The North Bay Aqueduct (NBA) is part of the State Water Project (SWP). The SWP has rights to water originating from the Sacramento and San Joaquin Rivers, and it stores water in Lake Oroville. The NBA was envisioned as part of the SWP during the 1950's and 1960's when the SWP was being planned. Initial NBA water service in the SCWA service area went to Benicia and Vallejo. In 1990 the North Bay Regional Water Treatment Plant, serving Fairfield and Vacaville, came on line and was able to treat water from the NBA for these two cities. The NBA cost approximately $83 million to construct.
The NBA is an underground pipeline that runs from Barker Slough in the Delta to Cordelia Forebay, just outside of Vallejo. From the Cordelia Forebay water is pumped to Napa County, Vallejo and Benicia. Travis Air Force Base is also served off the NBA. The size of the underground pipeline varies from 72 inches at Barker Slough to 54 inches at Cordelia Forebay. The NBA is operated remotely by the State Department of Water Resources (DWR) at the Delta Field Division office near Tracy.
The NBA cannot deliver the full 175 cfs flow it was designed and contracted for. Pumping tests have shown that the NBA can deliver a maximum of 142 cfs. DWR, SCWA and Napa County are investigating methods to increase the capacity of the NBA at least to the contract amount of 175 cfs.
The NBA diverts this water from Barker Slough, in the Delta, to the Solano agencies for water supply. The major SWP facilities that deliver water to the Solano agencies include:
Barker Slough Pumping Plant, which pumps water from Barker Slough into the NBA;
North Bay Aqueduct, a pipeline that delivers water from Barker Slough to Cordelia Forebay: and
Cordelia Forebay, where water is pumped to Napa County, Vallejo, and Benicia.
Please click here to view the North Bay Aqueduct Alternate Intake flier (PDF).