With runoff from this year’s snow and rain boosting the levels of California’s reservoirs, state water managers on Tuesday announced plans to increase deliveries of supplies from the State Water Project to 40% of full allotments, up from 30% last month.
The increased allocation, which had been widely expected, means that suppliers serving 27 million Californians, as well as some farming areas, will have substantially more water available to use and store this year. But the Department of Water Resources also said officials have had to limit pumping from the Sacramento-San Joaquin River Delta this year because of environmental protections for native fish.
Although this year has brought average wet conditions, the agency said its ability to move water south through the system of aqueducts and reservoirs has been “impacted by the presence of threatened and endangered fish species” near the state’s pumping facilities in the south delta.
“The presence of these fish species has triggered state and federal regulations that significantly reduce the pumping from the Delta into the California Aqueduct,” John Yarbrough, acting deputy director of the State Water Project, said in a notice outlining the increased allocation.
That has limited the state’s ability to move water south to San Luis Reservoir, which stands at 72% of capacity — a level that is 86% of average for this time of year.
The reduced pumping is expected to continue into late spring, Yarbrough said. State officials then expect to increase pumping significantly this summer, once conditions allow for it under the pumping facilities’ permits.
Environmental and fishing groups have criticized a recent rise in the estimated numbers of fish that have died at the pumping facilities in the delta, and have demanded that state and federal agencies take steps to limit the losses of threatened steelhead trout and endangered winter-run chinook salmon.
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The massive pumps that draw water into the State Water Project and the federally managed Central Valley Project are strong enough that they can reverse the flow in parts of the south delta.
The losses of fish are estimated based on how many fish are collected at a state facility near the pumps and trucked to nearby areas of the delta, where they are released. The calculations attempt to account for fish that are caught by predators and those that are killed when they are sucked into pumps.
Environmental groups are urging water managers to scale back pumping until juvenile salmon and steelhead have finished migrating through the delta and into San Francisco Bay.
State water managers said they are taking various steps to limit the losses of fish. They said pumping has been reduced this month to minimal levels in order to comply with spring flow requirements.
The Department of Water Resources said the increased allocation was based on the latest snowpack and runoff data. The snowpack measures 99% of average for this time of year, and the amount of runoff is projected to be above average.
The state’s reservoirs rose dramatically in 2023, which brought one of the wettest winters on record, and this year’s storms have again boosted reservoir levels.
Lake Oroville, the state’s second largest reservoir, is now at 94% of capacity and is projected to completely fill next month.
The water that is pumped from the delta and flows south into the California Aqueduct provides a significant portion of Southern California’s supplies.
With the increased allocation, the Metropolitan Water District of Southern California will be able to meet the region’s water demands this year and will have surplus water to put into storage, said Adel Hagekhalil, the MWD’s general manager.
That will build on the record 3.4 million acre-feet of water that the district has banked in various reservoirs and underground storage areas. The MWD’s added supplies amount to about 200,000 acre-feet, enough to supply roughly 600,000 typical households for a year.
“We will make every effort to store as much water as possible in every storage account available, for use during the next dry year,” Hagekhalil said.
California has an above-average snowpack and the state’s reservoirs are mostly filled, bringing a substantial boost to water supplies.
He urged Southern Californians to keep up their efforts to save water.
“The more efficient we all are during these wet years, the more water we can keep in storage for use during the next inevitable drought to provide reliable water supplies,” he said.
The final water allocation still could change in May or June as state water managers reassess conditions.
The restrictions on pumping this year have coincided with the ongoing debate over the efforts of Gov. Gavin Newsom’s administration to advance the proposed Delta Conveyance Project, a 45-mile tunnel that would transport water beneath the delta.
Karla Nemeth, director of the Department of Water Resources, said the limitations on pumping this year underscore “the challenges of moving water in wet periods with the current pumping infrastructure in the south Delta.”
“We had both record low pumping for a wet year and high fish salvage at the pumps,” Nemeth said in a press release. “We need to be moving water when it’s wet so that we can ease conditions for people and fish when dry conditions return.”
She said in a wet year like this, the proposed tunnel would allow the state to move more water during high flows “in a manner safer for fish.”
Her department estimated that if the Delta tunnel had been in place this winter, the State Water Project would have been able to capture an additional 909,000 acre-feet of water, enough to supply roughly 3 million households for a year.
The State Water Contractors, an association of 27 public agencies that purchase the water, reiterated its support for moving forward with the Delta Conveyance Project.
“Water deliveries should be far higher in a good water year like we’ve had,” said Jennifer Pierre, the association’s general manager. “Today’s modest allocation highlights just how difficult it is to operate within current regulatory constraints and with infrastructure in need of modernization. Even in a good water year, moving water effectively and efficiently under the current regime is difficult.”
The Delta Conveyance Project is a key component of Gov. Gavin Newsom’s strategy for a hotter, drier California. Opponents say it will be an ecological disaster.
Newsom has called the Delta Conveyance Project a central piece of his administration’s strategy for making the state’s water-delivery system more resilient to the effects of climate change.
Opponents are trying to block the project in the courts. Environmental groups, fishing advocates, tribal leaders and local agencies have said the Delta Conveyance Project would harm the delta’s ecosystem and have also raised other concerns.
In one of the latest court cases, four environmental groups and the Central Delta Water Agency are seeking to challenge the state’s reliance on decades-old water rights permits for the project. They’ve argued that the State Water Resources Control Board has wrongly given preferential treatment to the state, which is seeking to use water rights that were originally filed in 1955 and 1972.
Lawyer Osha Meserve, who represents the Central Delta Water Agency, said the state water board is letting the Department of Water Resources “cut in line ahead of thousands of other water rights holders” — and ahead of flows that are necessary to keep the delta and its fish healthy.
The Department of Water Resources’ staff said they are reviewing the case and disagree with the assertions. They said in an email that water rights applications “do not expire or terminate” in the way the plaintiffs suggest, and that the state’s permits remain valid.
California Gov. Gavin Newsom has released new a plan outlining state goals for improving water management and adapting to climate change.
