Environmental Resources

Where your water comes from

The primary source of water for residents of the City of Antioch is the surface water of the Sacramento-San Joaquin Delta. Originating from rivers within California’s mountain ranges, the water flows into the Sacramento and San Joaquin rivers, eventually finding its way into the Delta. The City operates a Water Treatment Plant and distribution system, providing drinking water to all customers within the city limits.

The City purchases the majority of our water from the Contra Costa Water District (CCWD) which is then treated and distributed to our customers. CCWD draws water 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 Contra Costa Canal, which starts at Rock Slough, then stretches west to Clyde, south to Walnut Creek and north to Martinez. CCWD also stores 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. CCWD canal water can be pumped to Antioch’s Water Treatment Plant or the Municipal Reservoir.

The City of Antioch also manages a pumping station on the San Joaquin River. Water is pumped from the river into the City’s Municipal Reservoir. That water is then sent to the Water Treatment Plant (WTP), where it is made safe for drinking.