Los Vaqueros

Press file photo

A major expansion of the Los Vaqueros Reservoir took a step forward with the release of the Final Feasibility Report by the U.S. Bureau of Reclamation (USBR) that concluded the initiative is economically viable.

The reservoir is owned and operated by the Contra Costa Water District (CCWD), and the project will increase its capacity by more than 70% when complete.

“This is a significant milestone for the Los Vaqueros Reservoir Expansion Project and project partners,” said Lisa Borba, CCWD board president. “We are grateful for our partnership with Reclamation as we move forward to make this important investment in water storage a reality.”

According to Lisa Navarro, USBR public affairs specialist, the Secretary of the Interior’s determination of feasibility and providing the Final Feasibility Report to Congress enables the USBR to move forward with permitting, advance project designs and other key project activities. Importantly, it also makes the project eligible to receive federal funding for construction costs.

“The report includes the analysis that the alternative to expand the reservoir to 275,000 acre-feet is the preferred alternative,” added Jennifer Allen, CCWD director of public affairs. “With the cost analysis that they put into the report, up to 25% of the construction can be paid for with federal dollars.”

The reservoir at Los Vaqueros, which operates as part of the federal government’s Central Valley Project, opened in 1998 with a capacity of 100,000 acre-feet. It was expanded to its current capacity of 160,000 acre-feet in 2012. The new project proposes another expansion, this one to a total of 275,000 acre-feet. An acre-foot of water is the volume of water needed to cover one acre with one foot of water. It is roughly equal to 326,000 gallons of water, about the volume of water used by two California households in a year. Looked at another way, the project would add about 37 billion gallons of water to the reservoir.

The objectives of the project are to: increase reliability of Delta water supplies; increase water supply reliability for water providers within the Bay Area; and enhance water supply reliability for wildlife refuges south of the Delta.

Allen said that while the project could have proceeded without federal support, doing so would be less than ideal if for no other reason than the costs covered by the federal government would have to be absorbed by the participating agencies.

The USBR report pegs the cost of the expansion project at $895 million. A little more than half of the cost will be paid for with a $494 million allocation from Proposition 1 that was approved in 2018. The federal government is expected to cover another 25% of the project costs. The remaining expense will be paid for by water agencies and municipalities that will benefit from the project. Participants could include the East Bay Municipal Utilities District, the San Francisco Public Utilities Commission, the Alameda County Water District and the City of Brentwood among others.

“The city has a long-standing successful partnership with the Contra Costa Water District to support regional water supply resiliency on projects like the Los Vaqueros Reservoir Expansion Project,” said Miki Tsubota, director of public works/city engineer for the City of Brentwood. “By expanding the capacity of the reservoir and constructing associated infrastructure, this project will improve regional water supply reliability and water quality.”

The Los Vaqueros Reservoir is unique in that there is no naturally occurring source feeding it. No river provides a constant inflow of water. Instead, water is pumped from the Delta from four locations, including Rock Slough in Knightsen, and transported to the reservoir through the Contra Costa Canal. That fact influences the purpose and operation of the reservoir.

“We built Los Vaqueros since we’re dependent on the Delta, and water quality in the Delta fluctuates over the seasons,” Allen explained. “We can put high quality water up there when water is good. When water quality in the Delta starts to degrade, then we can release water from Los Vaqueros to blend it for (improved) water quality. The expansion is also providing more supply reliability, not just the water quality that we’ve depended on.”

With the completion of the Final Feasibility Report, the next step will be the creation of joint powers authority (JPA), expected to be complete by the end of this year. The JPA will determine the governance of the project and coordinate efforts going forward. Construction could begin in about a year and is expected to continue through the remainder of the decade.

Allen said the project enjoys widespread support, not only from water agencies and municipalities, but environmental groups as well. One of the benefits of the expansion will be providing a reliable water source to water-starved national wildlife refuges that are located south of the reservoir.

“We are pleased to partner with CCWD on this smart expansion project that would create additional storage capacity in an existing footprint,” said USBR Commissioner Brenda Burman. “This is a win-win for the Bay Area and the Central Valley Project.”

For more information on the Los Vaqueros Expansion Project, visit www.ccwater.com.