The primary source of water for 500,000 residents of the Contra Costa Water District in central and eastern Contra Costa County is the Sacramento-San Joaquin Delta.
Where the Water Comes From
Originating from rivers within the Sierra, the water flows into the Sacramento and San Joaquin rivers, eventually finding its way into the Delta.
CCWD water is drawn from Rock Slough near Oakley, Mallard Slough in Bay Point, Old River near the town of Discovery Bay and nearby Middle River.
The water is transported in the 48-mile Contra Costa Canal, which starts at Rock Slough, then stretches west to Clyde, south to Walnut Creek and north to Martinez.
CCWD can also store water Los Vaqueros Reservoir south of Brentwood, Contra Loma Reservoir in Antioch, the Mallard Reservoir in Concord and the Martinez Reservoir in Martinez.
Providing to Communities
The Contra Costa Water District treats this water and provides it to about 250,000 residents in Brentwood, Clayton, Clyde, Concord, Pacheco, Port Costa, Bay Point, and parts of Pleasant Hill, Martinez and Walnut Creek.
CCWD also sells untreated water (raw water) from the canal to the cities of Antioch, Martinez and Pittsburg, and the Diablo Water District (Oakley). These five agencies treat, distribute and bill for the water themselves, serving 250,000 people.
Most of these agencies can also draw groundwater from wells or surface water from their own reservoirs or the Sacramento or San Joaquin rivers as supplemental supplies.