The Department of Water Resources (DWR) will conduct this winter’s first snow survey on Jan. 3.
One center of attention will be the manual survey scheduled for 11 a.m. off Highway 50 near Echo Summit. This and other manual and electronic surveys up and down the state will determine the amount of water in the early winter snowpack.
Statewide electronic readings indicate that today’s snowpack water content – near the end of an unusually dry December – is only 24 percent of normal for the date. At this time last year (Dec. 27), the statewide snowpack water content was 202 percent of average.
Despite the low early readings, the snowpack and its water content can be expected to increase through the winter months to April 1, when melting snow begins flowing into streams and reservoirs.
“Thanks to good reservoir storage left over from last winter’s storms, we anticipate an adequate water supply next summer,” said DWR Director Mark Cowin. “Our initial estimate is that we’ll be able to deliver 60 percent of the slightly more than 4 million acre-feet of water requested from the State Water Project, and we hope to increase the percentage as winter storms develop.”
The initial delivery estimate for this calendar year was only 25 percent of the slightly more than 4 million acre-feet requested by the 29 public agencies that distribute State Water Project (SWP) water to 25 million Californians and nearly a million acres of irrigated farmland. As winter took hold, a near-record snowpack and heavy rains sweeping the state resulted in deliveries of 80 percent of requests in 2011. The final allocation was 50 percent in 2010, 40 percent in 2009, 35 percent in 2008, and 60 percent 2007. The last 100 percent allocation – difficult to achieve even in wet years because of Delta pumping restrictions to protect threatened and endangered fish – was in 2006.
DWR and cooperating agencies conduct manual snow surveys around the first of the month from January to May. The manual surveys supplement and check the accuracy of real-time electronic readings as the snowpack builds then melts in spring and summer.
Most of the state’s major reservoirs are above normal storage for the date.
Lake Oroville in Butte County, the State Water Project’s principal storage reservoir, is at 115 percent of average for the date (72 percent of its 3.5 million acre-foot capacity). Lake Shasta north of Redding, the federal Central Valley Project’s (CVP) largest reservoir with a capacity of 4.5 million acre-feet, is 108 percent of average for the date (68 percent of capacity). San Luis Reservoir in Merced County, an important storage reservoir south of the Delta, is at 139 percent of average for the date (94 percent of capacity). San Luis, with a capacity of 2,027,840 acre-feet, is a critically important source of water for both the SWP and the CVP when pumping from the Delta is restricted or interrupted.
(An acre-foot is 325,851 gallons, enough to cover 1 acre to a depth of 1 foot.)
The mountain snowpack that melts into reservoirs, streams and aquifers provides approximately one-third of the water for California’s households, industries and farms.
The news media is invited to accompany DWR snow surveyors near Echo Summit on Jan. 3. The location is Phillips Station at Highway 50 and Sierra at Tahoe Road approximately 90 miles east of Sacramento. Measurements will begin at 11 a.m. Reporters and photographers should bring snowshoes or cross-country skis and park their vehicles along Highway 50. Results should be available by 1 p.m.
Statewide snowpack readings are available on the Internet at:
Electronic reservoir level readings may be found at: