Los Vaqueros Reservoir - Contra Costa County, California

Los Vaqueros is the Bay Area’s largest reservoir, but I think the most beautiful that Jeff and I visited on our marathon day of visiting eight lakes in the East Bay area on 3/10/2019.  Jeff and I took a drive with our pups, Summer and Skye to the San Francisco Bay Area to take a tour of all of the lakes in Contra Costa County and a couple in Alameda County.  Los Vaqueros Reservoir is one of California’s newest reservoirs, located in the northern Diablo Range, within northeastern Contra Costa County, northern California.  Los 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.  This 1,480 surface acre reservoir at an elevation of 500 feet above sea level 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.   Water is pumped into the reservoir from a Delta intake on Old River in the Sacramento-San Joaquin Delta. The intake is located just east of Discovery Bay. Water is pumped into the reservoir when salinity is low, and used for drinking water when salinity in the Delta is too high. Water from the reservoir is released via a pipeline to the 48-mile Contra Costa Canal, which conveys water to six water treatment plants throughout the Water District's service area. The earthen dam is 192 feet high with a 1,000-foot crest length.  It is made of 2.7 million cubic yards of fill material.

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.

 

In 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 overcome many obstacles including building roads, relocating electrical and gas lines, etc.  Construction began Sept. 17, 1994.  The dam and most of the other major items were completed by December 1997. Filling of the reservoir with water began in February 1998, and was completed by January 1999, a year ahead of schedule.  One expansion was made to increase the dam and capacity of the reservoir.  More expansions to the increase the height of the dam are planned that could be completed by 2026.

The Watershed also serves as a weather data collection site for Mallory Ridge weather station located at the top of the ridge above the Marina. The station has a remote access water station (RAWS), which is maintained by the Los Vaqueros Watershed Staff and linked to the National Fire Weather System.

Other benefits of the reservoir include water storage for drought or emergencies, a protected open space, and recreation. There are 55 miles of hiking trails in the watershed. The watershed is open for fishing, hiking and other activities year-round. Electric rental boats are available, but no outside boats can be launched on the lake.  No swimming is allowed in the reservoir. 

Los Vaqueros Watershed Reservoir and Hiking Trails map located at the Marina. Did you know that Los Vaqueros is the Bay Area's Largest Reservoir and they have fun snakes that rattle, ticks with lime disease and nice Big kitty kats there too!!! Therefore, No Swimming, No Dogs or Pets, No Camping, No Fires or of course No Alcohol.... Enjoy your visit!!!