Sites Reservoir

Sites Reservoir
Sites Reservoir
Coordinates39°21′18″N 122°20′29″W / 39.35500°N 122.34139°W / 39.35500; -122.34139
TypeOffstream reservoir
Primary outflowsStone Corral Creek, Funks Creek
Managing agencyCalifornia Department of Water Resources
Built2024 start; 2030 completion (proposed)
Max. length13 miles (21 km)
Surface area14,000 acres (5,700 ha)
Max. depth310 ft (94 m)
Water volume1.8 million acre-feet (2.2 km3)
(max. as proposed)
Surface elevation580 ft (180 m)

The Sites Reservoir is a proposed offstream reservoir project west of Colusa in the Sacramento Valley of northern California to be built and operated by the Sites Project Authority. The project would divert water from the Sacramento River upstream of the Sacramento–San Joaquin River Delta through existing canals to a new reservoir 14 miles (23 km) away. Annual yield would depend on precipitation and environmental restrictions.

Construction is planned to begin in 2027 with operations targeted to begin by 2034. The project is estimated to cost $3.9 billion and is funded by local, state, and federal public dollars. In 2018, the project was awarded $816 million in funding from California's Proposition 1 water bond, and secured a $449 million investment from the United States Department of Agriculture. The United States Bureau of Reclamation is also a significant project partner.

The reservoir would be operated as part of the California State Water Project (SWP). Estimated economic benefits are around $260 million per year, with an operating cost of $10–20 million. About 30 public water agencies, public irrigation districts, counties, and cities in California have tentatively committed funding based on a beneficiary pays principle.