California snowpack begins season with 50% of average water content

California’s Department of Water Resources (DWR) has completed the first snow survey of the season at Phillips Station, providing an early snapshot of conditions that will influence runoff, reservoir operations, and downstream stormwater management this year.

The manual survey measured 24 inches of snow depth and a snow water equivalent (SWE) of 5 inches, or 50% of average for the location. Statewide, the snowpack SWE is 71% of average for this date, according to DWR’s electronic network of 130 monitoring stations across the Sierra Nevada.

“The dry conditions and warmer temperatures in early December delayed our snow-building season, but the return of storm activity, especially in the last week, helped to build a solid base for this year’s snowpack,” said Angelique Fabbiani-Leon, state hydrometeorologist for DWR, in a press release. “While California is in a better position now, it is still early in the season and our state’s water supply for this year will ultimately depend on a continued cadence of storms throughout winter and early spring.”

For stormwater and water resource professionals, the survey highlights ongoing climate variability, with sharp swings between dry and wet conditions becoming more common. On average, January through March produce the bulk of Sierra snow, which ultimately supplies about 30% of California’s annual water needs.

“It’s great to see so much fresh snow in the Sierra following a relatively dry December,” said DWR Director Karla Nemeth in a press release. “More than any other factor, the rain and snow that falls in these critical winter months dictates how much water can be delivered to Californians and farmland statewide.”

DWR will conduct additional snow surveys monthly through spring, with the next survey scheduled for early February.