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
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.