The Los Vaqueros Reservoir is located in the northern Diablo Range, within northeastern Contra Costa County, northern California.It was completed by the Contra Costa Water District (CCWD) in 1998 to improve the quality of drinking water for its 550,000 customers in Central and Eastern Contra Costa County.The reservoir is accessible via Vasco Road which connects Brentwood and Livermore. An expansion project begun in 2010 raised the height of the dam to increase storage capacity from 100,000 acre-ft to 160,000 acre-ft of water.At the start of February 2017, the reservoir contained 133700acre.ft of water.HistoryLos Vaqueros Reservoir is named for the 19th century Mexican Rancho Cañada de los Vaqueros land grant that included its site. The Spanish word vaquero means "cowboy" in English.Incursions of saline water into the Sacramento-San Joaquin River Delta from the San Francisco Bay has been a concern since the 1870s. This concern was one of the reasons CCWD was formed in 1936. A drought in 1977, caused salinity levels to exceed public health standards. It forced CCWD to ration deliveries of fresh water to its customers.Project requirementsIn 1988, voters approved funding of the Los Vaqueros Reservoir project to begin design and construction. It was a massive project. In addition to building the $61 million, 192-foot-tall dam, the district had to: build 12.8 miles of Vasco Road around the watershed at a cost of $27 millionrelocate 20 electrical towers and 12 miles of gas linebuild a new $20 million 10,000 horsepower pumping plant on Old River near Discovery Bayconstruct a new $12 million transfer station with 8,000 horsepower pumpsbuild 20 miles of 6- to 8- foot diameter buried pipeline connecting all the new facilities with district's existing canal system in Antiochsecure nearly 20,000 acres land for the dam and the watershed.make a commitment to preserving the environment and respecting Native American and other historical sites in the watershed.
