Contra Costa Water District

It is now one of the largest water districts in California, serving about 500,000 people in Central and Eastern Contra Costa County.

Farmers could not afford the expense of importing water, and had to stop irrigating crops, which caused the value of land to decline.

[1] A citizens' group calling itself the Bay Barrier Association was formed to lobby for a solution to the problem of seawater intrusion.

The California Central Valley Project Act authorizing construction of structures and waterways including the Contra Costa Canal was passed in 1933 and approved by Governor James Rolph.

[a] Despite delays caused by demands for labor and materials needed of World War II, the 48 miles (77 km) long tunnel was completed in 1948, from the Delta intake on Rock Slough (near Knightsen) to Martinez.

Later CCCWD bought all of CWSCs holdings in Contra Costa County, including its treatment, pumping, storage and distribution facilities.

It was designed with a capacity of 2,000 acre-feet (2,500,000 m3) to serve for peak storage and emergency supply for the Contra Costa Canal.

[1] In 1988, CCWD sought voter approval of the Los Vaqueros proposal that included building a 100,000 acre-feet (120,000,000 m3) reservoir inside a 20,000 acres (81,000,000 m2) watershed.