The Department of Water Resources (DWR) will conduct its fifth and final manual snow survey of the season, Monday, May 2, at 11 a.m. off Highway 50, near Echo Summit.
Electronic readings currently indicate that snowpack water content has dipped, as anticipated, to 151 percent of the April 1, full season average. May snow survey figures are normally lower than April readings, and used to forecast the spring and summer runoff.
April 1 readings recorded 165 percent of the April 1 full season average, due to heavy storms in late February and March.
"The productive storms at the close of February and March provided us with a good water supply for the year,” said DWR Director Mark Cowin. “In contrast, April experienced below-average precipitation. While April’s below-average precipitation has eased the pressure on the State’s flood control system, this water year is a clear example of how cyclical California’s weather patterns can be. As such, we continue to remind residents to practice efficient water use year round.”
From January to May, manual surveys are conducted up and down the state's mountain ranges around the first of the month. 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 levels for the date.Lake Oroville in Butte County, the State Water Project's principal reservoir, is 113percent of average for the date (93 percent of its 3.5 million acre-foot capacity).Lake Shasta north of Redding, the federal Central Valley Project's largest reservoirwith a capacity of 4.5 million acre-feet, is at 106 percent of average (92 percent ofcapacity). (An acre-foot is 325,851 gallons, enough to cover one acre to a depth of one foot.)
DWR estimates it will be able to deliver 80 percent of requested State Water Project(SWP) water this year. The estimate may change as hydrologic and regulatoryconditions continue to develop.
In 2010, the SWP delivered 50 percent of a requested 4,172,126 acre-feet, up froma record-low initial projection of 5 percent due to lingering effects of the 2007-2009drought. Deliveries were 60 percent of requests in 2007, 35 percent in 2008, and 40 percent in 2009.
The last 100 percent allocation -- difficult to achieve even in wet years due to pumping restrictions to protect threatened and endangered fish -- was in 2006.
The SWP delivers water to more than 25 million Californians and nearly a million acres of irrigated farmland. The mountain snowpack 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 Lake Tahoe on May 2. The location is Phillips Station at Highway 50 and Sierra at Tahoe Road, approximately 90 miles east of Sacramento. 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 http://cdec.water.ca.gov/cgi-progs/snow/DLYSWEQ
Electronic reservoir level readings may be found at http://cdec.water.ca.gov/cdecapp/resapp/getResGraphsMain.action