On Tuesday, the California Department of Water Resources announced a further increase in the State Water Project, or SWP, water supply allocation forecast for 2024.
The forecasted allocation has increased to 40%, up from 30% last month.
The State Water Project provides critical water supplies to 27 million Californians and farmers served by 29 public water agencies.
Tuesday’s increase would provide an additional 420,000 acre-feet of water, enough water to serve an estimated 1.5 million households for a year.
The allocation update is based on an 800,000 acre-foot increase in storage at Lake Oroville and the latest snow survey data from the all-important April 1 measurements. April 1 is typically when California sees peak snowpack and the start of the snowmelt season.
Statewide, the snowpack remains near average at 99 percent of average for this date. The spring forecast in the latest snow runoff report, known as Bulletin 120, also anticipates above average runoff this spring.
The State Water Project is working with the U.S. Army Corp of Engineers to manage flood releases and maximize the capture and storage of water from the winter storms and spring runoff in its reservoirs. Since Jan. 1, storage has increased by 917,000 acre-feet at Lake Oroville and by 178,125 acre-feet at San Luis Reservoir. Oroville is currently at 124 percent of average and 94 percent of capacity and is expected to reach capacity next month.
During the spring, the ability to move water supply south through the system will continue to be impacted by the presence of threatened and endangered fish species near the State Water Project pumping facility 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. This reduction in pumping has limited the ability to move and store water into San Luis Reservoir. This reduced pumping is expected to continue into late spring.
The State Water Project anticipates increasing its pumping significantly this summer as soon as the fishery conditions and our State and federal operating permits allow.
“This year highlights 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,” said DWR Director Karla Nemeth. “We need to be moving water when it’s wet so that we can ease conditions for people and fish when dry conditions return. It’s one more reason the Delta Conveyance Project, which would move water when the flows are high in a manner safer for fish, is a necessary climate adaptation project for California.”
Had the Delta Conveyance Project been in place this winter, the State Water Project would have been able to capture an additional 909,000 acre-feet of water since January 1. That’s enough water for 9.5 million people, or 3.1 million households, for a year.
The updated State Water Project allocation forecast announced Tuesday anticipates delivery of 40 percent of requested supplies to contractors south of the Delta, which accounts for the majority of contractors; 65 percent of requested supplies to contractors north of the Delta; and 100 percent allocation to Feather River Settlement Contractors.
Allocations are updated monthly as snowpack, rainfall, and runoff information is assessed, with a final allocation typically determined in May or June.
“While we are glad to see this modest allocation increase for public water agencies who rely on SWP supplies, it is still far below the amount of water we need,” said Jennifer Pierre, general manager of the State Water Contractors, a nonprofit association of 27 public agencies from Northern, Central and Southern California that purchase water under contract from the California State Water Project.
“Water deliveries should be far higher in a good water year like we've had — there is a lot of water in the system, California reservoirs are full, and runoff from snowpack melt is still to come. 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,” Pierre said.
Pierre said that, earlier this year, water operators reduced the amount of water they could divert from the Delta to protect endangered salmon and steelhead near the pumps. In a year with great hydrology, the unprecedented and significant export restrictions between January and March cost over a million acre-feet of water supply for the SWP, likely hampering our readiness for the next drought.
In addition, Pierre said that had the Delta Conveyance Project been operational this year, it could have captured and moved about 909,000 acre-feet of water between Jan. 1 and April 4 while keeping endangered species safe. That’s enough water to supply about 9.5 million people, or 3.1 million households — 35% of the SWP’s service population — for an entire year.
“While the presence of these fish hampered our ability to move and capture water for the entire winter and early spring season, it is important to note that water operators were able to protect many of them despite reports to the contrary. Most winter-run Chinook salmon and Central Valley steelhead categorized as captured or ‘taken’ at the pumps survive, are transported downstream, and then released to continue migrating to the Pacific Ocean,” Pierre said.
Pierre said scientific research indicates that salmon and steelhead salvaged at the pumps and released downstream are more likely to survive as they travel to the ocean than those that approach intake facilities but are not entrained. While there is a lot of evidence that salmonids this year experienced good survival conditions, there is no evidence that the significant salvage experienced this year had any meaningful effect on the salmonid population.
Protecting species is critically important, as is ensuring the 27 million people, 750,000 acres of farmland and countless businesses who rely on SWP supplies continue to receive affordable, high-quality water required to live and work, Pierre said.
“Infrastructure like the Delta Conveyance Project and updated regulatory rules like the Agreements to Support Healthy Rivers and Landscapes will allow us to better manage our water supplies for both people and fish. We must upgrade our decades-old infrastructure to keep pace with California’s rapidly changing climate and modify our regulations to reflect the best available science to ensure we can move excess flows efficiently with minimal impact on fish and capture precipitation when we get it for use when we don’t,” Pierre said.
California Department of Water Resources updates allocation of State Water Project supplies for 2024
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