Western Area Power Administration (WAPA) in partnership with Duke-American Transmission Co. (DATC) is proposing to build and operate the San Luis Transmission Project – a new 85-mile, 230-kilovolt electric transmission line that will continue to provide the electricity necessary for the economical and reliable delivery of federal water supplies to San Joaquin Valley and Bay Area residents, businesses and farms. It will run from WAPA’s Tracy Substation in the north to the San Luis, O’Neill and Dos Amigos substations in the south.

Click here to download a map of the project.

Project Benefits

  • Provide cost certainty: Limits cost increases for water customers and provides long-term cost certainty
  • Enhance reliability: Strengthens the transmission corridor between Tracy and Los Banos areas and enhances delivery of energy and water supplies
  • Enable renewable energy: Strategically positions the San Joaquin Valley for expansion of renewable energy projects; expands transmission access and flexibility to help the state meet its renewable energy and greenhouse gas reduction goals
  • Strengthen the transmission grid: Enhances energy transmission, improves transmission system reliability in the entire San Joaquin Valley and prevents catastrophic outages
  • Use an existing corridor: Relies on effective use of an existing transmission corridor to minimize costs and farm and environmental impacts

Background and Need

WAPA is a federal agency, one of four power marketing administrations within the U.S. Department of Energy, whose role is to market and deliver clean, renewable, reliable, cost-based federal hydroelectric power from multi-use water projects. As a wholesale power provider, WAPA delivers power from 56 power plants operated by the Bureau of Reclamation, U.S. Army Corps of Engineers and other federal entities, including the Central Valley Project in California.

WAPA is required by law to provide reliable, electric transmission service to Reclamation and its customers. WAPA’s transmission contract with Pacific Gas & Electric for delivery of San Luis Unit power at the federal Central Valley Project expired in 2016, and Reclamation requested that WAPA develop the San Luis Transmission Project to replace the expiring contract.

About the Project

WAPA is the federal lead agency for the San Luis Transmission Project, developing the project for Reclamation and its San Luis Unit of the CVP. The San Luis & Delta-Mendota Water Authority, which serves many of the federal water contractors, is the state lead agency for the transmission line project.

The project has received the required permits as part of the National Environmental Policy Act process permits and is projected to be in service in 2023.

Construction of the proposed transmission line is the least-cost and most reliable long-term option for local water agencies as well as California electric users generally. Specifically, the proposed transmission line will enhance delivery of low-cost WAPA power for use by San Joaquin Valley and Bay Area water agencies and farms. The project is expected to provide long-term power supply reliability and cost certainty for all SLDMWA and other CVP water customers. More than 45 water and leading farm groups support development of the transmission line.

Public-Private Partnership

The San Luis Transmission Project is benefitting from partnerships with public agencies and private organizations working to ensure the San Joaquin Valley, a region that the nation relies on to provide food for millions, continues to thrive. Together, the Department of Interior, WAPA, SLDMWA, Reclamation and DATC are collaborating to develop and realize this project – and do it in a cost-effective way.

DATC is a private transmission developer working with the public stakeholders on the SLTP project. DATC is equally owned by Duke Energy, the largest utility in the nation, and American Transmission Co., a national leader in transmission development. Collectively DATC partners own and operate more than 41,000 miles of transmission lines. As a transmission-only utility, DATC provides valuable insights into meeting transmission infrastructure needs.

Public-private partnerships can provide notable advantages in infrastructure projects, and can be especially useful in critical, regionally significant projects, such as the San Luis Transmission Project. In this project, DATC provides project execution expertise. Public stakeholders benefit from DATC’s transmission expertise while also securing a predictable, reliable transmission connection to support the water and power needs of the Central Valley.

DATC’s expertise can help maximize efficiencies in the project and drive down costs. By maximizing the line capacity, others could benefit from the project, such as utilities in the area serving end users and renewable energy developers. Reclamation, WAPA, SLDMWA and DATC are working together to identify ways to design and build the line that provide for additional capacity above what WAPA requires, and do it in an efficient and cost-effective manner.

DATC is financing the project in its entirety and will offer all of the transmission capacity in accordance with the provisions of WAPA’s Open Access Transmission Tariff. DATC submitted a filing to FERC (ER19-1338) on March 15, 2019, to establish conditions for the capacity release. The amount of capacity available will be contingent upon final determination of capacity needs to serve Reclamation.