San Luis Transmission Project

The proposed San Luis Transmission Project comprises 95 miles of new transmission lines within easements ranging from 125 to 250 feet wide through Alameda, San Joaquin, Stanislaus, and Merced Counties along the foothills of the Diablo Range in the western San Joaquin Valley, California.

The proposed San Luis Transmission Project includes construction, operation, and maintenance of:

  • a new 500-kilovolt (kV) transmission line about 65 miles in length between the new Tracy East and Los Banos West Substations;.
  • a new 230-kV transmission line about 3 miles in length between Pacific Gas and Electric’s (PG&E) existing Los Banos Substation or the new Los Banos West Substation and Western’s existing San Luis Substation;
  • a new 230-kV transmission line about 20 miles in length between Western’s San Luis Substation and Western’s existing Dos Amigos Substation or a new 230 kV transmission line about 18 miles in length between the new Los Banos West Substation and Western’s existing Dos Amigos Substation;
  • an interconnection with the existing Western 500-kV Los Banos–Gates No. 3 transmission line just south of PG&E’s Los Banos Substation into the new Los Banos West Substation;
  • a new 70-kV transmission line about 7 miles in length between the existing San Luis and O’Neill Substations; and
  • substation improvements, communication facilities, improvements to existing access roads, new permanent access roads, and temporary access roads to facilitate construction activities.

Why is SLTP needed?

The United States Department of Interior, Bureau of Reclamation entered into a contract with PG&E in 1965 for power transmission service between Western’s Tracy Substation and Reclamation's San Luis Unit facilities. The existing transmission contract with PG&E expires in March 2016, and PG&E has stated it will not renew it. Although transmission service is available under the California Independent System Operator Tariff after March 2016, that service would substantially increase Reclamation’s transmission costs compared to service under PG&E’s contract. Reclamation submitted a transmission service request to Western to consider various transmission service arrangements, including the construction of new federal transmission lines, to support Reclamation’s continued economic delivery of federal water after the PG&E contract expires.

Also, in October 2013, an eligible transmission customer submitted a transmission service request to Western for transmission service within the same area requested by Reclamation. Western is evaluating both requests jointly in order to determine if it can satisfy Reclamation’s need and the eligible customer’s request with a single project.