A spring evening over the California Aqueduct in the San Joaquin Valley.
Credit: DWR

December 2, 2020 - SACRAMENTO, Calif. – With California off to a dry start for the water year, the California Department of Water Resources (DWR) on Tuesday announced an initial State Water Project (SWP) allocation of 10 percent of requested supplies for the 2021 water year.

Initial allocations are based on conservative assumptions regarding hydrology and factors such as reservoir storage. Allocations are reviewed monthly and may change based on snowpack and runoff information. They are typically finalized by May.

“While we still have several months ahead of us, dry conditions persist,” said DWR Director Karla Nemeth. “As communities throughout California prepare to support their environment and economies through times of extended dry periods, state agencies plan together to support those communities. Californians can help by always using water carefully, inside and outside their homes and businesses.”

DWR’s eight precipitation stations in Northern California recorded a record-low zero percent of average rainfall in October and 53 percent in November.

Most of the state’s major reservoirs are lower than historical average to date compared to a year ago. Lake Shasta, the federal Central Valley Project’s (CVP) largest reservoir, is at 75 percent compared to 119 percent its historical average to date in 2019. Lake Oroville, the SWP’s largest reservoir, holds 61 percent compared to 90 percent of its historical average to date in 2019. San Luis Reservoir, a joint-use facility for the SWP and CVP, now holds 76 percent compared to 72 percent of its historical average to date in 2019.

The­­ 10 ­­­­percent initial allocation amounts to 422,848 acre-feet of water, distributed among the 29 long-term SWP contractors who serve more than 27 million Californians and 750,000 acres of farmland.

Last year’s initial allocation was 10 percent, with a final allocation of 20 percent set in May.

Nearly all areas served by the SWP have sources of water other than the SWP allocation, such as streams, groundwater, and local reservoirs.

DWR will conduct the season’s first snow survey at Phillips Station in the Sierra Nevada on December 30, 2020. On average, the snowpack supplies about 30 percent of California’s water needs as it melts in the spring and early summer.

For information on current water conditions at the state’s largest reservoirs and weather stations, visit the California Data Exchange Center website.
Source: DWR