After storms, California boosts water allocation

California’s water authorities, which serve 27 million people, will see an increased allocation of supplies from the state after a series of winter storms increased reservoirs and snow cover, officials announced Thursday.

Less than two months after the Department of Water Resources announced it could only provide 5% of requested supplies to the 29 agencies that rely on the state water project in 2023, the Department increased its allocation to 30%. The State Water Project is a complex system of reservoirs, canals and dams that is a vital component of California’s water system.

Officials said the allocation could change over the remainder of the rainy season. But the news marks a significant turning point for California, which has been suffering from extreme drought conditions for more than three years. The final allocation last year was only 5%, and the state has not made an allocation of 30% or more since 2019.

“We are pleased that we can now increase the allocation and make more water available to local water authorities,” DWR Director Karla Nemeth said in a statement. “These storms have highlighted the importance of our efforts to modernize our existing water infrastructure for an era of increased drought and flooding. Given these dramatic fluctuations, these storm surges are badly needed to replenish aquifers and support recycled water facilities.”

The storms came as a surprise after officials warned residents to brace for another dry winter caused by La Niña, a tropical Pacific climate pattern often associated with dry conditions in California.

Instead, a series of nine powerful atmospheric rivers flooded the state, causing flooding and landslides but also increasing reservoir and snow cover. On Thursday, the nationwide snowpack was 216% of the usual value for the date.

The state’s largest reservoirs also recovered somewhat from the drought, with Lake Shasta and Lake Oroville at 55% and 63% utilization as of Thursday — up from 32% and 30%, respectively, just a month ago, state data showed.

The reservoirs have stored a total of 1.62 million acre-feet of water as a direct result of the winter storms, or about enough to power 5.6 million homes for a year, according to the DWR.

The increased allocation will relieve many agencies, including Southern California’s massive Metropolitan Water District, which supplies the Los Angeles Department of Water and Energy and 25 other agencies in the region. The MWD declared a drought emergency in December and warned that its entire service area could face forced cuts if conditions don’t improve.

“Depleted state reservoirs are beginning to recover from record lows and this increased allocation will certainly also help communities hardest hit by this drought to recover,” MWD Director-General Adel Hagekhalil said in a statement on Thursday.

“But make no mistake, while the recent storms will help alleviate the acute emergency in areas dependent on State Water Project supplies, Southern California’s water problems are far from over,” he said. “We continue to mine our largest local reservoir, Diamond Valley Lake, to meet demand.”

In fact, officials warned that California’s rainy season is still two months away and dry conditions could return. The latest seasonal forecasts from the National Weather Service’s Climate Prediction Center show that most parts of California will be equally likely to be wet or dry through April. Southern California outlook leans towards drought.

Surface water conditions aren’t the only metric factored into California’s drought, either. Groundwater — or the state’s system of underground aquifers — takes more than a handful of storms to replenish itself, especially after years of sustained overpumping.

Additionally, Southern California’s other major water source, the Colorado River, did not benefit from the atmospheric flow storms. The river is an aquatic lifeline for 40 million people in the West, but climate change and overexploitation have pushed it to breaking point.

“Southern California may see significant reductions in this supply starting next year,” Hagekhalil said, referring to the Colorado River.

Though it’s been more than three years since the state has issued an allocation of 30% or more, the number is still only about half the average allocation, said Ted Craddock, deputy director of the DWR. It has been nearly two decades since the Department issued a 100 percent allocation in April 2006.

Nemeth said that’s partly because the state’s hydrology is shifting and because climate change-induced aridification is depleting more of California’s water.

“As temperatures rise, more precipitation will evaporate into warmer air and seep into drier soil,” she told reporters.

But it’s also a case for improving the state’s aging water storage and containment infrastructure through projects like the Sites Reservoir and the proposed Delta Conveyance System, Nemeth said. The conveyor system — a controversial tunnel beneath the Sacramento-San Joaquin River Delta — would have helped capture an additional 202,000 acres of water during recent storms, she said.

Water managers will monitor how the rest of the rainy season unfolds to see if further action may be needed later in the winter, the DWR said. These include additional snow surveys and observation flights over the Sierra Nevada, which will provide better measurements of snow water content and could result in an even larger allocation.

However, it is still too early to consider lifting the nationwide drought emergency declared by Gov. Gavin Newsom in 2021, which “will remain in effect until we get a better picture of whether this year is proving to be a very wet year.” turns out or just an average year,” Nemeth said.

However, there’s no denying that the storms have made a difference. The latest update from the US Drought Monitor shows that all of California has exited its two worst categories – extraordinary and extreme drought. Just three months ago, 43% of the state fell under this classification.