DWR doubles water allocation forecast

Robert Summa, Appeal-Democrat, Marysville, Calif.
·3 min read

Mar. 22—The Department of Water Resources (DWR) on Friday said there will be a second increase in the State Water Project (SWP) allocation forecast for 2024, doubling the amount that was announced in February.

Officials said the newly announced forecasted water allocation is 30% of requested supplies, up from the 15% announced last month — the SWP is a source of water for 29 public water agencies that serve 27 million Californians.

The allocation forecast was increased after taking into consideration snow survey measurements and data up until March 1 and spring runoff forecasts. According to the most recent snow survey conducted by DWR at Phillips Station on Feb. 29, the manual survey recorded 47.5 inches of snow depth and a snow water equivalent of 18 inches, which is 77% of average for Phillips Station.

Officials said the "snow water equivalent measures the amount of water contained in the snowpack and is a key component of DWR's water supply forecast."

"DWR's electronic readings from 130 stations placed throughout the state indicate that the statewide snowpack's snow water equivalent is 18.7 inches, or 80% of average for this date, an improvement from just 28% of average on January 1," the DWR said in February. "The snowpack is currently only 70% of the critical April 1 average, when the snowpack is typically at its peak."

On April 1, DWR said it will conduct another snow survey, which could increase the allocation. Currently, officials said, the statewide snowpack is 98% of average.

Officials said the SWP has been "focused on maximizing the capture and storage of water" from recent winter storms. Since Jan. 1, water storage has increased by 630,000 acre-feet at Lake Oroville and by 150,000 acre-feet at San Luis Reservoir.

"The ability to move water south through the system has been significantly impacted by the presence of threatened and endangered fish species near the State Water Project pumping facility in the south Delta," officials said. "The presence of these fish species has triggered requirements within the State and federal permits for the operation of the State Water Project and the federal Central Valley Project that have significantly reduced pumping from the Delta."

Officials said that reduction in pumping has limited the ability to move water into the San Luis Reservoir.

"DWR continues to take proactive measures and use the best available science to operate our water storage and delivery system to balance water supply needs while protecting native fish species," DWR Director Karla Nemeth said in a statement. "As we experience more extreme weather conditions, each year brings its own challenges and that's why it's so critical to continue to adapt our water system to build climate resilience."

Officials said Friday that the state's reservoirs "remain in good shape" due to last year's strong winter storms. Across California, reservoirs are at 115% of average for this time of year, with Lake Oroville, the State Water Project's largest reservoir, at 125% of average and 86% of capacity.

As of Friday, the reservoir level at Lake Oroville was at 866 feet elevation with 10,000 cubic feet of water per second being released into the Feather River. Officials said releases may be adjusted over the weekend or early next week to account for an incoming storm. Feather River recreation users were advised to remain alert because river flows were expected to be swift and cold and could change based on weather forecasts.

The updated SWP allocation forecast announced on Friday anticipates delivery of 30% of requested supplies to contractors south of the Delta, which makes up the majority of contractors; 50% of requested supplies to contractors north of the Delta; and an anticipated 100% allocation to Feather River Settlement Contractors, officials said. Allocations are expected to be updated each month as snowpack, rainfall, and runoff information is assessed, with a "final allocation typically determined in May or June following the April snow survey. The next possible allocation update would be in April," the DWR said.