The Delta–Mendota Canal spans over 116 miles from the Sacramento-San Joaquin Delta to the San Joaquin Valley
Credit: USBR
Above average precipitation and snowpack allow for an increase in planned water deliveries for 2025
December 24, 2024 - SACRAMENTO, Calif. – On Monday, the Department of Water Resources (DWR) announced an update to the State Water Project (SWP) allocation forecast for 2025. The allocation has increased to 15 percent of requested supplies, up from the initial allocation forecast of 5 percent announced earlier this month. The SWP provides water to 29 public water agencies that serve 27 million Californians.
Strong storms in late November and early December have helped boost statewide precipitation to just above average for this time of year. Reservoir levels have also increased because of the storms. The initial allocation forecast announced on December 2 had not accounted for these storms because the data was not yet available to water managers. Prior to the second half of November, the start of the water year had been dry and warm.
“The past several weeks has brought welcome rain and snow to Northern California and these improved conditions have allowed the State Water Project to increase the allocation forecast to the benefit of millions of Californians,” said DWR Director Karla Nemeth. “While we typically wait to provide an update until January, we felt it important to let our State Water Contractors know of the increase as soon as possible to allow them to better plan their water supply for the year ahead.”
State water managers will continue to monitor precipitation and snowpack conditions as well as account for dry soils that may soak up some of the spring runoff following record heat this past summer. Additionally, Southern California remains very dry and has not benefited from the atmospheric rivers experienced so far this season.
“California is still in the early months of our wet season and as recent history has shown, conditions can change quickly,” said Dr. Michael Anderson, State Climatologist. “While Northern California has benefitted from early season storms, dry conditions in the new year can leave us with below average totals when warmer weather arrives."
Each year, DWR provides SWP allocation forecasts based on available water storage, projected water supply, and water demands. Allocations are updated monthly as snowpack, rainfall, and runoff information is assessed, with a final allocation typically determined in May or June. As the winter progresses, if California sees an increase in rain and snowfall, the allocation forecast may increase. The next update will likely come in January and will use information from the first snow surveys of the season.
The allocation forecast notice to State Water Contractors and historical data on SWP allocations are available at https://water.ca.gov/programs/state-water-project/management/swp-water-contractors.
Source: CA. DWR
