,277 35,678 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 55.4 1.44 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-284 Attachment C J. Spanos, Avista Page 764 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 387.00 OTHER EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 18-SQUARE NET SALVAGE PERCENT.. 0 1967 173.85 174 174 1986 365.44 365 365 539.29 539 539 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 0.0 0.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-285 Attachment C J. Spanos, Avista Page 765 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 30-R3 NET SALVAGE PERCENT.. -5 1994 1,085,967.69 861,665 888,281 251,985 7.33 34,377 1995 16,329.95 12,637 13,027 4,119 7.89 522 1999 35,202.44 24,112 24,857 12,106 10.43 1,161 2000 20,153.90 13,318 13,729 7,433 11.12 668 2001 7,552.01 4,800 4,948 2,982 11.84 252 2002 2,551.00 1,555 1,603 1,076 12.58 86 2003 2,830.67 1,651 1,702 1,270 13.34 95 2004 14,048.06 7,808 8,049 6,701 14.12 475 2006 137,595.44 68,723 70,846 73,629 15.73 4,681 2007 19,721.62 9,284 9,571 11,137 16.55 673 2008 645,750.53 284,776 293,573 384,465 17.40 22,096 2009 814,895.25 334,838 345,181 510,459 18.26 27,955 2010 154,132.15 58,586 60,396 101,443 19.14 5,300 2011 26,334.08 9,189 9,473 18,178 20.03 908 2012 126,914.57 40,289 41,534 91,726 20.93 4,383 2013 162,056.95 46,227 47,655 122,505 21.85 5,607 2014 175,631.44 44,383 45,754 138,659 22.78 6,087 2015 79,042.58 17,402 17,939 65,056 23.71 2,744 2017 44,703.25 6,853 7,065 39,873 25.62 1,556 2018 118,639.84 14,201 14,640 109,932 26.58 4,136 2019 82,049.49 7,036 7,253 78,899 27.55 2,864 2020 128,202.39 6,596 6,800 127,813 28.53 4,480 2021 210,768.55 3,614 3,725 217,582 29.51 7,373 4,111,073.85 1,879,543 1,937,601 2,379,026 138,479 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 17.2 3.37 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-286 Attachment C J. Spanos, Avista Page 766 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 391.10 OFFICE FURNITURE AND EQUIPMENT - COMPUTER HARDWARE CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 5-SQUARE NET SALVAGE PERCENT.. 0 2019 12,222.51 6,111 6,111 6,112 2.50 2,445 12,222.51 6,111 6,111 6,112 2,445 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 2.5 20.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-287 Attachment C J. Spanos, Avista Page 767 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 392.20 TRANSPORTATION EQUIPMENT - LIGHT TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 14-L2.5 NET SALVAGE PERCENT.. +10 2006 690.43 419 510 111 4.55 24 2009 29,723.95 16,949 20,619 6,133 5.13 1,196 2010 62,284.30 34,514 41,987 14,069 5.38 2,615 2011 410,105.51 218,556 265,876 103,219 5.71 18,077 2013 265,618.96 125,163 152,262 86,795 6.67 13,013 2014 45,043.13 19,372 23,566 16,973 7.31 2,322 2015 697,144.61 267,555 325,484 301,946 8.03 37,602 2016 580,701.39 193,002 234,789 287,842 8.83 32,598 2017 158,526.17 43,923 53,433 89,241 9.69 9,210 2018 298,090.76 65,155 79,262 189,020 10.60 17,832 2019 175,280.57 27,719 33,721 124,032 11.54 10,748 2020 225,969.23 21,645 26,331 177,041 12.51 14,152 2021 336,592.19 10,818 13,160 289,773 13.50 21,465 3,285,771.20 1,044,790 1,271,000 1,686,194 180,854 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 9.3 5.50 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-288 Attachment C J. Spanos, Avista Page 768 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 392.30 TRANSPORTATION EQUIPMENT - MEDIUM TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 17-L2.5 NET SALVAGE PERCENT.. +10 2006 30,432.07 17,465 27,311 78 6.16 13 2008 280,525.06 153,266 239,672 12,801 6.68 1,916 2009 50,697.03 26,732 41,803 3,824 7.04 543 2011 64,553.84 30,758 48,098 10,000 8.00 1,250 2013 136,718.14 55,733 87,153 35,893 9.30 3,859 2015 182,637.54 59,175 92,536 71,838 10.88 6,603 2016 172,011.14 47,900 74,905 79,905 11.74 6,806 2019 123,539.88 16,154 25,261 85,925 14.53 5,914 2021 140,221.03 3,712 5,805 120,394 16.50 7,297 1,181,335.73 410,895 642,544 420,659 34,201 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 12.3 2.90 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-289 Attachment C J. Spanos, Avista Page 769 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 392.50 TRANSPORTATION EQUIPMENT - OTHER CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 16-L2 NET SALVAGE PERCENT.. +10 2006 13,427.33 7,288 6,465 5,620 6.35 885 2010 9,708.03 4,663 4,136 4,601 7.46 617 2013 12,863.27 5,202 4,615 6,962 8.81 790 2018 87,935.53 16,620 14,743 64,399 12.64 5,095 2019 94,180.71 12,926 11,467 73,296 13.56 5,405 2021 12,538.13 353 313 10,971 15.50 708 230,653.00 47,052 41,739 165,849 13,500 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 12.3 5.85 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-290 Attachment C J. Spanos, Avista Page 770 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 393.00 STORES EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 25-SQUARE NET SALVAGE PERCENT.. 0 1999 8,500.00 7,650 7,650 850 2.50 340 2000 8,700.00 7,482 7,482 1,218 3.50 348 2008 3,438.47 1,857 1,857 1,581 11.50 137 2018 153.35 21 21 132 21.50 6 20,791.82 17,010 17,010 3,782 831 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 4.6 4.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-291 Attachment C J. Spanos, Avista Page 771 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 394.00 TOOLS, SHOP AND GARAGE EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 20-SQUARE NET SALVAGE PERCENT.. 0 2002 42,644.55 41,578 41,319 1,326 0.50 1,326 2003 92,514.06 85,576 85,044 7,470 1.50 4,980 2005 40,869.79 33,718 33,508 7,362 3.50 2,103 2006 110,479.39 85,622 85,090 25,389 4.50 5,642 2007 181,671.02 131,711 130,892 50,779 5.50 9,233 2008 74,892.80 50,553 50,239 24,654 6.50 3,793 2009 2,115.75 1,322 1,314 802 7.50 107 2011 8,099.70 4,252 4,226 3,874 9.50 408 2012 34,048.04 16,173 16,072 17,976 10.50 1,712 2014 125,607.39 47,103 46,810 78,797 12.50 6,304 2018 19,059.66 3,335 3,314 15,746 16.50 954 2019 18,772.77 2,347 2,332 16,441 17.50 939 2020 142,458.29 10,684 10,618 131,840 18.50 7,126 2021 69,538.83 1,738 1,727 67,812 19.50 3,478 962,772.04 515,712 512,505 450,267 48,105 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 9.4 5.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-292 Attachment C J. Spanos, Avista Page 772 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 395.00 LABORATORY EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2019 18,586.31 3,098 3,104 15,483 12.50 1,239 18,586.31 3,098 3,104 15,483 1,239 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 12.5 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-293 Attachment C J. Spanos, Avista Page 773 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 396.50 POWER OPERATED EQUIPMENT - OTHER CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 16-S0 NET SALVAGE PERCENT.. 0 1994 5,315.22 4,760 5,315 2006 38,518.73 22,654 39,063 544 - 43,833.95 27,414 44,378 544 - COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 0.0 0.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-294 Attachment C J. Spanos, Avista Page 774 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 397.00 COMMUNICATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2007 2,293.81 2,217 2,216 78 0.50 78 2008 12,447.75 11,203 11,195 1,253 1.50 835 2009 30,623.99 25,520 25,503 5,121 2.50 2,048 2010 206,229.31 158,110 158,003 48,226 3.50 13,779 2011 225,434.95 157,804 157,698 67,737 4.50 15,053 2012 22,167.55 14,039 14,029 8,139 5.50 1,480 2014 8,574.78 4,287 4,284 4,291 7.50 572 2015 1,756.37 761 760 996 8.50 117 2016 28,335.13 10,390 10,383 17,952 9.50 1,890 2018 27,203.88 6,347 6,343 20,861 11.50 1,814 2019 111,985.35 18,665 18,653 93,332 12.50 7,467 2020 89,344.02 8,934 8,928 80,416 13.50 5,957 766,396.89 418,277 417,995 348,402 51,090 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 6.8 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-295 Attachment C J. Spanos, Avista Page 775 of 800 AVISTA CORPORATION GAS PLANT - OREGON ACCOUNT 398.00 MISCELLANEOUS EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 FULLY ACCRUED NET SALVAGE PERCENT.. 0 2010 2,367.16 2,367 2,367 2,367.16 2,367 2,367 AMORTIZED SURVIVOR CURVE.. 10-SQUARE NET SALVAGE PERCENT.. 0 2021 6,732.60 337 338 6,395 9.50 673 6,732.60 337 338 6,395 673 9,099.76 2,704 2,705 6,395 673 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 9.5 7.40 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-296 Attachment C J. Spanos, Avista Page 776 of 800 COMMON PLANT _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-297 Attachment C J. Spanos, Avista Page 777 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 389.30 REMOVING PROPERTY OF OTHERS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-R4 NET SALVAGE PERCENT.. 0 1908 1,023.98 1,024 1,024 1914 14.47 14 14 1918 65.20 65 65 1922 376.04 376 376 1924 301.36 299 168 133 0.44 133 1926 431.58 426 239 193 0.77 193 1929 0.13 1930 52.70 51 29 24 1.59 15 1937 19.14 18 10 9 3.26 3 1951 3,652.86 3,243 1,821 1,832 7.29 251 1967 19,339.06 14,677 8,241 11,098 15.67 708 2008 23,758.96 4,916 2,760 20,999 51.55 407 2009 1,685,653.07 323,123 181,423 1,504,230 52.54 28,630 2017 1,888,643.45 130,467 73,253 1,815,391 60.51 30,002 3,623,332.00 478,699 269,423 3,353,909 60,342 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 55.6 1.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-298 Attachment C J. Spanos, Avista Page 778 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 389.40 LAND EASEMENTS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 65-R4 NET SALVAGE PERCENT.. 0 1906 55.00 55 55 1907 300.00 300 300 1908 6,750.54 6,751 6,751 1910 678.56 679 679 1913 6,930.46 6,930 6,930 1914 885.27 885 885 1922 1,373.34 1,373 1,373 1925 25.00 25 25 1926 110.15 109 110 1927 2,403.14 2,368 2,403 1928 767.07 753 767 1930 904.30 882 904 1935 201.00 192 201 1936 162.66 155 163 1937 206.73 196 207 1940 264.20 248 264 1942 49.88 46 49 1 4.57 1943 103.41 96 102 1 4.85 1944 564.12 520 555 9 5.12 2 1949 1,367.59 1,229 1,311 57 6.61 9 1951 44.04 39 42 2 7.29 1952 75.00 66 70 5 7.65 1 1954 79.96 70 75 5 8.42 1 1972 813.02 573 611 202 19.20 11 1975 1,775.45 1,189 1,268 507 21.46 24 1982 12,896.86 7,516 8,014 4,883 27.12 180 2019 99,328.41 3,820 4,074 95,255 62.50 1,524 139,115.16 37,065 38,188 100,928 1,752 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 57.6 1.26 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-299 Attachment C J. Spanos, Avista Page 779 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 50-R2 NET SALVAGE PERCENT.. -10 1924 137.47 151 151 1933 75,259.99 80,915 43,004 39,782 1.13 35,205 1937 1,689.89 1,777 944 915 2.20 416 1938 92.45 97 52 50 2.48 20 1940 25.93 27 14 15 3.04 5 1943 460.10 467 248 258 3.91 66 1947 326.02 322 171 188 5.07 37 1949 581.30 567 301 338 5.65 60 1954 918.45 866 460 550 7.15 77 1956 956.19 888 472 580 7.78 75 1957 103,854.39 95,733 50,879 63,361 8.10 7,822 1958 282.24 258 137 173 8.43 21 1959 12,745.89 11,561 6,144 7,876 8.77 898 1962 204.00 180 96 128 9.83 13 1963 1,677.64 1,469 781 1,064 10.21 104 1964 88.66 77 41 57 10.59 5 1967 32,605.47 27,394 14,559 21,307 11.81 1,804 1969 206.61 170 90 137 12.68 11 1970 1,717.31 1,393 740 1,149 13.13 88 1972 7,668.67 6,062 3,222 5,214 14.07 371 1974 535,343.23 411,508 218,704 370,174 15.06 24,580 1975 8,929.63 6,764 3,595 6,228 15.57 400 1976 270,984.77 202,160 107,442 190,641 16.09 11,848 1978 39,157.70 28,282 15,031 28,042 17.17 1,633 1979 248,643.18 176,522 93,816 179,691 17.73 10,135 1980 2,038.90 1,422 756 1,487 18.30 81 1981 19,743.21 13,517 7,184 14,534 18.88 770 1982 101,810.42 68,360 36,331 75,660 19.48 3,884 1983 37,879.94 24,934 13,252 28,416 20.08 1,415 1984 58,829.15 37,921 20,154 44,558 20.70 2,153 1985 322,123.02 203,247 108,020 246,315 21.32 11,553 1986 74,562.00 45,996 24,446 57,572 21.96 2,622 1987 841,672.43 507,360 269,647 656,193 22.60 29,035 1988 65,506.24 38,536 20,481 51,576 23.26 2,217 1989 206,820.53 118,620 63,043 164,460 23.93 6,873 1990 355,735.93 198,785 105,648 285,662 24.60 11,612 1991 166,359.80 90,437 48,065 134,931 25.29 5,335 1992 384,202.56 203,028 107,903 314,720 25.98 12,114 1993 1,845,236.30 946,274 502,917 1,526,843 26.69 57,207 1994 259,051.00 128,800 68,453 216,503 27.40 7,902 1995 130,939.89 63,000 33,483 110,551 28.13 3,930 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-300 Attachment C J. Spanos, Avista Page 780 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 390.10 STRUCTURES AND IMPROVEMENTS - COMPANY CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 50-R2 NET SALVAGE PERCENT.. -10 1996 236,676.26 110,073 58,501 201,843 28.86 6,994 1997 406,842.56 182,591 97,042 350,485 29.60 11,841 1998 1,432,690.77 619,352 329,167 1,246,793 30.35 41,080 1999 732,340.77 304,507 161,836 643,739 31.10 20,699 2000 1,981,376.95 790,292 420,017 1,759,498 31.87 55,209 2001 809,946.00 309,335 164,402 726,539 32.64 22,259 2002 205,715.82 75,037 39,880 186,407 33.42 5,578 2003 651,149.07 226,196 120,216 596,048 34.21 17,423 2004 650,833.24 214,632 114,071 601,846 35.01 17,191 2006 5,230,160.54 1,539,550 818,225 4,934,952 36.62 134,761 2007 2,753,910.31 760,960 404,428 2,624,873 37.44 70,109 2008 7,031,123.92 1,815,999 965,150 6,769,086 38.26 176,923 2009 7,875,950.08 1,890,386 1,004,684 7,658,861 39.09 195,929 2010 7,671,424.36 1,699,527 903,248 7,535,319 39.93 188,713 2011 13,487,082.75 2,738,687 1,455,531 13,380,260 40.77 328,189 2012 10,965,997.88 2,019,279 1,073,187 10,989,411 41.63 263,978 2013 16,676,105.12 2,758,895 1,466,271 16,877,445 42.48 397,303 2014 5,340,430.68 781,305 415,241 5,459,233 43.35 125,934 2015 15,620,914.39 1,986,355 1,055,689 16,127,317 44.22 364,706 2016 8,221,481.44 888,084 471,990 8,571,640 45.09 190,101 2017 3,290,784.56 291,761 155,062 3,464,801 45.97 75,371 2018 15,510,460.21 1,071,463 569,451 16,492,055 46.86 351,943 2019 21,633,465.04 1,070,857 569,129 23,227,683 47.75 486,444 2020 3,172,828.66 94,233 50,083 3,440,029 48.65 70,710 2021 1,517,725.93 15,025 7,985 1,661,514 49.55 33,532 159,324,485.81 28,000,228 14,881,363 160,375,571 3,907,317 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 41.0 2.45 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-301 Attachment C J. Spanos, Avista Page 781 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 391.00 OFFICE FURNITURE AND EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2007 256,717.89 248,161 246,942 9,776 0.50 9,776 2008 337,192.39 303,473 301,983 35,209 1.50 23,473 2009 730,268.77 608,555 605,566 124,703 2.50 49,881 2010 940,273.98 720,880 717,339 222,935 3.50 63,696 2011 259,501.40 181,651 180,759 78,742 4.50 17,498 2012 2,657,068.50 1,682,801 1,674,536 982,532 5.50 178,642 2013 960,770.97 544,440 541,766 419,005 6.50 64,462 2014 777,791.46 388,896 386,986 390,805 7.50 52,107 2015 1,498,940.88 649,536 646,346 852,595 8.50 100,305 2016 5,079,937.37 1,862,661 1,853,512 3,226,425 9.50 339,624 2017 2,220,387.60 666,116 662,844 1,557,544 10.50 148,338 2018 812,992.31 189,695 188,764 624,228 11.50 54,281 2019 472,970.29 78,830 78,443 394,527 12.50 31,562 2020 937,145.48 93,715 93,254 843,891 13.50 62,510 2021 633,194.75 21,104 21,001 612,194 14.50 42,220 18,575,154.04 8,240,514 8,200,041 10,375,113 1,238,375 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 8.4 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-302 Attachment C J. Spanos, Avista Page 782 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 391.10 OFFICE FURNITURE AND EQUIPMENT - COMPUTER HARDWARE CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 FULLY ACCRUED NET SALVAGE PERCENT.. 0 2012 279,566.69 279,567 279,567 2014 211,804.08 211,804 211,804 491,370.77 491,371 491,371 AMORTIZED SURVIVOR CURVE.. 5-SQUARE NET SALVAGE PERCENT.. 0 2017 13,948,925.32 12,554,033 11,793,596 2,155,330 0.50 2,155,330 2018 12,524,852.91 8,767,397 8,236,328 4,288,525 1.50 2,859,017 2019 18,305,587.61 9,152,794 8,598,380 9,707,207 2.50 3,882,883 2020 9,759,495.74 2,927,849 2,750,500 7,008,996 3.50 2,002,570 2021 6,399,601.65 639,960 601,196 5,798,406 4.50 1,288,535 60,938,463.23 34,042,033 31,980,000 28,958,463 12,188,335 61,429,834.00 34,533,404 32,471,371 28,958,463 12,188,335 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 2.4 19.84 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-303 Attachment C J. Spanos, Avista Page 783 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 391.12 OFFICE FURNITURE AND EQUIPMENT - COMPUTER HARDWARE - AMI CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 5-SQUARE NET SALVAGE PERCENT.. 0 2018 4,425,214.49 3,097,650 3,097,650 1,327,564 1.50 885,043 2019 538,384.25 269,192 269,192 269,192 2.50 107,677 4,963,598.74 3,366,842 3,366,842 1,596,757 992,720 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 1.6 20.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-304 Attachment C J. Spanos, Avista Page 784 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 391.13 OFFICE FURNITURE AND EQUIPMENT - COMPUTER HARDWARE - MDM CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 5-SQUARE NET SALVAGE PERCENT.. 0 2017 2,637,348.63 2,373,614 2,110,000 527,349 0.50 527,349 2,637,348.63 2,373,614 2,110,000 527,349 527,349 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 1.0 20.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-305 Attachment C J. Spanos, Avista Page 785 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 392.10 TRANSPORTATION EQUIPMENT - AUTOS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 11-S2.5 NET SALVAGE PERCENT.. +10 2017 41,871.94 15,040 37,685 2020 42,867.97 5,261 87,272 48,691 - 84,739.91 20,301 124,957 48,691 - COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 0.0 0.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-306 Attachment C J. Spanos, Avista Page 786 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 392.20 TRANSPORTATION EQUIPMENT - LIGHT TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 14-L2.5 NET SALVAGE PERCENT.. +10 1998 16,650.05 12,031 14,985 2001 90,955.75 61,980 81,860 2003 2,942.83 1,915 2,649 2006 97,978.37 59,522 88,181 2008 16,755.25 9,780 15,080 2009 148,641.04 84,757 133,777 2010 358,481.88 198,649 322,634 2011 162,768.49 86,744 146,492 2012 281,196.39 142,085 253,077 2013 786,058.26 370,401 707,452 2014 465,025.84 199,996 408,310 10,213 7.31 1,397 2015 362,269.38 139,034 283,850 42,192 8.03 5,254 2016 379,910.00 126,267 257,786 84,133 8.83 9,528 2017 354,741.71 98,290 200,668 118,600 9.69 12,239 2018 172,051.50 37,606 76,776 78,070 10.60 7,365 2019 284,720.28 45,025 91,923 164,325 11.54 14,240 2020 380,542.40 36,451 74,418 268,070 12.51 21,428 2021 229,361.83 7,371 15,048 191,378 13.50 14,176 4,591,051.25 1,717,904 3,174,966 956,980 85,627 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 11.2 1.87 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-307 Attachment C J. Spanos, Avista Page 787 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 392.30 TRANSPORTATION EQUIPMENT - MEDIUM TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 17-L2.5 NET SALVAGE PERCENT.. +10 2000 8,592.99 5,486 7,734 2006 116,501.39 66,858 104,851 2009 59,345.33 31,292 53,411 2010 83,203.39 41,935 74,883 2012 506,162.73 224,826 455,546 2014 268,332.85 98,590 207,943 33,557 10.06 3,336 2016 29,303.04 8,160 17,211 9,162 11.74 780 2017 61,375.64 14,167 29,881 25,357 12.64 2,006 2018 128,029.26 23,248 49,034 66,192 13.57 4,878 2019 134,994.38 17,652 37,231 84,264 14.53 5,799 2020 184,739.40 14,573 30,736 135,529 15.51 8,738 1,580,580.40 546,787 1,068,461 354,061 25,537 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 13.9 1.62 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-308 Attachment C J. Spanos, Avista Page 788 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 392.40 TRANSPORTATION EQUIPMENT - HEAVY TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 20-R4 NET SALVAGE PERCENT.. +10 2010 120,321.54 60,101 16,007 92,282 8.90 10,369 2019 306,044.75 34,430 9,170 266,270 17.50 15,215 426,366.29 94,531 25,177 358,552 25,584 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 14.0 6.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-309 Attachment C J. Spanos, Avista Page 789 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 392.50 TRANSPORTATION EQUIPMENT - OTHER CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 16-L2 NET SALVAGE PERCENT.. +10 1971 1,227.50 1,105 1,105 1979 7,170.14 6,223 6,453 1980 23,661.61 20,324 21,295 1981 1,319.36 1,120 1,187 1982 12,384.93 10,394 11,146 1984 9,647.63 7,901 8,683 1985 29,525.51 23,882 26,573 1988 17,030.72 13,239 15,328 1990 7,136.83 5,387 6,423 1992 382.24 280 344 1993 33,842.88 24,348 30,459 1994 2,000.00 1,414 1,800 1995 2,217.04 1,539 1,995 1996 1,573.39 1,072 1,416 1997 4,162.13 2,779 3,746 1999 10,868.08 6,957 9,781 2002 4,370.47 2,611 3,933 2006 69,135.25 37,527 62,222 2008 15,781.45 8,123 14,203 2009 5,031.64 2,508 4,528 2010 49,283.20 23,674 44,355 2012 91,472.81 39,671 82,326 2013 35,349.35 14,297 29,985 1,829 8.81 208 2014 37,056.96 13,695 28,722 4,629 9.43 491 2015 101,257.45 33,377 70,001 21,131 10.14 2,084 2017 68,593.75 16,360 34,311 27,423 11.76 2,332 2018 339,245.35 64,117 134,471 170,850 12.64 13,517 2019 27,121.55 3,722 7,806 16,603 13.56 1,224 2020 69,199.45 5,799 12,162 50,118 14.51 3,454 2021 38,802.38 1,091 2,288 32,634 15.50 2,105 1,115,851.05 394,536 679,047 325,219 25,415 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 12.8 2.28 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-310 Attachment C J. Spanos, Avista Page 790 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 392.60 TRANSPORTATION EQUIPMENT - AIRPLANE CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 12-S1.5 NET SALVAGE PERCENT.. +30 2017 369,037.76 89,983 258,326 2018 6,197,768.05 1,203,916 3,566,044 772,394 8.67 89,088 6,566,805.81 1,293,899 3,824,370 772,394 89,088 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 8.7 1.36 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-311 Attachment C J. Spanos, Avista Page 791 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 393.00 STORES EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 25-SQUARE NET SALVAGE PERCENT.. 0 1997 3,205.58 3,141 3,141 65 0.50 65 1998 60,655.10 57,016 57,010 3,645 1.50 2,430 1999 45,928.15 41,335 41,331 4,597 2.50 1,839 2000 1,664.83 1,432 1,432 233 3.50 67 2002 10,804.60 8,428 8,427 2,378 5.50 432 2003 28,759.23 21,282 21,280 7,479 6.50 1,151 2004 32,776.00 22,943 22,941 9,835 7.50 1,311 2005 61,940.42 40,881 40,877 21,063 8.50 2,478 2006 3,843.34 2,383 2,383 1,460 9.50 154 2007 7,145.39 4,144 4,144 3,001 10.50 286 2008 90,577.25 48,912 48,907 41,670 11.50 3,623 2009 329,970.49 164,985 164,967 165,003 12.50 13,200 2010 304,038.18 139,858 139,843 164,195 13.50 12,163 2011 312,295.71 131,164 131,150 181,146 14.50 12,493 2012 122,946.25 46,720 46,715 76,231 15.50 4,918 2014 1,107,667.58 332,300 332,265 775,403 17.50 44,309 2015 750,536.62 195,140 195,119 555,418 18.50 30,023 2018 1,026,662.49 143,733 143,718 882,944 21.50 41,067 2019 476,621.26 47,662 47,657 428,964 22.50 19,065 2020 190,105.17 11,406 11,405 178,700 23.50 7,604 2021 374,243.86 7,485 7,484 366,760 24.50 14,970 5,342,387.50 1,472,350 1,472,196 3,870,192 213,648 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 18.1 4.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-312 Attachment C J. Spanos, Avista Page 792 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 394.00 TOOLS, SHOP AND GARAGE EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 20-SQUARE NET SALVAGE PERCENT.. 0 2002 3,841.74 3,746 3,747 95 0.50 95 2003 30,344.18 28,068 28,074 2,270 1.50 1,513 2004 42,743.60 37,401 37,409 5,335 2.50 2,134 2005 198,190.69 163,507 163,541 34,650 3.50 9,900 2006 296,486.65 229,777 229,825 66,662 4.50 14,814 2007 372,625.57 270,154 270,211 102,415 5.50 18,621 2008 573,874.49 387,365 387,447 186,427 6.50 28,681 2009 1,095,420.00 684,638 684,782 410,638 7.50 54,752 2010 1,625,577.68 934,707 934,904 690,674 8.50 81,256 2011 1,165,626.99 611,954 612,083 553,544 9.50 58,268 2012 2,070,887.36 983,671 983,878 1,087,009 10.50 103,525 2014 3,005,839.69 1,127,190 1,127,427 1,878,413 12.50 150,273 2015 1,952,192.52 634,463 634,596 1,317,597 13.50 97,600 2016 4,314.88 1,187 1,187 3,128 14.50 216 2017 21,623.18 4,865 4,866 16,757 15.50 1,081 2018 1,348,256.50 235,945 235,995 1,112,262 16.50 67,410 2019 686,866.44 85,858 85,876 600,990 17.50 34,342 2020 120,473.34 9,036 9,038 111,435 18.50 6,024 2021 2,273,977.94 56,849 56,861 2,217,117 19.50 113,698 16,889,163.44 6,490,381 6,491,747 10,397,417 844,203 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 12.3 5.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-313 Attachment C J. Spanos, Avista Page 793 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 395.00 LABORATORY EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2007 17,920.97 17,324 17,262 659 0.50 659 2008 164,618.88 148,157 147,627 16,992 1.50 11,328 2009 70,497.51 58,748 58,538 11,960 2.50 4,784 2018 911,816.91 212,754 211,993 699,824 11.50 60,854 2019 301,035.10 50,174 49,994 251,041 12.50 20,083 2020 41,901.57 4,190 4,175 37,726 13.50 2,795 1,507,790.94 491,347 489,589 1,018,202 100,503 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 10.1 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-314 Attachment C J. Spanos, Avista Page 794 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 396.30 POWER OPERATED EQUIPMENT - MEDIUM TRUCKS CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 16-L2 NET SALVAGE PERCENT.. 0 1995 59,501.89 45,891 59,502 59,501.89 45,891 59,502 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 0.0 0.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-315 Attachment C J. Spanos, Avista Page 795 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 396.50 POWER OPERATED EQUIPMENT - OTHER CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. IOWA 16-S0 NET SALVAGE PERCENT.. 0 1958 3,503.28 3,503 3,503 1980 10,587.37 10,587 10,587 1981 26,435.30 26,435 26,435 1982 10,427.41 10,427 10,427 1984 45,392.01 45,392 45,392 1985 10,913.78 10,914 10,914 1986 36,367.74 36,368 36,368 1994 30,323.12 27,158 30,323 1995 57,695.72 50,304 57,696 1996 56,442.55 47,835 56,443 1997 947.00 780 947 1999 12,070.69 9,340 11,794 277 3.62 77 2000 51,974.17 38,916 49,140 2,834 4.02 705 2001 551,387.79 398,720 503,470 47,918 4.43 10,817 2007 119,111.71 66,703 84,227 34,885 7.04 4,955 2008 304,623.18 161,639 204,104 100,519 7.51 13,385 2009 67,934.94 34,010 42,945 24,990 7.99 3,128 2010 43,821.86 20,596 26,007 17,815 8.48 2,101 2011 142,158.36 62,282 78,644 63,514 8.99 7,065 2014 100,010.96 33,692 42,543 57,468 10.61 5,416 2018 60,491.72 10,813 13,654 46,838 13.14 3,565 2019 142,750.60 19,003 23,995 118,756 13.87 8,562 2020 8,388.90 703 888 7,501 14.66 512 2021 36,926.39 1,108 1,399 35,527 15.52 2,289 1,930,686.55 1,127,228 1,371,845 558,842 62,577 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 8.9 3.24 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-316 Attachment C J. Spanos, Avista Page 796 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 397.00 COMMUNICATION EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2007 460,183.71 444,846 443,780 16,404 0.50 16,404 2008 3,834,434.88 3,450,991 3,442,718 391,717 1.50 261,145 2009 997,063.17 830,883 828,891 168,172 2.50 67,269 2010 1,247,391.71 956,338 954,045 293,347 3.50 83,813 2011 860,440.48 602,308 600,864 259,576 4.50 57,684 2012 17,760,630.90 11,248,340 11,221,373 6,539,258 5.50 1,188,956 2013 566,591.69 321,071 320,301 246,291 6.50 37,891 2014 2,299,849.05 1,149,925 1,147,168 1,152,681 7.50 153,691 2015 3,488,662.10 1,511,742 1,508,118 1,980,544 8.50 233,005 2016 11,677,920.85 4,281,943 4,271,677 7,406,244 9.50 779,605 2017 7,960,917.54 2,388,275 2,382,550 5,578,368 10.50 531,273 2018 7,093,925.27 1,655,226 1,651,258 5,442,667 11.50 473,275 2019 9,091,677.07 1,515,310 1,511,677 7,580,000 12.50 606,400 2020 11,803,617.89 1,180,362 1,177,532 10,626,086 13.50 787,117 2021 14,261,565.90 475,338 474,198 13,787,368 14.50 950,853 93,404,872.21 32,012,898 31,936,150 61,468,722 6,228,381 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 9.9 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-317 Attachment C J. Spanos, Avista Page 797 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 397.12 COMMUNICATION EQUIPMENT - AMI CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 15-SQUARE NET SALVAGE PERCENT.. 0 2018 6,909,282.92 1,612,143 1,608,107 5,301,176 11.50 460,972 2020 37,188.64 3,719 3,710 33,479 13.50 2,480 2021 584,040.54 19,466 19,417 564,623 14.50 38,940 7,530,512.10 1,635,328 1,631,234 5,899,278 502,392 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 11.7 6.67 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-318 Attachment C J. Spanos, Avista Page 798 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 397.20 COMMUNICATION EQUIPMENT - PORTABLE CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 10-SQUARE NET SALVAGE PERCENT.. 0 2012 1,666,734.57 1,583,398 1,506,932 159,803 0.50 159,803 2015 22,397.29 14,558 13,855 8,542 3.50 2,441 2016 746,353.99 410,495 390,671 355,683 4.50 79,041 2018 620,616.92 217,216 206,726 413,891 6.50 63,676 2019 165,228.02 41,307 39,312 125,916 7.50 16,789 2020 292,720.71 43,908 41,788 250,933 8.50 29,522 2021 2,871.60 144 137 2,735 9.50 288 3,516,923.10 2,311,026 2,199,421 1,317,502 351,560 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 3.7 10.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-319 Attachment C J. Spanos, Avista Page 799 of 800 AVISTA CORPORATION COMMON PLANT ACCOUNT 398.00 MISCELLANEOUS EQUIPMENT CALCULATED REMAINING LIFE DEPRECIATION ACCRUAL RELATED TO ORIGINAL COST AS OF DECEMBER 31, 2021 SURVIVOR CURVE.. 10-SQUARE NET SALVAGE PERCENT.. 0 2013 67,265.29 57,175 57,173 10,092 1.50 6,728 2014 336,388.45 252,291 252,284 84,104 2.50 33,642 2015 11,216.06 7,290 7,290 3,926 3.50 1,122 2016 6,500.26 3,575 3,575 2,925 4.50 650 2017 4,567.50 2,055 2,055 2,512 5.50 457 2018 134,870.22 47,205 47,203 87,667 6.50 13,487 2019 122,248.74 30,562 30,561 91,688 7.50 12,225 2020 8,927.12 1,339 1,339 7,588 8.50 893 2021 15,398.14 770 770 14,628 9.50 1,540 707,381.78 402,262 402,250 305,132 70,744 COMPOSITE REMAINING LIFE AND ANNUAL ACCRUAL RATE, PERCENT .. 4.3 10.00 _____________________________________________________________________________________________ Avista Corporation December 31, 2021IX-320 Attachment C J. Spanos, Avista Page 800 of 800