The Federal Energy Regulatory Commission on June 8 approved a November 2015 application from the Pyramid Lake Paiute Tribe for a preliminary permit covering up to three years of feasibility work on the proposed Prosser Creek Hydroelectric Project, to be located on the Prosser Creek Dam and Reservoir on Prosser Creek near the town of Truckee in Nevada County, California.
The proposed project would be located entirely on federal land administered by the U.S. Bureau of Reclamation. The project would be located at the existing discharge channel on the downstream side of the Prosser Creek Dam. It would utilize the existing intake structure in Prosser Creek Reservoir, the existing outlet structure of the dam consisting of two 560-foot-long, 9.5-foot arched concrete conduits, and the discharge channel on the downstream side of the dam. No modifications would be made to these existing structures.
Under the Tribe’s proposal, the project would consist of these new facilities: a pressure-rated, concrete, flow-control structure located at the end of the existing low-level outlet that would include control valves to regulate flows to the proposed powerhouse or direct flows to the existing discharge channel during a powerhouse outage; a 48-inch-diameter penstock to convey water from the existing outlet structures to the powerhouse and direct flow to one or both of the generating units via a common header and control valves; an approximately 32-foot-wide by 62-foot-long by 33-foot-high powerhouse located on the east side of the primary discharge channel outlet containing two Francis generating units, one smaller 790-kW unit and one larger 2.7-MW unit for a total rated capacity of 3.49 MW; a 50-foot-long tailrace channel extending from the proposed powerhouse to meet the existing outlet channel; a channel training wall leaving the powerhouse on the landside of the tailrace channel; and a 650-foot-long, 69-kV transmission line and electrical substation to interconnect the proposed project to the existing, nearby 69-kV transmission line owned by Liberty Utilities.
The Tribe proposes to develop the proposed project in conformance with the operation of Prosser Creek Dam by the Bureau of Reclamation under the terms of the Truckee River Operating Agreement (TROA) and would generate electricity using the existing flow releases under the terms of the TROA. The estimated annual generation of the Prosser Creek Hydroelectric Project would be 7.4 gigawatt-hours.
The purpose of a preliminary permit is to preserve the right of the permit holder to have the first priority in applying for a license for the project that is being studied.