20250731Application.pdf

' 11
Avista Corp.
1411 East Mission P.O. Box 3727 RECEIVED
Spokane, Washington 99220-0500 JULY 31, 2025
Telephone [phone] IDAHO PUBLIC
Toll Free 800-727-9170 UTILITIES COMMISSION
July 31, 2025
Commission Secretary
State of Idaho
Idaho Public Utilities Commission
11331 W. Chinden Blvd. Building 8, Suite 201-A
Boise, Idaho 83714
Case No. AVU-G-25-07
I.P.U.C.No. 27—Natural Gas Service
The Company has attached for electronic filing with the Commission are the following revised tariff sheets:
Thirty-Fifth Revision Sheet 150 canceling Thirty-Fourth Revision Sheet 150
Twenty-Seventh Revision Sheet 155 canceling Twenty-Sixth Revision Sheet 155
The Company requests that the proposed tariff sheets be made effective November 1, 2025. These tariff sheets
reflect the Company's annual Purchased Gas Cost Adjustment ("PGA"). If approved, the Company's annual
revenue will decrease by approximately $6.5 million or approximately 7.2%. The proposed changes have no
effect on the Company's earnings.Detailed information related to the Company's request was filed electronically
along with the attached Application and supporting workpapers.
If the PGA filing is approved,residential natural gas customers in Idaho using an average of 66 therms per month
would see their monthly bills decrease from $64.74 to $60.61, a decrease of$4.13 per month, or approximately
6.4%. The proposed natural gas rate changes would be effective November 1, 2025.
If you have any questions regarding this filing,please contact Derek Isaak at(509)495-7326.
Sincerely,
/s/Patrick D. Ehrbar
Patrick D. Ehrbar
Director of Regulatory Affairs

BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF THE APPLICATION OF )
AVISTA UTILITIES FOR AN ORDER APPROVING ) CASE: AVU-G-25-07
A CHANGE IN RATES FOR PURCHASED GAS )
COSTS AND AMORTIZATION OF GAS-RELATED )
DEFERRAL BALANCES )
This application ("Application") is hereby made to the Idaho Public Utilities Commission for an Order
approving a revised schedule of rates and charges for natural gas service in the state of Idaho. The
Applicant requests that the proposed rates included in this Purchased Gas Cost Adjustment ("PGA")
filing be made effective on November 1, 2025. If approved as filed,the Company's annual revenue will
decrease by approximately $6.5 million or about 7.2%. In support of this Application, Applicant states
as follows:
I.
The name of the Applicant is AVISTA CORPORATION, doing business as AVISTA UTILITIES
(hereinafter"Avista","Applicant"or"Company"), a Washington corporation,whose principal business
office is 1411 East Mission Avenue, Spokane, Washington, and is qualified to do business in the state
of Idaho. Applicant maintains district offices in Moscow, Lewiston, Coeur d'Alene, Sandpoint, and
Kellogg, Idaho. Communications in reference to this Application should be addressed to:
Patrick D. Ehrbar
Director of Regulatory Affairs
Avista Utilities
1411 E. Mission Avenue
Spokane, WA 99220-3727
Phone: [phone]
Pat.ehrbar(ab avi stacorp.com
Dockets kavistacorp.com
II.
Attorney for the Applicant and his address is as follows:
David J. Meyer
Vice President and Chief Counsel for Regulatory
And Governmental Affairs
Avista Utilities
1411 E. Mission Avenue
Spokane, WA 99220-3727
Phone: [phone]
Case No.AVU-G-25-05 Page 1 of 5

David.meyergavistacorp.com
III.
The Applicant is a public utility engaged in the distribution of natural gas in certain portions of Northern
Idaho, Eastern and Central Washington, and Southwestern and Northeastern Oregon, and further
engaged in the generation, transmission, and distribution of electricity in Northern Idaho and Eastern
Washington.
IV.
Thirty-Fifth Revision Sheet 150, which Applicant requests the Commission approve, is filed herewith
as Exhibit "A". Additionally, Twenty-Seventh Revision Sheet 155, which Applicant requests the
Commission approve, is also filed herewith as Exhibit "A". Also included in Exhibit "A" is a copy of
Thirty-Fifth Revision Sheet 150 and Twenty-Seventh Revision Tariff Sheet 155 with the changes
underlined and a copy of Thirty-Fourth Revision Sheet 150 and Twenty-Sixth Revision Tariff Sheet 155
with the proposed changes shown by lining over the current language or rates.
V.
The existing rates and charges for natural gas service on file with the Commission and designated as
Applicant's Tariff IPUC No. 27, which will be superseded by the rates and charges filed herewith, are
incorporated herein as though fully attached hereto.
VI.
Notice to the Public of Applicant's proposed tariffs is to be given simultaneously with the filing of this
Application by posting, at each of the Company's district offices in Idaho, a Notice in the form attached
hereto as Exhibit "B" and by means of a press release distributed to various informational agencies, a
draft copy attached hereto in Exhibit"C". In addition, Exhibit"C" to this Application also contains the
form of customer notice that the Company will send to its customers in its monthly bills in the August
timeframe.
VII.
The circumstances and conditions relied on for approval of Applicant's revised rates are as follows:
Applicant purchases natural gas for customer usage and transports it over Williams Northwest Pipeline,
Gas Transmission Northwest ("GTN"), TC Energy - Alberta, TC Energy - BC, and Enbridge Energy
Pipeline systems, and defers the effect of timing differences due to implementation of rate changes and
differences between Applicant's actual weighted average cost of gas ("WACOG") purchased and the
WACOG embedded in rates. Applicant also defers various pipeline refunds or charges and
miscellaneous revenue received from natural gas related transactions including pipeline capacity
releases. Workpapers for all proposed Commodity, Demand and Amortization costs are provided with
this filing as Exhibit"D".
VIII.
This filing reflects the Company's proposed annual PGA to: 1) pass through changes in the estimated
cost of natural gas for the period of November 2025 through October 2026(Schedule 150),and 2)revise
Case No.AVU-G-25-05 Page 2 of 5

the amortization rate(s) to refund or collect the balance of deferred natural gas costs (Schedule 155).
Below is a table summarizing the proposed rate changes reflected in this filing:
Commodity Demand Total Amortization Total PGA
Sch. Change Change Sch. 150 Change Rate Change
Service No. per therm per therm Chance per the per therm
General 101 $ (0.02702) $ 0.00985 $ (0.01717) $ (0.04544) $ (0.06261)
Lg. General 111 $ (0.02702) $ 0.00985 $ (0.01717) $ (0.04544) $ (0.06261)
Lg General 112 $ (0.02702) $ 0.00985 $ (0.01717) $ - $ (0.01717)
Interruptible 131 $ (0.02702) $ - $ (0.02702) $ - $ (0.02702)
Transportation 146 $ - $ - $ - $ - $ -
IX.
Schedule 150/Purchase Gas Cost- Commodity Costs
As shown in the table above, the estimated WACOG change is a decrease of$0.02702 per therm; the
proposed WACOG of $0.21148 per therm compared to the present WACOG of$0.23850 per therm
included in rates. The decrease is a result of current forward prices being lower compared to when the
Company filed its PGA in the prior year.
The past year has been relatively uneventful for the natural gas market in the Pacific Northwest. While
the Central and Eastern United States had seen a couple of large demand events in January and February,
those events did not extend to our region. The region's largest supply points, Sumas and AECO, have
traded at a discount to Henry Hub, the national natural gas benchmark, since the end of this last winter
as supply has been plentiful to meet demand for the region aside from some interstate pipeline
maintenance. Before the winter season had ended, Sumas was trading much more closely to Henry Hub;
AECO however maintained its consistent, historical discount throughout the past year.
As we look toward the upcoming winter, the national market fundamentals show strong production that
is matched by growth in demand for LNG feed-gas that is exported abroad. Currently, the national gas
storage volume has exceeded the five-year average for this time of year and some bearish price signals
have appeared as supply confidence grows in strength. That bearishness has been even stronger for the
Pacific Northwest as storage balances are near the top of the five-year range and Canadian production
remains strong (which provides most of the supply to the Pacific Northwest region). One new source of
demand in Western Canada is LNG Canada, located in British Columbia. LNG Canada, when fully
operational (projected by end of 2025), will provide the region with additional demand of nearly 2
Bcf/day. Despite this incremental demand, recent pricing for the upcoming winter has fallen, displaying
the market's perception of supply strength for the region and its ability to serve demand.
Avista has been hedging natural gas on both a periodic and discretionary basis throughout the previous
thirty-six (36) months for the forthcoming PGA year. Approximately 50% of the annual load
requirements for this year's PGA period(November 2025 through October 2026)have been hedged at a
fixed price derived from the Company's plan. Through June, the hedge volumes for the PGA period
have been executed at a weighted average price of$2.73 per dekatherm($0.27331 per therm).
Available underground storage capacity at the Jackson Prairie Natural Gas Storage Facility represents
approximately 17% of annual load requirements (23% of load requirements during the November to
Case No.AVU-G-25-05 Page 3 of 5

March withdrawal period). The estimated WACOG for all storage volumes is $1.10 per dekatherm
($0.1102 per therm). The Company utilizes its underground storage to capture seasonal price spreads
(differentials), improve the reliability of supply, increase operational flexibility and mitigate peak
demand price spikes.
The Company used a 30-day historical average of AECO forward prices (ending June 30, 2025) to
develop an estimated cost associated with index purchases. These index purchases represent
approximately 33% of estimated annual load requirements for the coming year. The annual weighted
average price for these volumes is $2.58 per dekatherm ($0.2584 per therm).
X.
Schedule 150/Purchase Gas Cost-Demand Costs
Demand costs reflect the cost of pipeline transportation to the Company's system, as well as fixed costs
associated with natural gas storage. As shown in the table above, demand costs are expected to increase
for residential customers by approximately $0.00985 per therm. This increase is related to a variety of
factors including Canadian exchange rate, updated demand forecast, and new pipeline rates in effect
during the upcoming PGA year.
XI.
Schedule 155/Amortization Rate Chance
As shown in the table above,the proposed amortization rate change for Schedule 101 and Schedule I I I
is a decrease in revenue of$0.04544 per therm. The current rate applicable to Schedule 101 and Schedule
I I I is $0.01734 per therm in the rebate direction; the proposed rate is $0.06278 per therm in the rebate
direction.
In this PGA filing, the Company has used the deferral and amortization balances as of June 30, 2025,
inclusive of the residual amortization balance from the prior PGA, and proposed amortizing the balance
over twelve (12) months which is consistent with historical PGA filings. The Company included
forecasted amortization of the prior year rebate deferral balance from July 1, 2025 through October 31,
2025 being collected through Schedule 155,which increased the balance to be collected in the upcoming
PGA year by approximately$0.2 million. The result is a rebate amortization rate to collect approximately
$6.5 million from customers. On a per therm basis,the net impact of the expiring amortization surcharge
and the new amortization rebate is a change in the amortization rate of$0.04544 per therm.
XII.
If approved as filed,the Company's annual revenue will decrease by approximately$6.5 million or 7.2%
effective November 1, 2025. Residential or small commercial customers using an average of 66 therms
per month would see a decrease of$4.13 per month, or approximately 6.4%. The present bill for 66
therms is $64.74 while the proposed bill is $60.61.
XIII.
Case No.AVU-G-25-05 Page 4 of 5

Exhibit "D" attached hereto contains support workpapers for the Proposed Tariff Rates proposed by
Applicant contained in Exhibit "A".
XIV.
Avista requests that the rates proposed in this filing be approved to become effective on November 1,
2025, and requests that the matter be processed under the Commission's Modified Procedure rules
through the use of written comments. Avista stands ready for immediate consideration on this
Application.
XV.
WHEREFORE, Avista requests the Commission issue its Order finding its proposed rates to be just,
reasonable, and nondiscriminatory and to become effective for all natural gas service on and after
November 1,2025. The overall decrease is approximately$6.5 million or 7.2%. The Company requests
that the matter be processed under the Commission's Modified Procedure rules through the use of written
comments.
Dated at Spokane, Washington, this 31st day of July 2025.
AVISTA UTILITIES
BY
/s/ Patrick D. Ehrbar
Patrick D. Ehrbar
Director of Regulatory Affairs
Avista Corporation
Case No.AVU-G-25-05 Page 5 of 5

DAVID J. MEYER
VICE PRESIDENT AND CHIEF COUNSEL FOR
REGULATORY&GOVERNMENTAL AFFAIRS
AVISTA CORPORATION
P.O. BOX 3727
1411 EAST MISSION AVENUE
SPOKANE,WASHINGTON 99220-3727
TELEPHONE: [phone]
FACSIMILE: [phone]
[e-mail]
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF THE APPLICATION ) CASE NO. AVU-G-25-07
OF AVISTA CORPORATION FOR AN )
ORDER APPROVING A CHANGE ) ATTORNEY'S CERTIFICATE
IN NATURAL GAS RATES AND CHARGES ) CLAIM OF CONFIDENTIALITY
TO NATURAL GAS CUSTOMERS IN THE ) RELATING TO PORTIONS
STATE OF IDAHO ) OF AVISTA'S EXHIBIT'S
AND WORKPAPERS

1 FOR AVISTA CORPORATION
2 I,David J.Meyer,represent Avista Corporation. I am Vice President and Chief Counsel
3 for Regulatory and Governmental Affairs for Avista Corporation(Avista or Company)and I am
4 appearing on its behalf in this proceeding.
5 I make this certification and claim of confidentiality pursuant to IDAPA 31.01.01
6 because Avista, through its supporting workpapers, is disclosing certain information that is
7 CONFIDENTIAL and constitutes TRADE SECRETS as defined by Idaho Code Section 9-340
8 and 48-801 and protected under IDAPA 31.01.01.067 and 31.01.01.233.
9 The electronic information Avista provides will, as required under IDAPA Rule
10 31.01.01.067,be marked as CONFIDENTIAL on all documents.
11 The confidential information that Avista is disclosing includes, but is not limited to
12 certain forward wholesale natural gas pricing which is provided by a third-party vendor, who
13 does not allow public access to their proprietary information. Avista herein asserts that the
14 aforementioned information is confidential in that making third-party pricing data public will
15 violate the terms of our agreement with the vendor.
16 I am of the opinion that this information is CONFIDENTIAL,as defined by Idaho Code
17 Sections 9-340D and 48-801, should therefore be protected from public inspection, examination
18 and copying, and should be utilized only in accordance with the terms of the protective
19 agreement between Avista Corporation and Parties who have requested such an agreement.
20 RESPECTFULLY SUBMITTED this 31 st day of July 2025
21 Is/David J. Meyer
22 David J. Meyer
23 Vice President and Chief Counsel for
24 Regulatory&Governmental Affairs
25 Avista Corporation
26
ATTORNEY'S CERTIFICATE - 1