SAN FRANCISCO — Welcome drifts of fresh snow awaited California’s water managers on their late-winter survey of the vital Sierra Nevada snowpack Monday after a massive winter storm slowed the state’s plunge back into drought.
The storm piled up to 8 feet (2.4 meters) of new snow in the mountains from late last week through the weekend, forcing Department of Water Resources officials to postpone the measurement for a few days.
“We didn’t feel like it would be safe” for water officials and news crews who turn out for the monthly winter assessments of Sierra snowpack to make the trek during last week’s storm, said Chris Orrock, a spokesman for state water officials.
The storm also brought parts of California more rain in hours than they received during all of February, typically one of the wettest months of the year. In Southern California, the storm brought what was only the second significant rainfall of the past year to some areas, temporarily prompting new evacuations as a precaution after rains earlier this year triggered deadly mudslides.
Most importantly, it brought copious snow to the Sierra. Runoff from melted snow through the spring historically supplies Californians with one-third of their water, although scientists say climate change is altering that.
Before the storm, California had accumulated less than a quarter of its normal snowpack for the year. It would take six more storms to bring the state up to its normal winter precipitation by April. The odds of that happening are about one-in-50, the National Weather Service cautioned.
California emerged only last year from a historic five-year drought that forced mandatory water conservation for cities and towns, dried wells, and killed millions of trees in a devastating period for wildlife.
Near-record rain last year snapped the drought, only to have this winter’s rainy season land as a dud. By February, nearly half the state — all of it in Southern California, home to more than half of residents — was back in drought, according to the U.S. Drought Monitor.
The Los Angeles-based Metropolitan Water District, the country’s largest urban supplier of water, still plans to vote in April on increased funding for conservation programs, spokeswoman Rebecca Kimitch said.
“One storm isn’t going to ... make up for what has been a very dry few months,” Kimitch said.
California’s rainy season is often this kind of a cliffhanger, Daniel Swain, a climate scientist at the University of California, Los Angeles, said last month.
The state is dependent on a handful of significant storms for its water, so things can turn around quickly, he said.
California’s reservoirs are at 106 percent of their historical average for this point in the year thanks to last year’s rains, Orrock said.
While the heavy snows in the Sierra Nevada are the main gift from the latest storm, it helps that arid Southern California got doused as well, Orrock said. Southern California rain means reservoirs there get filled, and vital below-ground natural reservoirs depleted during the drought are replenished.
He repeated the rainy-season battle cry of California water officials, whose efforts this year to mandate that lawn-loving residents turn off their automatic sprinklers when it rains have been stalled by protests from water agencies.
The rain “is going to turn their lawns green,” Orrock said. “We don’t need to have our sprinklers on.”