Sierra snowpack at 66% of April 1 average; Statewide it is 53% of average

SACRAMENTO, Calif. – The precipitation of March did not do enough to boost the snowpack in the Sierra to high figures, but it did give surveyors better figures than the 47 percent of average one month ago. The manual measurement of the snowpack at Phillips Station near Sierra-at-Tahoe showed the snow depth was 43.5 inches with a snow water equivalent (SWE) of 16.5 inches. This is 66 percent of the April 1 average at that location southwest of Lake Tahoe.

The Department of Water Resources (DWR) survey at Phillips Station was their fourth manual snow survey of 2020 and not done before a large gathering of media as they normally due, because of the ongoing COVID-19 pandemic.

The SWE measures the amount of water contained in the snowpack, which provides a more accurate forecast of spring runoff. Measurements from the 130 electronic snow sensors, scattered throughout the state, indicate that the statewide snowpack’s water equivalent is 15.2 inches, or 53 percent of the April average.

In addition to the manual snow surveys and automated snow measuring sites, DWR is collaborating to augment the measurements with satellite and air-borne remote-sensed data. These experimental data products provide additional detail to the spatial patterns of snow water accumulation in the watersheds that helps inform and guide forecast runoff quantities and timing. Such data gathering will be a key adaptation strategy as climate change impacts continue to mount.

“While today’s survey results show our snowpack is better off than it was just last month, they still underscore the need for widespread, wise use of our water supplies,” said DWR Director Karla Nemeth. “California’s climate continues to show extreme unpredictability, and February’s record dryness is a clear example of the extremes associated with climate change.”

California is experiencing increased extremes and variability due to climate change. In one year, California has gone from having the fifth best-recorded snowpack to one of the 10 worst.

“Over the last decade, California’s snowpack has been alternating between extremely wet and extremely dry,” stated Sean de Guzman, chief of DWR’s Snow Survey and Water Supply Forecast Section. “In the past 10 years, we’ve seen three of our smallest snowpacks on record, but we’ve also seen three of our largest snowpacks on record.”

On average, the snowpack supplies about 30 percent of California’s water needs as it melts in the spring and early summer.

The state’s six largest reservoirs currently hold between 82 percent (San Luis) and 125 percent (Melones) of their historical averages for this date. Lake Shasta, California’s largest surface reservoir, is 98 percent of its historical average and sits at 79 percent of capacity.