Yuba-Bear Hydroelectric Project

The Yuba-Bear Hydroelectric Project is a complex hydroelectric scheme tapping the Middle and South Forks of California's Yuba River and the upper Bear River in the northern Sierra Nevada for power generation. The project area encompasses approximately 400 square miles (1,000 km²) in Nevada, Placer, and Sierra Counties. This project consists of eight major dams and reservoirs, four diversion dams, and four generating stations producing about 425 million kilowatt hours of electricity each year. The project was completed in 1966 by the Nevada Irrigation District for both power production and water storage, and power is distributed under contract with Pacific Gas and Electric (PG&E).^[1] The project's reservoirs have a gross storage capacity of 203,865 acre feet (0.251464 km³).^[2]

Water from the Middle Yuba River is stored in the reservoir behind Jackson Meadows Dam and released to a diversion at Milton Reservoir, which sends the water into the South Yuba River drainage, where it is stored behind Bowman Dam on Canyon Creek (a tributary of the South Yuba River). From here it is diverted further south to the larger Lake Spaulding, which is part of the separately owned but interconnected PG&E Drum-Spaulding Project. From Lake Spaulding another tunnel transports the water into the Bear River watershed, where it flows into Rollins Reservoir and eventually meeting further diversion to the North Fork American River.^[3] The water steadily descends as it passes through the various river basins and supplies power to several hydroelectric stations along the way with a combined capacity of 79.32 MW. Various smaller diversion and storage dams serve to increase and regulate the water flow available for power generation. In addition to hydroelectric power the project increases the water flow in the Bear and American Rivers, providing for irrigation and municipal uses in those watersheds.^[2]

Together with the heavily interconnected Drum-Spaulding Project, an earlier hydroelectric project on the forks of the Yuba River, the Yuba-Bear project is considered by the Federal Energy Regulatory Commission to be "the most physically and operationally complex hydroelectric project in the United States".^[4]

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