Diablo Water District is a self-governing local public agency created on May 7, 1953, under the County Water District Law of California. The District is governed by an elected five-member Board of Directors.

The District, with a staff of 14 full-time employees, obtains treats and supplies water for about 28,000 people and the parks, schools and businesses throughout a 21-square-mile area consisting of Oakley, Cypress Corridor and Hotchkis Tract, as well as Summer Lakes, and portions of Bethel Island and Knightsen.

The Diablo Water District (DWD) was formed in 1953 as the Oakley Water District. The District now serves an area of approximately 17 square miles, including the City of Oakley and unincorporated areas such as the Hotchkiss Tract, East Cypress Corridor Specific Plan Area, and Summer Lakes development; the Town of Knightsen; and certain communities on Bethel Island including Delta Coves. The District is bounded by the San Joaquin River to the north, the City of Antioch to the west, the City of Brentwood to the south, and unincorporated area to the east.

The District’s current Sphere of Influence (SOI) encompasses an additional 3.5 square miles and

includes area adjacent to the District’s southern and eastern boundaries and the Veale Tract to the southeast. The District primarily supplies treated water for domestic use and some non-potable water for park and landscape irrigation. DWD’s sources of water supply are untreated water from the Central Valley Project (CVP) purchased from the Contra Costa Water District (CCWD) and groundwater extracted from the San Joaquin Valley Basin. The surface water is conveyed through the Contra Costa Canal and treated at the Randall-Bold Water Treatment Plant (RBWTP) in Oakley. The RBWTP is jointly owned by DWD and CCWD. The plant is managed and operated by CCWD.