Metropolitan Board approves planning role in Northern California reservoir project

Los Angeles — Looking to possibly increase Southern California’s future water reserves and better position the region to address climate change, Metropolitan Water District’s Board of Directors approved an initial down payment to participate in a proposed large off-stream reservoir in Northern California.

The board unanimously authorized $1.5 million to join the first planning phase of the proposed Sites Reservoir aimed at securing state grant construction funds from Proposition 1. While the action does not guarantee Metropolitan’s future involvement in the building of the planned reservoir about 80 miles north of Sacramento, it provides the district an initial option of up to 50,000 acre-feet of annual water yield.

“This modest stake gives Southern California a seat at the table as Sites Reservoir begins to take shape. It also enhances the good faith effort being made by water agencies throughout the state to increase stored surface water in California, particularly in facing the uncertainties of climate change,” said Metropolitan board Chairman Randy Record.

“Southern California certainly understands the value of having water reserves. During the drought, we were able to draw on our record storage to meet demands with as little impact on consumers and businesses as possible,” Record said.

The Sites Reservoir Project, with a preliminary cost estimate of $4.4 billion, proposes construction of two large dams and nine small saddle dams to store up to 1.8 million acre-feet of water. Most of the supplies would be diverted through existing facilities from the Sacramento River during high water flows. (An acre-foot of water is nearly 326,000 gallons, about the amount used by two typical Southern California families in a year.)

The proposed project — the seventh largest reservoir in California, if built — could yield an estimated 500,000 acre-feet of water in an average year. It also could provide supplies for the environment as well as flood control, recreation and other public benefits. Construction could begin in 2022, with the reservoir expected to be operational by 2029.

Metropolitan General Manager Jeffrey Kightlinger said the additional storage north of the Sacramento-San Joaquin Delta offered by Sites Reservoir would be more valuable with the implementation of California WaterFix. The WaterFix proposes to modernize the state water system by building three new intakes in the northern Delta along with two tunnels to deliver water to the existing State Water Project aqueduct system in the southern Delta.

“In joining this effort, we bring considerable strengths and expertise to the project,” Kightlinger said. “Metropolitan has a long history of completing large capital projects on time and on budget, including our own Diamond Valley Lake in southwest Riverside County, which provides off-stream storage similar to what is proposed at Sites.”

The board action authorizes Metropolitan to enter into a project agreement with the Sites Project Authority — comprised mainly of Northern California public water agencies — for participation in the reservoir’s planning process. Metropolitan becomes the 32nd agency to join a committee of water agencies from throughout the state in funding the initial project planning phase, including nine other State Water Project contractors.

Sites Reservoir would be the latest addition to the capacity of Metropolitan’s reserve accounts, which now tops 5 million acre-feet. Metropolitan has made water storage a priority as a tool for managing drought cycles and the impacts of climate change. Over the past 25 years, Southern California has increased by 14 times the amount of water it can store in surface water reservoirs and groundwater basins in Southern California, the Central Valley and along the Colorado River system.

More information about the Site Reservoir project is available at https://www.sitesproject.org.