Bay Area Regional Reliability

Bay Area Regional Reliability (BARR) 

BARR Mitigation Measures

BARR Mitigation Measures

Bay Area Regional Reliability is a partnership of eight Bay Area water agencies to address water supply reliability concerns and drought preparedness on a mutually-beneficial and regionally -focused basis.

The BARR Partners collaboratively developed a Drought Contingency Plan (DCP) to respond to droughts from a regional, integrated perspective. The DCP assessed the vulnerability of the region’s critical water resources and identified 15 drought mitigation measures to improve regional water reliability and resilience. EBMUD is involved in the following seven mitigation measures, which are discussed below:

  • Bay Area Shared Water Access Program (SWAP)
  • Los Vaqueros Reservoir Expansion
  • MMWD-EBMUD Intertie
  • Regional Advanced Metering Infrastructure Feasibility Assessment
  • Regional Desalination
  • Walnut Creek Water Treatment Plant (WTP) Pre-Treatment
  • Zone 7-EBMUD Intertie

Bay Area SWAP (Previously called Regional Water Market)

The objective of SWAP is to outline a process (roadmap) to make it easier for Bay Area water agencies to exchange and transfer water during droughts. The BARR Partners are currently developing a strategy report with input from the SWAP Stakeholder Task Force to establish a framework and path forward to support regional access to water supplies. EBMUD, acting on behalf of the BARR partners, is managing a $400,000 grant from the United States Bureau of Reclamation that is partially funding this project.

Los Vaqueros Reservoir Expansion

Los Vaqueros Reservoir

Los Vaqueros Reservoir

EBMUD is evaluating potential participation in Contra Costa Water District’s (CCWD) proposed expansion of Los Vaqueros Reservoir along with ACWD, BAWSCA, Grassland Water District, SFPUC, San Luis & Delta-Mendota Water Authority, Valley Water, and Zone 7. The Project would expand Los Vaqueros Reservoir from 160 thousand acre-feet (TAF) to 275 TAF.

If EBMUD participates, the project would create additional off-stream storage, provide supplemental water supply for droughts and emergencies, and increase adaptability to climate change by allowing storage when water supply is available. In addition, the Project will also result in additional environmental flows for the Mokelumne River, while making water supply available for wildlife refuges in California’s Central Valley.


This project is at the conceptual stage and envisions connecting EBMUD’s and MMWD’s water delivery systems either with a pipeline across the Richmond-San Rafael Bridge or across the bottom of the Bay, providing potential water sharing and transfer opportunities.

Regional Advanced Metering Infrastructure (AMI) Feasibility Assessment

Advanced Metering infrastructure (AMI) is technology which allows water agencies and customers to receive real-time data from their water meters. This information can help customers use water wisely and catch water-wasting leaks. The regional AMI feasibility assessment is currently conceptual, though some agencies are further along than others in planning or implementing AMI within their respective service areas. EBMUD’s current AMI project, the Phase I AMI project, includes 13,000 customer accounts distributed throughout the service area. The goal of this project is to quantify the water and energy savings for customers that receive more real-time water consumption data from an AMI system.

Regional Desalination

CCWD, SFPUC, Valley Water, and Zone 7 are evaluating the potential for a regional desalination project. EBMUD’s current role in the regional desalination project is limited to potentially conveying water supply for the Bay Area agencies that are evaluating the project. Additional information on the location, size, and timing of the regional desalination project can be found in the UWMPs of the four main water agencies evaluating the project.

Walnut Creek Water Treatment Plant (WTP) Pre-Treatment

Walnut Creek Water Treatment Plant

Walnut Creek Water Treatment Plant

EBMUD plans to add pre-treatment to the Walnut Creek WTP, increasing flexibility to treat supplemental water supply from different sources, including the Sacramento River and Los Vaqueros Reservoir. The upgrades will improve regional reliability by increasing EBMUD’s capacity to convey water for other Bay Area agencies and will allow for interconnections with raw water supplies from neighboring agencies. Planning and pre-design activities are underway for this project. Currently, EBMUD is planning to update the plant in phases. Half of the plant will initially be upgraded to full treatment capability, treating up to 80 MGD. A planned future phase would upgrade the other half of the plant, allowing full treatment up 160 MGD, enough to meet EBMUD’s long-term needs.

Zone 7-EBMUD Intertie

This project is at the conceptual stage and envisions connecting EBMUD’s water delivery system to Zone 7’s system, providing potential water sharing during emergencies and transfer and exchange opportunities.

A shared vision

The eight BARR Partners consist of:

  • Alameda County Water District (ACWD)
  • Bay Area Water Supply and Conservation Agency (BAWSCA)
  • Contra Costa Water District (CCWD)
  • East Bay Municipal Utility District (EBMUD)
  • Marin Municipal Water District (MMWD)
  • San Francisco Public Utilities Commission (SFPUC)
  • Santa Clara Valley Water District (Valley Water)
  • Zone 7 Water Agency (Zone 7)

After adopting principles in 2014 to guide the partnership, the agencies executed a Memorandum of Agreement in 2015, which was subsequently amended in 2019.

For more information

Grace Su, Associate Civil Engineer
Email: Grace Su
Phone: 510-287-7013