Surveyors plunged a pole into the Sierra Nevada snowpack on Tuesday and took the first manual measurement of the wet season, finding water content was about half of normal as California flirts with a possible sixth year of drought.
Surveyors took the reading at 6,000 feet near Lake Tahoe as major cold and windy storms were expected to dump four to five feet of snow through Thursday in areas above 4,500 feet in Northern and central California, while mountain areas below that could get two to three feet, forecasters said.
The storms were expected to boost the snowpack that provides roughly a third of California's water in normal years for drinking, farming and wildlife when it melts in warm, dry months.
December was unusually wet in the Sierra Nevada, but warm temperatures meant that much of that precipitation fell as rain rather than snow. Columbia University climatologist Park Williams has observed this trend over the past 30 years in California.
“Even though we’ve been getting the same amount of precipitation over the long term, less of that precipitation is falling as snow. And that that does fall as snow is tending to melt earlier,” he said.
Indeed, readings taking throughout the Sierra in early January showed the overall snowpack to be 30 percent below average water content.
At Tuesday's reading at Phillips Station, the water content measured at 53 percent of normal, said Frank Gehrke, chief snow surveyor at the state Department of Water Resources.
Despite the lower water-content level, he called it a good start because higher elevations were doing better. He also took the survey at an elevation below the snowline for December's storms.
A year ago, the snowpack was slightly above normal levels, but Gehrke recalled that the rain and snow essentially stopped in February and March, leaving the state at a nearly average year for precipitation on April 1.
"This year, it looks like (storms are) lined up off the coast and will continue to increase the snowpack," Gehrke said as he stood on about three feet of snow.
Water managers prefer snow to rain because snowmelt trickles into reservoirs throughout the late spring and summer, when precipitation has stopped falling in California. Rain, meanwhile, gushes downhill in a torrent during the winter, when it is less needed. The sudden flows are also harder to capture in reservoirs, forcing water managers to empty excess water down spillways to avoid flooding.
“The current system is more suited to handle snowpack,” said Bob Muir, spokesman for the Metropolitan Water District, which procures water for 19 million Southern Californians. The State Water Project “is not flexible enough to handle large rainstorm events.”
At the height of the drought in 2015, snowpack surveyors stood on a dirt patch for the April 1 measurement at Phillips Station, finding the least snow since records had been taken in 1950.
Gov. Jerry Brown responded by ordering residents statewide to use 25 percent less water. Many let their lawns turn brown — or tore them out — and flushed their toilets less often to comply.
The drought eased last year and so did regulations.
In February, the state water board will again consider the conditions and decide whether the state needs to take a stronger stand on conservation.
"If the skies dry up, we'll be looking at something different," board chair Felicia Marcus said. "We're playing this one moment to moment."
Smith reported from Fresno. Jocelyn Gecker contributed to this report from San Francisco.
This story has been updated.