As winter storms continue to fill reservoirs and boost the snowpack, the Department of Water Resources (DWR) increased its estimate of this year’s State Water Project (SWP) supply from 45 to 60% of most requests.
“Our water supply outlook is definitely brighter, but we still haven’t shaken off the effects of our historic drought,” said DWR Acting Director William Croyle. “Californians in some areas still depend on bottled drinking water, some reservoirs remain low and groundwater basins are still in decline and have yet to recover. We know from painful history that California winters can go quickly from very wet to very dry. We want to see the snowpack continue to build for the remainder of the wet season.”
DWR initially estimated it would be able to deliver only 20% of the 4.1 million acre-feet of SWP water requested this year. That projection (allocation) was increased to 45% as reservoirs rose from December storms. The increase to 60% of collective delivery requests is due to the atmospheric river storms that have filled many reservoirs and brought flood waters to some areas. With more rain and snow in the forecast, DWR hopes it will be able to increase the allocation further.
Shasta Lake north of Redding, California’s and the federal Central Valley Project’s (CVP) largest reservoir, was holding 3,640,765 acre-feet, 80% of its 4.5 million acre-foot capacity and 123% of its historical average. San Luis Reservoir, a critical south-of-Delta pool for both the SWP and CVP, was holding 1,480,803 acre feet, 73% of its 2 million acre-foot capacity and 98% of its historical average for the date.
As State Water Project allocations change, it is important to remember that nearly all areas served by the project also have other sources of water, among them streams, groundwater and local reservoirs.
DWR’s California Data Exchange Center websites show current water conditions at the state’s largest reservoirs and weather stations.