Colorado River

The Colorado River makes up about 50% of the imported water supply for San Diego County. All Colorado River water is transported to San Diego County through the 242-mile Colorado River Aqueduct, which is owned and operated by the Metropolitan Water District of Southern California (MWD).

Colorado River Aqueduct Composition

  • 92 miles of tunnels
  • 5 pumping plants
  • 63 miles of concrete canals
  • 55 miles of concrete conduits
  • 144 siphons, totaling 29 miles

Colorado River

Distribution System

The Colorado River Aqueduct Project begins at Lake Havasu on the Arizona/California border and ends at Lake Mathews in Riverside County, where it becomes a part of MWD's distribution system.

Salinity levels in Colorado River water are higher than water from the State Water Project. Because of this, water from the Colorado River is blended with State Water Project water before going into distribution.

San Diego County Water Authority 2020 Diversification Plan

California water agencies continue to look for ways to reduce reliance on the Colorado River. The San Diego County Water Authority 2020 Diversification Plan aims to reduce the County's reliance on the Colorado River.