LAKEWOOD, Colorado – Today, WAPA and Tucson Electric Power announced a joint participation agreement to rebuild approximately 60 miles of the Parker-Davis Project transmission system.

By collaborating with TEP, WAPA can upgrade a large section of the Parker-Davis Project infrastructure without increasing WAPA’s transmission rates. The rebuild will improve reliability of the system and ensure that WAPA keeps the lights on for Arizona public power customers.

The project runs through Tucson, Arizona, between the Nogales and Saguaro substations, which are adjacent to TEP’s Vail and Tortolita substations. The Vail-to-Tortolita Project consists of upgrading an existing single-circuit 115-kilovolt (kV) line owned by WAPA, replacing it with a double-circuit 230-kV line. WAPA will operate one 230-kV circuit and TEP the other. Existing wood pole structures from the 1950s will be replaced with steel monopoles.

“This partnership will deliver the benefits of more reliable and resilient power service for TEP and WAPA customers alike,” said Administrator and CEO Tracey A. LeBeau. “This project could serve as a model for how future large-scale, public-private partnerships can help upgrade our nation’s energy infrastructure.”

“The level of collaboration has been unprecedented for a project of this size and complexity,” said Erik Bakken, Vice President of System Operations and Energy Resources for TEP. “This project will benefit our customers while enabling greater integration of renewable resources, supporting our development of a cleaner, greener grid.”

TEP will fund the project, while WAPA will be responsible for project management and construction. The project is anticipated to begin in 2023 and be completed by 2026.

Under the agreement, WAPA and TEP will each own and operate a 230-kV circuit. WAPA’s circuit will be operated at 115 kV to match the existing system, so upgrades will not be required at substations. Ownership of the transmission structures will be split between WAPA and TEP. For more information, visit the project website.

The Vail-to-Tortolita Project was originally an element of the larger Southline Transmission Project. TEP purchased development rights from Southline, LLC, in 2021 for the project’s western portion. The other elements of the Southline Transmission Project, which WAPA is a participant in, include rebuilding the existing transmission line between the Nogales and Apache substations in southeastern Arizona and constructing new transmission lines between southern New Mexico and Arizona.

About WAPA: Western Area Power Administration annually markets and transmits more than 28,000 gigawatt-hours of clean, renewable power from 57 federal hydroelectric powerplants owned and operated by the Bureau of Reclamation, U.S. Army Corps of Engineers and International Boundary and Water Commission in 15 western and central states. It is part of the Department of Energy. Follow us on Twitter @WesternAreaPowr or visit the website at

About TEP: Tucson Electric Power provides safe, reliable electric service to more than 438,000 customers in Southern Arizona. For more information, visit TEP and its parent company, UNS Energy, are subsidiaries of Fortis Inc. (TSX/NYSE: FTS), a well-diversified leader in the North American regulated electric and gas utility industry. For more information, visit

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