20260731Application.pdf

1,
Avista Corp.
1411 East Mission P.O. Box 3727 RECEIVED
Spokane, Washington 99220-0500 JULY 31, 2026
Telephone [phone] IDAHO PUBLIC
Toll Free 800-727-9170 UTILITIES COMMISSION
July 31, 2026
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-26-03
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-Sixth Revision Sheet 150 canceling Thirty-Fifth Revision Sheet 150
Twenty-Eighth Revision Sheet 155 canceling Twenty- Seventh Revision Sheet 155
The Company requests that the proposed tariff sheets be made effective November 1, 2026. These tariff sheets
reflect the Company's annual Purchased Gas Cost Adjustment ("PGA"). If approved, the Company's annual
revenue will decrease by approximately $2.5 million or approximately 3.0%. 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 $58.56 to $56.96, a decrease of$1.60 per month, or approximately
2.7%. The proposed natural gas rate changes would be effective November 1,2026.
If you have any questions regarding this filing,please contact Marcus Garbarino at(509)495-2567.
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 )
A CHANGE IN RATES FOR PURCHASED GAS ) CASE: AVU-G-26-03
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 1,2026. If approved as filed,the Company's annual revenue will
decrease by approximately $2.5 million or 3.0%. 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(d),avistacorp.com
Dockets kavistacorp.com
11.
Attorney for the Applicant and her address is as follows:
Anni Glogovac
Counsel, Legal Department
Avista Utilities
1411 E. Mission Avenue
P.O. Box 3727, MSC 33
Spokane, WA 99220-3727
Phone: [phone]
anni._lg_o og vac(a�avistacorp.com
Case No. AVU-G-26-03 Page t of 5

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-Sixth Revision Sheet 150, which Applicant requests the Commission approve, is filed herewith
as Exhibit "A". Additionally, Twenty-Eighth 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-Sixth Revision Sheet 150 and Twenty-Eighth Revision Tariff Sheet 155 with the changes
underlined and a copy of Thirty-Fifth Revision Sheet 150 and Twenty-Seventh 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 2026 through October 2027 (Schedule 150),and 2)revise
Case No.AVU-G-26-03 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 the per the Change per the per the
General 101 $ (0.04529) $ 0.00995 $ (0.03534) $ 0.01113 $ (0.02421)
Lg. General ill $ (0.04529) $ 0.00995 $ (0.03534) $ 0.01113 $ (0.02421)
Lg General 112 $ (0.04529) $ 0.00995 $ (0.03534) $ - $ (0.03534)
Interruptible 131 $ (0.04529) $ - $ (0.04529) $ - $ (0.04529)
Transportation 146 $ - $ - $ - $ - $ -
IX.
Schedule 150/Purchase Gas Cost- Commodity Costs
As shown in the table above, the estimated WACOG change is a decrease of$0.04529 per therm; the
proposed WACOG of $0.16619 per therm compared to the present WACOG of $0.21148 per therm
included in rates. The decrease is a result of current forward prices being lower as compared to when the
Company filed its PGA in the prior year.
Natural gas commodity prices this past year, in the Pacific Northwest, were generally lower as winter
loads came in lighter than forecast as temperatures remained elevated, which ultimately reduced
customer demand. As a result, the region exited winter with healthy storage supplies that have carried
over to this spring. The region's largest supply points, Sumas and AECO, have continued to trade at a
discount to Henry Hub, the national natural gas benchmark. Supply has been plentiful to meet demand
for the region and pipeline flows have been uninhibited for much of the typical maintenance season. A
fundamental change to the region is the addition of LNG Canada. This liquefied natural gas (LNG)
facility located near the coast of British Columbia is a new source of demand for the region.With offtake
nearing 2 Bcf/day, LNG Canada has contributed to an elevated price floor for daily pricing at AECO.
As such, pricing has not dipped as low as we have seen in spring and summer periods in past years and
could signal a material change in regional market dynamics.
Looking toward the upcoming winter of 2026-2027, national fundamentals look balanced as production
has remained stable, LNG offtake has increased as expected, and storage is currently at levels slightly
above the 5-year rolling average. Conflicts in the Middle East have created some volatility in gas
markets, but that has largely been relegated to the international LNG markets and not national prices, as
LNG output is already maximized within the United States. Regionally, storage is above the 5-year
rolling range for the West, and with pipeline flows having been generally uninhibited, we have seen a
convergence of winter strip (November—March)pricing in the Pacific Northwest. Currently the region
is on a healthy, well-supplied path towards the winter season ahead.
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 34% of the annual load
requirements for this year's PGA period(November 2026 through October 2027)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$2.61 per dekatherm($0.26065 per therm).
Case No.AVU-G-26-03 Page 3 of 5

Available underground storage capacity at the Jackson Prairie Natural Gas Storage Facility represents
approximately 20% of annual load requirements (27% of load requirements during the November to
March withdrawal period). The estimated WACOG for all storage volumes is $1.15 per dekatherm
($0.1147 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, 2026) to
develop an estimated cost associated with index purchases. These index purchases represent
approximately 46% of estimated annual load requirements for the coming year. The annual weighted
average price for these volumes is $1.87 per dekatherm ($0.1874 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 $0.00995 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 Change
As shown in the table above, the proposed amortization rate change for Schedule 101 and Schedule I I I
is an increase in revenue of $0.01113 per therm. The current rate applicable to Schedule 101 and
Schedule 11 I is $0.06278 per therm in the rebate direction; the proposed rate is $0.05165 per therm in
the rebate direction.
In this PGA filing, the Company has used the deferral and amortization balances as of June 30, 2026,
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, 2026 through October 31,
2026 being collected through Schedule 155,which increased the balance to be collected in the upcoming
PGA year by approximately$1.0 million. The result is an amortization rate to rebate approximately$5.2
million to customers. On a per therm basis, the net impact of the expiring amortization rebate and the
new amortization rebate is a change in the amortization rate of$0.01113 per therm.
XII.
If this Application and associated tariffs are approved as filed, the Company's annual revenue will
decrease by approximately $2.5 million or 3.0% effective November 1, 2026. Residential or small
commercial customers using an average of 66 therms per month would see a decrease of$1.60 per month,
or approximately 2.7%. The present bill for 66 therms is $58.56 while the proposed bill is $56.96.
Case No.AVU-G-26-03 Page 4 of 5

XIII.
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,
2026, 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 fair,just,
reasonable, and nondiscriminatory, and to become effective for all natural gas service on and after
November 1,2026. The overall decrease is approximately$2.5 million or 3.0%. 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 2026.
AVISTA UTILITIES
BY
/s/ Patrick D. Ehrbar
Patrick D. Ehrbar
Director of Regulatory Affairs
Avista Corporation
Case No.AVU-G-26-03 Page 5 of 5