State Water Project

About the Project

The California State Water Project (SWP) is a water storage and delivery system of reservoirs, aqueducts, power plants and pumping plants. Its main purpose is to transport water to urban and agricultural water suppliers in Northern, Central and Southern California.

The SWP delivers water to two-thirds of California's population. 70% of the water goes to urban users and 30% to agricultural users. The Project is owned by the State of California and is operated and maintained by the California Department of Water Resources. The SWP includes:

  • 34 storage facilities, reservoirs and lakes
  • 20 pumping plants
  • 4 pumping generating plants
  • 5 hydroelectric power plants
  • Over 700 miles of canals and pipelines
Aerial image of a dam and surrounding area

Water Supply

The Project starts at Lake Oroville in Northern California and continues to Lake Perris in Southern California. When it reaches Lake Perris, the SWP joins in with the Metropolitan Water District system to supply water to Southern California.

State Water Project water travels through the Sacramento-San Joaquin Bay Delta (Delta) before making its way to Southern California. The Delta has experienced water quality, environmental and legislative challenges over recent years, making it important to continue to look for ways to find local water supply sources.