Northwest Marana Reliability Project
Tucson Electric Power’s Northwest Marana Reliability Project will reinforce critical systems that provide safe, reliable service and support growing energy needs in Marana and the surrounding area.
TEP has identified preferred routes for new 138-kilovolt (kV) transmission facilities to interconnect the planned Owl Head Ranch Switchyard and Grier Substation, and to interconnect the Grier Substation to a previously approved transmission line now under construction along West Marana Road. Click here to view an interactive map of these routes.
On May 2, 2025, TEP filed an application for a Certificate of Environmental Compatibility (CEC) with the Arizona Corporation Commission. The application was approved by the Arizona Power Plant and Transmission Line Siting Committee during a public hearing in June. The application must be approved by the Arizona Corporation Commission, which will consider the application in August.
More Information
- Interactive Map
- Preferred/Alternative Routes — April 2025
- CEC Application — May 2025 230mb
- Online Comment Form