A plan to install a tunnel beneath a 45-mile stretch of the Sacramento-San Joaquin Delta has moved closer to final approval after a state agency determined most of the project’s certification was consistent with a regulatory plan.
The Delta Stewardship Council voted 6-1 last week to return two issues related to the Delta Conveyance Project back to the California Department of Water Resources for further review, while rejecting most appeals filed by 10 groups challenging the project’s compliance with policies.
The seven-member council was created by the state Legislature in 2010 and was charged with developing an enforceable Delta Plan to meet the goals of balancing a reliable water supply while maintaining a protected Delta ecosystem.
The council directed DWR to revisit two issues before final certification: whether the tunnel would improve conditions for the non-native invasive golden mussel; and potential conflicts involving one of the tunnel’s major construction sites near the town of Twin Cities, just south of Sacramento, and the Harvest Water program, run by the Sacramento Area Sewer District that addresses groundwater recharge and ecosystem protections for local species. That includes the sandhill crane, which is listed as threatened under the California Endangered Species Act.
The decision allows the state to continue advancing permitting for the proposed 36-foot diameter tunnel, which is intended to move excess rain and floodwater through the Delta and deliver it directly into the State Water Project.
The State Water Project is a 700-mile network of canals, hydroelectric generators and pumping plants that moves and stores water used by 27 million people and on 750,000 acres of farmland. It is used by 29 public water agencies, largely based in the South Bay, Central Coast, South Coast, Inland Empire and Kern County.
According to a news release from the office of Gov. Gavin Newsom, California is expected to lose 10% of its water supply due to hotter and drier conditions by 2040, threatening to reduce the reliability of the State Water Project by as much as 23%. The Delta Conveyance Design and Construction Authority, which will oversee the tunnel’s construction, estimates the building will begin in 2035.
“During the atmospheric rivers last year, the Delta Conveyance Project could have captured enough water for 9.8 million people’s yearly usage,” the statement said. “We are closer than ever to seeing this important piece of infrastructure completed and benefiting all Californians. Let’s get this built.”