The Potter Valley Project is in Northern California in the upper Eel River and Russian River watersheds in Lake and Mendocino counties.
The project’s main storage reservoir, Lake Pillsbury, is formed by Scott Dam on the Eel River. Water stored in Lake Pillsbury is released to the Eel River and recaptured at Van Arsdale Reservoir, a 65-acre reservoir formed by Cape Horn Dam. From there, water is diverted to the Potter Valley Powerhouse, just north of the agricultural community of Potter Valley. The power generation component of the Potter Valley Project has not been operated by PG&E since 2021.
Water from the powerhouse is discharged through a canal to the East Branch Russian River or to irrigation canals operated by the Potter Valley Irrigation District to serve local farms. Flows to the East Branch Russian River are captured downstream in Lake Mendocino, which the U.S. Army Corps of Engineers operates for flood control and water supply storage used by the Sonoma County Water Agency, the Mendocino County Russian Flood Control and Water Conservation Improvement District, agricultural producers, and communities in Sonoma and Mendocino counties.
For information about PG&E’s Potter Valley Project decommissioning process visit: https://www.pottervalleysurrenderproceeding.com/