The Source of Your Water

The primary source of water for 550,000 residents of the Contra Costa Water District in central and eastern Contra Costa County is the Sacramento-San Joaquin Delta.

Sacramento/San Joaquin Delta Map

Map of CCWD Service Area

Aerial Photo of Los Vaqueros Reservoir

For more information on CCWD water quality, Click here

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, Old River near the town of Discovery Bay and Mallard Slough in Bay Point.

The water is transported in the 52-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 in the Los Vaqueros Reservoir south of Brentwood, the Contra Loma Reservoir in Antioch, the Mallard Reservoir in Concord and the Martinez Reservoir in Martinez.

The Contra Costa Water District treats this water and provides it to about 265,000 residents in Brentwood, Clayton, Clyde, Concord, Pacheco, Port Costa, 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, the California Cities Water Company (Bay Point), and the Diablo Water District (Oakley). These five agencies treat, distribute and bill for the water themselves, serving 285,000 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.