Series of atmospheric rivers provided significant snowpack gains, boosted water supply statewide
Press release from the Department of Water Resources
The Department of Water Resources (DWR) today conducted the first snow survey of the season at Phillips Station. The manual survey recorded 24 inches of snow depth and a snow water equivalent of 5 inches, which is 50 percent of average for this location. The snow water equivalent measures the amount of water contained in the snowpack and is a key component of DWR’s water supply forecast. Statewide, the snowpack is 71 percent of average for this date.
Today’s results are welcome news for water managers who rely on the statewide snow surveys to make water supply decisions for the year ahead. California’s statewide snowpack had been lacking in early December with above-average temperatures and very little storm activity. Recent storms have turned that around and provided a significant boost to the snowpack and the state’s water supply.
“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 Hydrometerologist for DWR. “Thankfully, the recent storms that reached the state were cold enough to provide necessary benefits for the snowpack and our water supply. 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.”
DWR’s electronic readings from 130 stations placed throughout the Sierra Nevada indicate that the statewide snowpack’s snow water equivalent is 6.5 inches, or 71 percent of average for this date, compared to 115 percent on this date last year.
On average, the largest snow-producing months in the Sierra Nevada are January, February, and March. Drought and flood always marked the California climate, but extreme whiplash between wet and dry is becoming more pronounced, not just year to year but often within the same season or month.
“It’s great to see so much fresh snow in the Sierra following a relatively dry December,” said DWR Director Karla Nemeth. “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. We make the most of what Mother Nature delivers with advance planning that enables Forecast Informed Reservoir Operations and groundwater recharge.”
Major reservoirs statewide are currently 123 percent of average thanks to recent precipitation on top of three consecutive years of above-average snowpack conditions.
On average, the Sierra snowpack supplies about 30 percent of California’s water needs. Its natural ability to store water is why the Sierra snowpack is often referred to as California’s “frozen reservoir.” Data from these snow surveys and forecasts produced by DWR’s Snow Surveys and Water Supply Forecasting Unit are key factors in determining how DWR manages the state’s water resources.
DWR conducts four media-oriented snow surveys at Phillips Station each winter near the first of each month, January through April and, if necessary, May. The next survey is tentatively scheduled for February 3.
For California’s current hydrological conditions, visit https://cww.water.ca.gov.
