Project overview

This maintenance project will consist of rebuilding and reconductoring existing high-voltage transmission line infrastructure from Idaho to Utah. The project involves the following substations: Populus, Bridgerland, Ben Lomond, Threemile Knoll, Soda, Grace, Oneida and Treasureton. The project will be completed in two phases.  The first phase will focus on the 67-mile, 345 kV reconductor that anticipates completion by the end of 2028. The second part of the project will focus on the 40-mile, 138 kV rebuild that anticipates completion by the end of 2030. This project will increase overall system reliability while improving capacity.

About the project

The purpose and need for the Populus to Terminal Segment B project rebuild is to ensure the transmission system is reliable. Due to increased electrical demand, the existing transmission infrastructure will not have sufficient capacity to reliably serve future load requirements. This reconductoring and rebuild will provide additional capacity to help in serving load growth while increasing overall system reliability. 

Phase 1

• Approximately 67 miles of reconductor of the Ben Lomond-Populus East 345 kV line between the Populus substation in Downey, Idaho, and the Honeyville Crossover in Honeyville, Utah.

Project area

PacifiCorp is working with a variety of stakeholders for phase 1 of this project, including:

• U.S. Bureau of Land Management
• U.S. Bureau of Reclamation

• Cache County
• Box Elder County
• Cornish Town
• Deweyville Town
• Honeyville City

• Franklin County
• Bannock County
• Weston City

Map

Segment B Honeyville to Populus and Threemile Knoll - Phase 1 Project Map

Project timeline

345 kV Rebuild, Populus to Honeyville (phase 1)

• Survey and right-of-way: June 2025 – March 2028
• Permitting: Jan 2026 – Jan 2028
• Construction: Jan 2028 – Oct 2029       
• In-service: Q4 2029

After providing a project introduction to local jurisdictions, PacifiCorp will provide opportunities to inform the public of the project and will answer questions. Throughout the permitting process, it is anticipated that local jurisdictions along the project route may require additional public outreach and engagement. Information about all open-house meetings and engagement opportunities will be noticed and can also be found on this page. 

Public outreach

Stakeholder briefings are underway. As we initiate the pre-construction and permitting phase, we will begin public outreach. More information will be made available soon.

Additional information

Requests for additional information on the Populus to Terminal Segment B project may be directed to pmopac@PacifiCorp.com. Please include the word “Segment B” in the subject line and provide your contact information and preferred contact method in the body of the message.