Eastern Plains Transmission Project

The Eastern Plains Transmission Project (EPTP) is Tri-State’s proposed high-voltage transmission system across eastern and southern Colorado.  The EPTP will assist Tri-State to serve the long-term needs of its member systems, enhance power delivery system reliability in the region, relieve existing constraints and provide opportunities for additional interconnections, including those from renewable energy projects.

The EPTP and other regional transmission projects are being evaluated as part of the Colorado Long Range Transmission Planning Group (CLRTPG) 2018 transmission planning study.  Tri-State and other regional utilities and transmission providers participate in the CLRTPG, which provides a forum for electric load-serving entities in the region to jointly explore the potential for the development of a coordinated transmission network.

Tri-State is evaluating its members’ needs, and with other utilities, is evaluating regional system requirements that could change the scope of EPTP.

Because of the potential changes in the scope of EPTP, the Western Area Power Administration has cancelled work on an environmental impact statement for the EPTP.  The EIS was required under the National Environmental Policy Act (NEPA) as part of Western’s proposed participation in the EPTP.  Western’s notice states that preparation of the EIS is being cancelled due to anticipated changes in the EPTP scope.  If Western was to participate in the re-defined EPTP, a NEPA review will be initiated at that time.

On October 9, 2008, Tri-State announced an agreement with Xcel Energy to begin technical studies to determine the feasibility of joint transmission projects in southern and eastern Colorado, including portions of the EPTP.

Tri-State will continue to work with its members, the CLRTPG and other utilities to evaluate regional transmission requirements as it moves forward to route, permit and construct segments of the EPTP.