The state’s two major water supply managers has announced widely different early-year estimates of how much water their systems will provide this year.
While the U.S. Bureau of Reclamation estimates that most cities and farms will receive anywhere from between 65 percent and 100 percent of requested water amounts, the California Department of Water Resources estimate came in at just 15 percent.
While the state number appears low, it’s five percent more than its last estimate from December 2023 and doesn’t include snow or rainfall totals after Feb. 1.
“We will continue to assess our State Water Project allocation forecast as more storms materialize in February and March,” DWR Director Karla Nemeth said in a news release Wednesday. “This season is an important reminder of our extreme conditions and shift to bigger, flashier storms and the need to continue increasing the state’s ability to capture and store stormwater when it comes as rain instead of snow.”
This season is an important reminder of our extreme conditions and shift to bigger, flashier storms and the need to continue increasing the state’s ability to capture and store stormwater when it comes as rain instead of snow.
DWR Director Karla Nemeth
A major factor in the differences between the federal and state allocation numbers is that all the higher delivery estimates from the Bureau of Reclamation are for water users north of the Sacramento-San Joaquin River Delta, where the bulk of the state’s rain and snow accumulates.
“There is a very large difference in the Central Valley project and the State Water Project in that we have a significant number of water supply contractors that are north of the Delta,” said Bureau of Reclamation Deputy Regional Director Kristin White.
White said the federal system’s south-of-Delta water users — while fewer than those that rely on the state system — will largely receive allocations similar to the state system’s.
DWR runs the State Water Project, which delivers water to 29 public agencies serving 27 million people and 750,000 acres of farmland.
FIRST: Part of the State Water Project (SWP), the Clifton Court Forebay serves as ground zero for the starting point of the California Aqueduct, which delivers water to Southern California. (Photo courtesy California Department of Water Resources) LAST: The Mokelumne River flows into the Sacramento River near Walnut Grove in the Northern Delta, one of the key components that help make up the Central Valley Project. (Photo courtesy of Water Education Foundation)
The Central Valley Project, operated by the Bureau of Reclamation, delivers water to wholesalers and retailers in 29 of the state’s 58 counties, including five million acre-feet to farms and 600,000 acre-feet — a year’s supply for roughly 2.5 million people — to cities and towns.
“The wet hydrologic conditions we experienced during the 2023 water year left most of our reservoirs in good shape as we progressed to the 2024 water year,” said Bureau of Reclamation Regional Director Karl Stock.
Stock said that precipitation levels since October, the start of the “water year,” were initially unimpressive but have rebounded somewhat.
“Since that time, several storms have boosted the Sierra Nevada snowpack, bringing us to near normal conditions for Northern California. It is likely we will see the water supply benefits from these storms in the March 1 forecast update,” he said.
According to DWR estimates, statewide snowpack is currently at 86 percent of average, and is 69 percent of the April 1 average, which is considered the peak snowpack measurement date and the start of the spring runoff.
Also, most major reservoirs are at or above their average water storage levels, including Oroville at 134 percent of average, Shasta at 124 percent, New Melones at 139 percent, San Louis at 84 percent and Sonoma at 115 percent, according to data posted on the DWR website.
Optimistic outlook for Bay Area water supply
Some Bay Area water managers were pleased that the state numbers increased at least a bit from December.
“The Alameda County Water District is encouraged by the allocation increase from 10 percent to 15 percent from the Department of Water Resources for agencies like ACWD that rely on the State Water Project,” district officials said in an email Wednesday.
“The (State Water Project) is a critical water supply in California and an important part of ACWD’s diverse portfolio, and this increase in supply allocation will help as we carefully plan and optimize our water supplies for 2024 and beyond,” according to the district, which serves 345,000 people in Fremont, Newark and Union City.
