The Potter Valley Project, built in 1908, is a trans-basin diversion of water from the Eel River to the Russian River. The Potter Valley Project includes Lake Pillsbury, a 77,000-acre foot storage reservoir impounded by Scott Dam in Lake County. The Project also includes the Van Arsdale Reservoir, which is a storage reservoir impounded by the Cape Horn Dam, and a tunnel and penstocks that divert Eel River water to the project’s 9.4-megawatt hydroelectric power facility, located on the East Branch Russian River in Mendocino County.
The Potter Valley Project is licensed by the Federal Energy Regulatory Commission (FERC) to Pacific Gas and Electric Company (PG&E). PG&E has informed FERC that it will not pursue a new license for the project and intends to decommission the facility. This creates risk and uncertainty for both the Eel River and Russian River basin communities.
The Project currently diverts an average of approximately 60,000 acre-feet of water a year from the Eel River into the East Branch of the Russian River in Potter Valley. From there, the water flows into Lake Mendocino, providing for the needs of water rights holders along the Russian River in Mendocino and Sonoma counties. This amount of diverted water, coupled with the strategic timing of its release, is vital to all users of Russian River water.
For a comprehensive history of the Potter Valley Project, visit Mendocino County Inland Water & Power Commission’s website.