​WAPA proposes to rebuild and upgrade two, parallel, 4.8-mile-long transmission lines located between Gila and North Gila Substations and take land actions in support of portions of Arizona Public Service’s construction of a new, 12.8-mile-long, 230-kV transmission line between North Gila and a proposed TS-8 substation in Yuma County, Arizona.

WAPA’s reconstruction action involves a portion of the wood-pole Gila Knob 161-kV Transmission Line, which would be upgraded to 230-kV and rebuilt on steel structures as well as the double-circuited, wood-pole Gila North Gila 69-kV Transmission Line, which would be rebuilt as an under-build on steel structures associated with the new APS line.

WAPA’s land action entails acquiring up to an additional 50 feet right-of-way adjacent to the existing Gila Knob ROW, transferring a portion of the Gila North Gila ROW to APS, and granting APS the right for their new transmission line to cross WAPA’s Gila Substation.

WAPA’s proposed action will increase the reliability and safety of the bulk electric system by replacing wood structures with steel ones, moving away from the 161-kV standard which is no longer commonly used, and efficiently using existing transmission line ROWs.  The Gila Knob Transmission Line was built in 1943 and has been in service well beyond its projected useful life.  The Gila North Gila Transmission Line was built in 1984.  WAPA’s customer, APS, determined that this project will increase reliability and meet current and future electric load on their system.

WAPA is working cooperatively with the U.S. Bureau of Reclamation, Yuma Area Office and the U.S. Army Corps of Engineers, Los Angeles District, on this project.

Project documents:

Other related sites:

News and updates:

  • On June 22, 2015, WAPA issued a Revised Finding of No Significant Impact for the certificated route alternative, which is described and analyzed in the Environmental Assessment. The certificated route alternative is 0.5 miles longer than the proposed action because it passes east of WAPA’s Gila Substation.
  • WAPA’s partner, Arizona Public Service, plans to construct the North Gila to Orchard Transmission Line along the certificated route alternative in 2020 or 2021.  This work is described as part of Phase 1 in the Environmental Assessment.
  • In 2018, WAPA rebuilt a portion of the Gila Knob Transmission Line on the north and east sides of North Gila Substation.  WAPA plans to rebuild the portion southeast of the substation in 2020 or 2021. This work is described as part of Phase 2 in the Environmental Assessment​

Contact information:

Sean Berry
Environmental Manager
Western Area Power Administration
PO Box 6457
Phoenix, AZ 85005
Phone: 602 605 2842
Fax: 602 605 2630

Last modified on December 4th, 2023