Sierra Nevada snowpack just 18% of normal -- second-lowest in recorded history

Obliterated by record hot temperatures in March, the statewide Sierra Nevada snowpack, the source of one-third of California’s water supply, stood at only 18% of its historical average on Wednesday, the second-lowest April 1 reading in recorded history.

Still, water managers said Wednesday that the state won’t face drought conditions and water shortages unless next winter ends on a similarly dry note a year from now.

“We’re not in a hydrologic drought,” said Karla Nemeth, director of the State Department of Water Resources at a news conference at Phillips Station, a 6,800-foot Sierra Nevada meadow showing only sparse patches of snow. “But the supplies we have are all we have. What we save today will be a very important hedge against a dry next year.”

The only other April 1 since the beginning of modern records in 1950 when snow levels across the state’s 400-mile-long landmark mountain range were lower came in 2015, measuring then at an abysmal 5% of normal. That year, former Gov. Jerry Brown stood in the same meadow near Sierra-at-Tahoe ski area that normally would have been under 5 feet of snow and famously announced sweeping statewide water restrictions.

Back then, however, California was struggling through its third dry winter in a row. This year, the state has enjoyed three wet winters in a row, leaving reservoirs nearly full.

Scientists have predicted for years that the warming climate means the Sierra’s snowpack will melt earlier in many years than it has in decades past. This year, the big melt means higher fire risk in the Sierra over the summer and a strain on water resources, because as farms and cities draw down reservoirs, there won’t be melting snow to top them up in the months ahead.

“The good news is that most reservoirs are at or above their historic averages,” said Jeffrey Mount, a professor emeritus at UC Davis and senior fellow at the Public Policy Institute of California’s water center. “But our whole water system was designed around the mid-20th-century climate, which relies on having snowpack. And this year nature took it away.”

Bay Area officials said the lack of snow this winter is not expected to mean local water restrictions in the months ahead.

“Because of the last three years, we’re OK for this summer,” said Matt Keller, a spokesman for the Santa Clara Valley Water District, which provides drinking water and flood protection to 2 million people in Santa Clara County. “But after that, it’s wait and see.”

Keller noted that his agency has spent the past three years recharging groundwater aquifers amid regular big winter storms. Groundwater provides roughly half of the county’s water supply.

“Reservoir levels locally and statewide, and our groundwater levels, are above-normal for this time of year,” he said. “We have a little bit of water built in right now that we can use. But if we have another dry winter season next winter, come April or May next year, we could be talking about a potential drought.”

Water managers in urban areas across the state echoed similar sentiments.

Nevertheless, many were rattled by the feast-or-famine nature of this winter.

It began dry, causing many ski resorts to delay their opening days. Then, just after Christmas, two huge storms dumped nearly 10 feet of snow across the state, bringing levels near normal and saving ski season. But a high-pressure ridge came back over the West Coast, blocking storms through most of January and providing balmy summer-like weather for five weeks.

That pattern broke in mid-February with another huge atmospheric river storm, which delivered another 100 inches to the Sierra. On Feb. 20, the snowpack was 76% of normal. Then in March, an unprecedented heat wave hit the Western United States.

It broke records from the Bay Area to Denver to Phoenix, rapidly melting much of the snow that had built up across the Sierra, the Rockies, and other large mountain ranges. And although a small storm that wetted the Bay Area Tuesday was expected to bring 6 to 12 inches Tuesday night through Wednesday to the higher elevations of the Tahoe region, it was too little too late.

“We weren’t doing that great anyway,” Mount said. “But all of March was a bust. We just cooked off all the snow. Now it’s gone.”

Officials from the state Department of Water Resources conducted their monthly manual snow survey news conference at Phillips Station, off Highway 50 in El Dorado County. That location had so little snow it was considered 0% of normal, they said. The broader statewide snowpack totals Wednesday came from a network of more than 100 automatic snow sensors spread across the Sierra.

The April 1 measurements are considered the most important of the year because they traditionally mark the end of winter, when water planners have a clear idea of how much water to expect for farms and cities through the summer and fall.

Last April 1, the statewide Sierra snowpack was 96% of normal. The year before, in 2024, it was a healthy 111%. The year before that, in 2023, it was 237% — the biggest in 40 years, after a relentless series of blizzards ended California’s 2020-2022 drought and ushered in the relative water comfort the state has enjoyed over the past three years.

The rain and snow from the past three years left reservoirs on Wednesday brimming.

Shasta Lake, the state’s largest, near Redding, was 90% full. So was Oroville, in Butte County, the second largest. Farther south, San Luis Reservoir, east of Gilroy, was 89% full. Hetch Hetchy in Yosemite National Park — the main source of water for San Francisco and the Peninsula — was 93% full.

Similarly, the seven reservoirs operated by the East Bay Municipal Utility District, which provides water to 1.4 million people in Alameda and Contra Costa counties, were 85% full. The seven reservoirs operated by the Marin Municipal Water District were 98% full.

And the largest reservoir in Southern California, Diamond Valley in Riverside County, was 97% full.

To compensate for the new, hotter, dry reality, which will likely mean some farmland being permanently fallowed in areas like the San Joaquin Valley in the decades ahead, Mount said, the state needs to expand its water storage capacity to catch more rain when it comes. That means building new off-stream reservoirs, he said, raising the heights of dams at some existing ones like San Luis, and broadening projects to increase groundwater storage, recycled water, and groundwater capture, along with conservation measures like paying people to install water-efficient landscaping and buy water-efficient appliances.

“We need to do a much better job of harvesting and storing water in the wet years to get through the dry years,” Mount said.