about the project

Welcome to the Bay Area Regional Desalination Project Website

Five Bay Area water agencies are working together to investigate a regional water supply project using desalination and water transfers to serve the needs of over 5.6 million residents and businesses in the region. The Contra Costa Water District (CCWD), the East Bay Municipal Utility District (EBMUD), the San Francisco Public Utilities Commission (SFPUC), and the Santa Clara Valley Water District (SCVWD) have collaborated in this effort since 2003. In 2010, Zone 7 Water Agency (Zone 7) joined the group to evaluate this project.

Over the years, as individual needs of the participating agencies have changed, so has the proposed role of the Bay Area Regional Desalination Project (BARDP) as a regional water supply option.  What started out as a proposed 120 mgd plant to be used during major facility outages and emergencies, has become a concept to locate a 10-20 million gallons per day (mgd) desalination treatment facility in eastern Contra Costa County to turn brackish water into a reliable, drought-proof drinking water supply. As is currently envisioned, the desalination facility would operate in all year types, serving the all-weather needs of the SFPUC and Zone 7 and banking the excess production for the agencies’ dry year needs - saving water for a dry day. Brine discharged from the plant would be blended with effluent from one or more nearby wastewater treatment plants to stay within ambient water quality, mimicking the current water conditions as closely as possible.

The project concept relies on available capacity in an extensive network of existing pipelines and interties that already connect the agencies, as well as existing wastewater outfalls and pump stations in the region. The only new infrastructure envisioned for the project would be a treatment plant and connections to the network of interconnections that would already be in place. Once treated, water could be delivered through either EBMUD or CCWD’s conveyance systems via transfers to other partner agencies (shown on map). Storage at Los Vaqueros Reservoir may also be available to project partners to better serve the needs of the participating agencies, particularly during dry years.

The agencies have recently completed site-specific studies to answer some key questions. The results of these studies are summarized as follows:

  • Hydraulic modeling completed by EBMUD verified that up to 20 mgd could be wheeled to the Hayward Intertie at least 90% of the year, and 10 mgd to Zone 7 through a planned intertie over 95% of the year (assuming 2040 system demands and planned improvements).
  • Operations of a 20 mgd plant at Mallard Slough would not have a significant impact on water quality or beneficial uses in the area under existing or forecast conditions (<0.25% change in salinity).
  • Sensitive fish species are present in the vicinity of the treatment plant in February – May, and mitigation for any potential impacts could be incorporated into the project design.
  • Energy use and associated greenhouse gas emissions are less than other desalination projects because of  brackish Bay (not ocean) source water. They would be even lower except that pumping and treatment for delivery routes adds energy consumption. Use of existing facilities also lower the project’s overall environmental footprint.
  • Modeling based on hydrologic history indicates that use of Los Vaqueros Reservoir could help meet over 80% of agencies’ collective drought needs.

With these studies completed, the agencies have determined the Bay Area Regional Desalination Project is technically feasible. The next step is to revisit the role of the project within the context of each agency’s changing water supply and demand picture through 2030. While each agency continues to evaluate its need for the project, the agencies are collectively embarking on a study to look more broadly at all the available opportunities to optimize the sharing of water resources across the region. In this context, the agencies will consider the use of existing supplies as well as new supply through desalination. By taking a more holistic and regional approach to water supply planning, the agencies hope to make the best use of scarce resources to serve the future needs of the Bay Area.

Additional information will be shared as it becomes available.

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whats new


  • Public Workshop - 4/20/2013
    10:30 am to 12:30 pm., SF Main Library, Koret Auditorium, San Francisco, CA.
    April 20, 2013 Flyer

  • Public Workshop - 4/24/2013
    6:00 pm to 8:00 pm., East Bay Municipal Utilities District (EBMUD), 374 11th Street, Oakland, CA.
    April 24, 2013 Flyer


  • Public Workshop - 10/25/12
    CalDesal Conference in Sacramento, CA.

  • Public Workshop - 9/26/12
    San Jose State University “Green Talk Brown Bag”, September 26, 2012, Noon to 1:00 pm, Engineering Auditorium, San Jose State University. Workshop Documents:
    Session 1
    Session 2

  • Public Workshop - 9/18/12
    Sierra Club, Bay Delta Group presentation, September 18, 2012, at 7:15 pm, Antioch Library, 501 West 18th Street, Antioch, CA.
    Workshop Documents:

  • Public Workshop - 8/21/12
    American Water Work Association’s Desalination Workshop: “Desalination Update for the West: What’s New? What has Changed? Where is it Going?”, August 21, 2012, City Hall – Facilities, Foster City, CA.

  • Public Workshop - 5/29/12
    Come to a public workshop about the status, potential benefits and potential environmental drawbacks of the Bay Area Regional Desalination Project on May 29, 2012 in Redwood City, CA.

    Workshop Documents:
    Document 1
    Document 2

  • Sierra Club Workshop - 3/31/12
    The Sierra Club Bay Chapter sponsored a free public workshop about the status, potential benefits and potential environmental drawbacks of the Bay Area Regional Desalination Project on March 31, 2012 in Oakland, CA.

    Workshop Documents:
    Session 1 Presentation
    Session 3 Presentation
    Fact Sheet

    Contra Costa Council Environmental/Manufacturing Task Force - Desalination in the San Francisco Bay Area

  • 2011

    Request For Proposal
    BARDP Green House Gas Analysis - Dec 21, 2011

    Institutional Feasibility Analysis TM - Analysis of Feasible Scenarios (2011)

    Memorandum of Agreement (2011)


    Pilot Plant Operation at Mallard Slough (2009)

    Pilot Plant Testing at Mallard Slough Engineering Report, 2010

    Entrainment and Source Water Study Report, By Tenera Environmental Inc., 2010

    Existing Facilities Evaluation by URS, 2010