California’s torrential storms from late December through early January will allow the State Water Project to deliver nearly 1.3 million acre-feet of water throughout the state this year – six times as much as projected before the storms, state water officials said.
Entrenched in a third consecutive year of severe drought conditions, the California Department of Water Resources on Dec. 1 announced it would be able to deliver only 5% of water supply requested for 2023. The State Water Project stores and delivers water to 29 water agencies that serve 27 million Californians.
But now, the state says the project can deliver 30% this year. That works out to 1.27 million acre-feet of water, about 413 billion gallons.
“The allocation increase is the direct result of extreme weather in late December and nine atmospheric rivers in early January that helped fill reservoirs and dramatically increase the Sierra Nevada snowpack,” the California Department of Water Resources wrote in a Thursday news release.
A series of nine atmospheric river storms struck California between late December and the first half of January. The storms produced dangerous flooding, killing at least 22 people, and brought extreme winds causing extensive damage and cutting power to hundreds of thousands.
But the downpours and heavy mountain snow also replenished withered reservoirs and boosted California’s snowpack levels past double their historic averages for this time of year.
The allocation increase is “largely derived from improvements to reservoir supplies,” Karla Nemeth, director of the Department of Water Resources, said during a virtual news conference Thursday afternoon.
California’s two largest reservoirs included in the State Water Project, Lake Oroville and the San Luis Reservoir, gained a combined 1.62 million acre-feet of water during the recent storms, state water officials said in Thursday’s news release, which is “roughly enough to provide water to 5.6 million households for a year.”
Nemeth said the state is not yet taking snowpack calculations into consideration in State Water Project allocations, but will begin to do so following California’s next snow survey, which is scheduled for Wednesday and will represent the state’s first monthly snowpack report since the bulk of the winter storms.
Lake Oroville as of Thursday morning stood at 110% of its average water level for the date, state water officials reported.
Snowpack across the Sierra Nevada range as of Thursday was 216% of normal, according to the Department of Water Resources.
“These storms made clear the importance of our efforts to modernize our existing water infrastructure for an era of intensified drought and flood,” Nemeth said in a prepared statement. “Given these dramatic swings, these storm flows are badly needed to refill groundwater basins and support recycled water plants.”
Initial State Water Project are set each year on Dec. 1, then updated monthly through May or June. The state in December 2021 set an initial allocation of 0%, which ultimately increased to 5% for the year.
A 30% allocation represents about half of the historic average for the project, said Ted Craddock, deputy director of the State Water Project. The state last allocated 30% in 2019.
“We are not out of drought in California, but this certainly makes a significant dent,” Nemeth said Thursday, noting that the state in recent years has experienced “weather whiplash” between extreme dry and extreme wet conditions.
Nemeth called the 30% allocation “fairly conservative,” saying it takes into account the possibility of drier-than-normal conditions in the coming weeks and months.
“We are cautiously optimistic with this 30%.”
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