20260709APPLICATION.pdf

11
RECEIVED
July 09, 2026
Avista Corp. IDAHO PUBLIC
1411 East Mission Ave., P.O. Box 3727 UTIL iTiFS COMMISGinN
Spokane, WA 99220-0500 AVU-E-26-10
Telephone: [phone]
Toll Free: 800-227-9187
July 9, 2025
Commission Secretary
Idaho Public Utilities Commission
11331 W. Chinden Blvd
Building 8, Suite 201-A
Boise, ID 83714
Re: Case No. AVU-E-26- - Application of Avista Corporation for a Certificate of Public
Convenience and Necessity for Carlin Bay Transmission Line
Commission Secretary:
Avista Corporation, doing business as Avista Utilities (Avista or the Company), hereby submits
for filing with the Commission an application for a Certificate of Public Convenience and
Necessity for the development of the Carlin Bay transmission line. If you have any questions
regarding this filing, please contact me at(509)495-2782 or shawn.bonfield(&,avistacorp.com.
Sincerely,
l al s" FacZ�zc&
Shawn Bonfield
Sr. Manager of Regulatory Policy& Strategy

I ANNIGLOGOVAC
2 ISB #13010
3 COUNSEL, LEGAL DEPARTMENT
4 AVISTA CORPORATION
5 P.O. BOX 3727, MSC 33
6 1411 EAST MISSION AVENUE
7 SPOKANE, WASHINGTON 99220-3727
8 TELEPHONE: [phone]
9 EMAIL: [e-mail]
10
11
12 BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
13
14 IN THE MATTER OF THE APPLICATION ) CASE NO. AVU-E-26-
15 OF AVISTA CORPORATION FOR )
16 A CERTIFICATE OF PUBLIC CONVENIENCE ) APPLICATION FOR A
17 AND NECESSITY TO CONSTRUCT THE ) CERTIFICATE OF PUBLIC
18 CARLIN BAY TRANSMISSION LINE ) CONVENIENCE AND
19 ) NECESSITY
20
21 I. INTRODUCTION
22 Avista Corporation,doing business as Avista Utilities(hereinafter Avista or Company),
23 at 1411 East Mission Avenue, Spokane, Washington, pursuant to Section 61-524 Idaho Code
24 and Rule of Procedure(RP) 52 of the Idaho Public Utilities Commission,respectfully requests
25 that the Commission issue an order granting the Company a Certificate of Public Convenience
26 and Necessity (CPCN) to construct a new overhead 115 kilovolt (kV) transmission line and
27 related facilities to provide service by connecting the proposed O'Gara Substation to the Carlin
28 Bay Substation.
29 The Company requests, pursuant to Idaho Code §§ 61-508 and 61-526, that the
30 Commission find it to be in the public convenience and necessity that Avista construct a new
31 115 kV transmission line as an additional source of energy for the east side of Lake Coeur
32 d'Alene. The east side of Lake Coeur d'Alene is currently supplied by two feeder lines that
33 have experienced sustained outage line events,which Avista forecasts to increase in frequency.
Application of Avista Corporation Page 1
Case Nos. AVU-E-26-

I The proposed facilities, as described herein, are necessary and required in order to continue to
2 provide: 1) reliable and adequate electricity to Avista's customers on the east side of Lake
3 Coeur d'Alene into the future, 2) increased flexibility to deliver energy and reserve capacity,
4 3) a back-up resource to shift electrical loads when there is an outage or equipment failure,
5 which will help restore power quickly, and 4) the capacity to respond to future grown and
6 energy demands.
7 Avista is a utility that provides service to approximately 419,000 electric customers
8 and 381,000 natural gas customers in a 26,000 square-mile area in northern Idaho, eastern
9 Washington, and Oregon. The largest community served by Avista is Spokane, Washington,
10 which is the location of its corporate headquarters. Communications in reference to this
11 Application should be addressed to:
12 Anni Glogovac Patrick D. Ehrbar
13 Counsel, Legal Department Director of Regulatory Affairs
14 Avista Corporation Avista Corporation
15 P.O. Box 3727 P.O. Box 3727
16 1411 E. Mission Avenue, MSC-33 1411 E. Mission Avenue, MSC-27
17 Spokane, WA 99220-3727 Spokane, WA 99220-3727
18 Phone: [phone] Phone: [phone]
19 anni.glogovac(&avistacorp.com patrick.ehrbar(a)avistacorp.com
20
21
22 Avista Dockets (Electronic Only) -AvistaDocketsgavistacom.com
23
24 II. BACKGROUND
25 The population and load demand growth on the east side of Lake Coeur d'Alene has
26 resulted in rising concerns for Avista to reliably support new customers at the far-reaching end
27 of two distribution feeders. Currently, two distribution feeders serve the east side of Lake
28 Coeur d'Alene, one originating from the Blue Creek Substation and the other originates from
29 the existing O'Gara Substation. See Illustration No. 1 below for a map of the existing feeders
Application of Avista Corporation Page 2
Case Nos. AVU-E-26-

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I The associated feeders cannot support additional growth in the area and have reached their
2 capacity. A reliable protection system requires a balance of dependability and security.
3 Dependability dictates that a protective device correctly identifies and operates in the event of
4 a faulted condition. Security ensures a protective device only operates within its defined zone
5 of protection while maintaining coordination with other protective devices located in its
6 immediate proximity.Distribution of electrical load across the electric grid and the topography
7 of each device's zone of protection have a major impact on a protective system's ability to
8 reliably operate. The existing protection system and associated protective devices in the area
9 of the proposed Carlin Bay and O'Gara substations currently meet the reliability requirements
10 outlined above;however,due to recent significant load growth,the margin for proper operation
11 is diminishing.
12 The consequence of protection coordination issues is customers will experience
13 outages due to fault detection devices, fuses and reclosers, tripping under heavy load
14 conditions. Equipment capacity issues have emerged, including overloaded feeder cable,
15 voltage drop, voltage imbalance, reduced fault current, overloaded fusing and feeder
16 protection, and cold load pickup, all of which contribute to system protection challenges (see
17 Appendix A). Construction of the Carlin Bay and O'Gara substations helps to mitigate the risk
18 of mis-operation and ensure reliable operation of the protection system by beneficially
19 modifying zones of protection and redistributing load.The addition of the proposed substations
20 has a significantly positive impact on both the dependability and security of the protection
21 system in the area. If the improvements are not made to the system,Avista will seek to prevent
22 overloading equipment by disrupting service to customers to reduce loading or risk the
23 equipment becoming damaged resulting in a longer outage duration to customers.
24 A new overhead 115 kV transmission line, which is 13 miles in length, needs to be
Application of Avista Corporation Page 4
Case Nos. AVU-E-26-

I constructed to serve the new Carlin Bay Substation. See Illustration No. 2 below for a map of
2 where the proposed new line will be.
3 Illustration No. 2 -Map of New Transmission Line
4
5
Carlin Bay Substation
7 Carlin -
O'Gara
Transmission,--l-ine
8
9
on
Blue
10Lake
4
Ande on
1 1 ! 5 � 1"f Swan
Lake
Y:
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12 4 J.
13
14
15 r '
16
17 t. :;�� • � a
18
19 This will alleviate system protection issues caused by the growing load at the end of the Blue
20 Creek and O'Gara feeders (See Appendix A).
21
22 III. COMMUNITY OUTREACH AND PUBLIC PARTICIPATION
23 Avista has conducted extensive outreach to the community, affected landowners, and
24 local jurisdictions throughout the development of the project. Once a 90%line siting route was
Application of Avista Corporation Page 5
Case Nos. AVU-E-26-

I identified,Avista and its consultant,Black&Veatch,invited the community to an Open House
2 on September 27, 2023, at Harrison Elementary School. At this event, Avista presented the
3 proposed routing, distributed fact sheets and informational materials, and held a question and
4 answer and public comment session to address community questions (See Appendix Q. All
5 comments received were documented in a feedback log, allowing Avista to follow up directly
6 with property owners after the event. A sign-in sheet was also provided to collect contact
7 information for continued engagement and discussion of any additional concerns.
8 To supplement in person outreach, Avista also developed a public facing project
9 website early in the process.' The site included detailed maps, project background, schedule
10 information, and frequently asked questions (FAQs). It also featured a project specific email
11 address,giving community members a direct channel to contact the project team with questions
12 or concerns at any time.This resource remained active throughout the routing process to ensure
13 transparency and consistent communication.
14 Following the open house, Avista worked one on one with individual property owners
15 directly impacted by the proposed route. While Avista and Black & Veatch identified which
16 parcels the line would intersect,we collaborated closely with landowners to determine the least
17 impactful alignment across each property, making adjustments wherever feasible to
18 incorporate their feedback.
19 Avista has also coordinated closely with local jurisdictions and state/federal agencies,
20 including Kootenai County, Idaho Department of Lands, Idaho Fish and Game, U.S. Fish and
21 Wildlife Service, and the Bureau of Land Management. These agencies have been engaged
22 throughout the process, and we have secured the necessary permits or easements from the
'https://www.myavista.com/about-us/construction-services/current-major-electrical-projects/carlin-bU-ogara-
transmission-line
Application of Avista Corporation Page 6
Case Nos. AVU-E-26-

I participating state and federal agencies. Coordination with Kootenai County is ongoing, and
2 they continue to participate in discussions related to the project.
3
4 IV. CERTIFICATE OF PUBLIC CONVENIENCE AND NECESSITY
5 Avista must construct additional facilities on the east side of Lake Coeur d'Alene, so it
6 can continue meeting its obligation to serve both new and existing customers. This proposed
7 new transmission line is a cost-effective way to meet this obligation. Avista is facing rising
8 concerns about reliably supporting new and existing customers on the east side of Lake Coeur
9 d'Alene. Population and load growth continue to expand. This area is currently only served by
10 two distribution feeders one originating from the Blue Creek Substation and the other
11 originates from the existing O'Gara Substation. These feeders are at capacity and unable to
12 serve new growth.
13 Avista is aware of many developments in the area that are under various stages of
14 construction or planned for in the near future. Based on current performance of the existing
15 feeders in the area, some customers are waiting for Avista to mitigate the performance issues
16 prior to beginning constructions on their developments. Table No. 1 below demonstrates the
17 expected feeder and transformer loading over the next 10 years.
18 Table No. 1. Potential Developments on the East Side of Lake Coeur d'Alene
19 Feeder
20 Powderhorn Ranch [25%conf]up to 1300 residences 2023 OGA611
Patriot Homes [100%conf]—40 units 2023 BLU321
21 Fish Inn Campground 1100% conf]Campground w/cabins& 2023 BLU321
RV spots
Burma Rd [100%conf]old mill needs cleanup 2024 BLU321
22 Gotham Bay [100%conf]—50 premium lots 2024 BLU321
[100%conf]3000 sq ft houses-
23 Stonegate Development Harrison has building moratorium b/c of 2024 BLU321
sewer issues-3 h PM for water
24 Carlin Bay Lodge Replacement [75%conq 2024 OGA611
Application of Avista Corporation Page 7
Case Nos. AVU-E-26-

I Avista has established performance criteria in the planning horizon to mitigate
2 equipment loaded at-80% of its applicable facility rating. When equipment approaches 100%
3 of its facility ratings in real time operations, customers' power will be turned off to prevent
4 damaging equipment. In the East Lake Coeur d'Alene area, customer outages can have long
5 restoration times due to cold load pickup2 causing fuses and/or reclosers to trip.
6 3.2.4 Mitigation Plan Results
Implementation of the East Coeur d'Alene Lake System Reinforcement project results in
7 significant improvements to system performance. The results of a multi-year analysis
are shown in Table 10. The proposed Carlin Bay Station, energize year 2028. will have
8 a portion of load transferred from feeders BLU321 and OGA611 to mitigate existing
capacity constraints_ The proposed O'Gara Station rebuild, energize year 2028 after
9 Carlin Bay Station, will have load transferred from the existing O'Gara Station and
mitigates the existing capacity constraints.
10 To mitigate the high growth on BLU321 feeder, CBY641 feeder can pick up a portion of
load at Gozzer Ranch during peak winter conditions if necessary to meet system
performance criteria. This capacity for the CBY641 feeder to pick up a portion of Gozzer
11 Ranch load increases as more sections of trunk conductor are upgraded to#556 AAC.
Year Yew Year Year Year Year Yew Year yew Yew Year
12 t Ik
BLU XFMR 01 50.54 54.07 58.15 62.49 5621 00.3 64.71 6953 7474 8022 8633
13 BLU321 70.55 7531 81.01 99.24 7335 79 05 85 25 92.16 99.34
BLU322 24.51 26.08 27.91 28.4 30.30 32.52 34.81 37.25 39.86 42.66 45.91
14 ocAXFMR
X1 _78.33 8191 _85.40 -89.27 0 0 0_ 0_ 0 0 0
OGA XFMR -
15 s 1 NEW 0 D 0 0 25 03 26 12 27.25 21146 297 31 oil 324
OGA611 84.23 8805 9266 0 0 0 0 0 0 0
16 OGA611 2_ 0 0 0 0 38 39.67 41.56 4154 45-61 47.88 4999
OGA812 0 0 0 0 00 0_.
17 CKaA812 2 0 0 0 0 3023 _ 31 57 32.91 3432 3579 3732 3892
CBY XFMR
18 M1 0 0 0 0 1317 13.9 14.89_ 16.52- _ 16.42 17.32 18.37
CBY841 0 0 0 0 1691 17.97 19.11 2039 2175 23.13 24.74
CBY542 0 0 0 0 1496 1565 1634 171 1709 1855 1951
19 Table 10: Mitigation Case Winter% Loading
20 The impact of not performing this work is that Avista would not be able to reliably
21 serve an area that is experiencing significant growth. Customers will experience outages during
22 peak winter conditions when building electric heating demand is high (See Appendix A). The
z Cold load pickup is the temporary surge in electric demand that occurs when power is restored to customers
after an outage.
Application of Avista Corporation Page 8
Case Nos. AVU-E-26-

I outages may occur due to overloaded equipment tripping or failing, or Avista intentionally
2 reducing load to prevent equipment damage. The outages could impact several hundred
3 customers for multiple hours and may occur daily until peak winter loading weather conditions
4 pass. Extended outages can last multiple days and be catastrophic, not only from economic
5 loss, but customers may also face additional damage that may be caused by freezing water
6 pipes. Further customer growth in the area will increase the number of impacted customers.
7 The energization of the Carlin Bay Substation is dependent on the construction of this 115kV
8 transmission line.
9
10 V. ESTIMATED COST AND PRUDENCE OF PROJECT
11 Avista's estimated construction costs for this new 115kV transmission line is
12 approximately$30 million.Avista began exploring options for this project in 2023.Avista and
13 its consultant, Black & Veatch, conducted and completed line siting in 2023. Easement
14 acquisition began in 2025 and is ongoing. Once easements with landowners and permits with
15 agencies have been obtained and finalized, line design completion will take place. This phase
16 is anticipated to be complete in 2026. Avista anticipates construction will begin in 2027 and
17 will take approximately two years to complete. Energization of this transmission line is
18 expected to take place in late 2028.
19
20 VI. CONCLUSION
21 Approval by this Commission for an order granting the Company a CPCN to construct
22 the Carlin Bay transmission line is in the public interest and necessary to maintain adequate
23 electric service to Avista's Idaho customers on the east side of Lake Coeur d'Alene. Without
24 this new line, customers may face reliability and resource adequacy issues in the future.
Application of Avista Corporation Page 9
Case Nos. AVU-E-26-

I Constructing this new line is the most economic solution to address the system needs in the
2 area in question.
3 Avista respectfully requests that this Application be processed under Modified
4 Procedure, through the use of written comments. RP 201, et seq.
5
6 VII. REOUEST FOR RELIEF
7 WHEREFORE, Avista respectfully requests that the Commission issue an Order on or
8 before December 1, 2026, granting the Company a CPCN to construct the Carlin Bay
9 transmission line and associated facilities.
10
11 DATED at Spokane, Washington, this 7t'day of July 2026.
12 AVISTA CORPORATION
13
14 By
15 Patrick Ehrbar
16 Director of Regulatory Affairs
17 Avista Corporation
Application of Avista Corporation Page 10
Case Nos. AVU-E-26-

I APPENDICES
2 Appendix A—East Coeur d'Alene Lake System Reinforcement System Impact Study (VO)
3
4 Appendix B — East Coeur d'Alene Lake System Reinforcement Business Case Justification
5 Narrative (2025 Signed)
6
7 Appendix C—Public Meeting Materials
Application of Avista Corporation Page 11
Case Nos. AVU-E-26-