The Southline Transmission Project is a proposed transmission line designed to collect and transmit electricity across southern New Mexico and southern Arizona. The project will consist of two segments:

  • A new 240-mile, 345-kilovolt double-circuit transmission line between the existing substations at Afton, New Mexico, and Apache, Arizona.
  • Upgrade of about 120 miles of WAPA’s existing transmission lines between the Apache and Saguaro substations in Arizona from a 115-kV line to a 230-kV double-circuit line. This upgrade would provide about 1,000 megawatts of capacity.

WAPA has two public involvement efforts underway for this project:

  1. Transmission customer involvement: Visit the Southline project page under TIP to see how WAPA is evaluating to what extent it will participate in the ownership of proposed project, and is currently seeking input from transmission customers to define if and how WAPA participates in this project.
  2. Environmental review process: Completed, see information below.


WAPA served as a joint lead agency with the Bureau of Land Management in preparing the environmental impact statement, or EIS, for the project.


See the BLM Southline web page for the complete EIS history.


For up-to-date information about the project, visit:

Last modified on October 17th, 2023