The first manual snow survey of the Sierra snowpack this winter found more snow than last year at this time, but the snow water equivalent as measured statewide remains far below average for this date.
The Department of Water Resources (DWR) conducted the recent survey about 90 miles east of Sacramento on a plot along Highway 50 near Echo Summit. Snow covered the ground there to a depth of 21.3 inches, according to DWRs Frank Gehrke, chief of the California Cooperative Snow Surveys Program who conducted the survey.
The snow water equivalent was four inches at that particular snow course, or 33 percent of average. Statewide, 105 electronic sensors in the Sierra detected a snow water equivalent of 4.8 inches, 50% of the multi-year average for December 30. That compares favorably with last Winter’s first survey, when the snow water equivalent statewide was only 20% of normal, which tied with 2012 as the driest readings on record.
DWR Director Mark Cowin said of the survey results: “Although this year’s survey shows a deeper snowpack than last year, California needs much more rain and snow than we’ve experienced over the past two years to end the drought in 2015. The department encourages Californians to continue their water conservation practices.”
Cowin said the state’s surface and groundwater reservoirs have been severely depleted during the drought, which now is in its fourth consecutive year. He said a snowpack built up significantly during the winter months would be needed to recharge the reservoirs to their historical averages as the snow melts during the late spring and summer months.
Generally, California’s snowpack supplies about a third of the water needed by the state’s residents, agriculture and industry as it melts in the late spring and summer. Electronic readings indicate that water content in the northern mountains is 57% of normal for the date and 17% of the average on April 1, when the snowpack normally is at its peak before the spring melt. Electronic readings in the central Sierra show 45% of normal for the date and 16% of the April 1 average. The numbers for the southern Sierra are 48% of average for the date and 15% of the April 1 average.
DWR and cooperating agencies conduct manual snow surveys around the first of the month from January to May. The manual measurements supplement and check the accuracy of real-time electronic readings.
DWR currently estimates it will be able to deliver only 10% of the slightly more than 4 million acre feet of State Water Project (SWP) water requested for calendar year 2015 by the 29 public agencies that collectively supply more than 25 million Californians and nearly a million acres of irrigated farmland. It is hoped the initial 10% delivery estimate will increase as winter storms develop.
The final SWP allocation for calendar year 2014 was 5% of the slightly more than 4 million acre feet requested. In 2013, it was 35%, and in 2012, the final allocation was 65%. It was 80% in 2011, up dramatically from an initial allocation of 25%. The final allocation was 50% in 2010, 40% in 2009, 35% in 2008, and 60% in 2007. The last 100% allocation – difficult to achieve even in wet years because of Delta pumping restrictions to protect threatened and endangered fish – was in 2006.
DWR weather watchers note that it’s early in the season with plenty of time for the snowpack to build. The concern, however, is that irrigation-dependent San Joaquin Valley farms and some other areas will be hard hit if Water Year 2015 ends as the fourth full year of drought. Storage in key reservoirs has increased due to heavy December rainfall but is still far below normal levels for the date.
Continuing dry weather prompted Director Cowin on December 13, 2013 to mobilize DWRs drought management team “to offset potentially devastating impacts to citizen health, well-being and our economy.”
Governor Edmund G. Brown Jr. declared a drought emergency on January 17, 2014.
Last October, DWR announced the award of more than $200 million in grants to reduce drought impacts on local communities and improve access to water supplies.
California State Department of Water Resources