Project OVerview


Expansion of Los Vaqueros Reservoir improves Bay Area water supply reliability and water quality while protecting Delta fisheries and providing additional Delta ecosystem benefits.

The proposed project will include a regional intertie (the Transfer-Bethany Pipeline), improved pump stations and pipelines and could increase the reservoir’s capacity up to 275,000 acre-feet.

The proposed project builds upon the successful first phase of expansion from 100,000 to 160,000 acre-feet funded by the Contra Costa Water District and completed in 2012.

Los Vaqueros is one of the projects being evaluated in the context of a broader Bay Area effort to work collaboratively as a region to improve water supply reliability.

Phase 2 Los Vaqueros Reservoir Expansion Project Fact Sheet (PDF)

Los Vaqueros Reservoir Expansion Fact Sheet Image

Latest Project Updates

  1. California Water Commission Determines Continued Eligibility of the Project

    October 20, 2021 The California Water Commission unanimously voted that the Los Vaqueros Reservoir Expansion Project met all Water Storage Investment Program requirements and remains eligible for Proposition 1 funding. Read on...
  2. Los Vaqueros Reservoir Joint Powers Authority Formed

    October 7, 2021 The Los Vaqueros Reservoir Expansion Project passed a significant milestone today in officially filing agreements needed to form a Joint Powers Authority. This important milestone brings us one step closer to Project implementation. Read the news release.
  3. Members of Congress Sign Support Letter for Los Vaqueros Reservoir Expansion

    April 2, 2021 Congressman Mike Thompson, along with several members of Congress, signed a letter of support urging the Department of the Interior to provide FY 2022 funding for Phase 2 of the Los Vaqueros Reservoir Expansion Project. Read on...
  4. CWC Authorizes Changes in Funding Projects

    January 20, 2021 The California Water Commission authorized changes to maximum conditional awards for projects funded through the Water Storage Investment Program based on inflation and additional available funds. Read on...
  5. Trump Administration advances western water storage projects

    December 30, 2020 Reclamation is partnering with CCWD to pursue the Los Vaqueros Reservoir Expansion project. This legislation invests an additional $11.95 million on top of the previously approved $2.16 million in federal funds. Read on...
  6. CSU Civil Engineers Build Model to Test Design for $900M California Dam Project

    October 28, 2020 Colorado State University’s Hydraulics Lab recently demonstrated their newly constructed model of the Los Vaqueros Dam spillway and emergency outlet for stakeholders... Additional Info...
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What they are saying about Los Vaqueros Expansion

There is one dam-raising project that has drawn enthusiastic backing from environmental groups: expansion of the Los Vaqueros reservoir near Livermore. It promises to be a source of water for San Joaquin Valley wildlife refuges that often go dry in drought years.

San Francisco Chronicle
April 14, 2018

...Raising Los Vaqueros’ earthen dam by 55 feet has has drawn widespread support from both environmentalists and water agencies, including the Santa Clara Valley Water District and East Bay Municipal Utility District. It would provide storage for 275,000 acre feet of water, enough to meet the needs of an additional 575,000 people.

Mercury News & East Bay Times Editorial Boards
January 23, 2018

Expanding Los Vaqueros Reservoir is an innovative project that embodies what the voters approved when they passed Proposition 1, including significant, well-defined public benefits for the environment.

George Miller, Member of Congress, Retired
August 9, 2017

Working to expand water supplies for California’s next drought, a coalition of 12 Bay Area water agencies took a significant step Monday toward an $800 million expansion of one of the largest reservoirs in the Bay Area — Los Vaqueros Reservoir in the rolling hills near the Alameda-Contra Costa county line.

San Jose Mercury News
July 3, 2017

Additional flexibility for the water-supply system, water to benefit urban customers in the Bay Area, water for wetlands as well as for farmers and other water users south of the delta: Those are the reasons a dozen partners have joined in support of a proposed expansion of Los Vaqueros Reservoir.

Ag Alert
June 28, 2017

Millions of Bay Area residents could get extra drought insurance against water shortages and quality problems from a proposed $800 million expansion of the Los Vaqueros Reservoir that may have up to 10 water suppliers as partners.

East Bay Times
November 5, 2016

...This plan is amazingly simple. The height of the earthen dam would be raised by 51 feet to 269 feet. That would enable Los Vaqueros Reservoir to expand its capacity from 160,000 acre-feet of water to hold 275,000 acre-feet enough to serve 1.4 million residents on an annual basis.

San Jose Mercury News Editorial
April 28, 2016