- The Department of Water Resources (DWR) will conduct its second manual snow survey of the winter at 11 a.m., Friday, Jan. 28, near Lake Tahoe.
The Department of Water Resources (DWR) will conduct its second manual snow survey of the winter at 11 a.m., Friday, Jan. 28, near Lake Tahoe.
Electronic readings indicate that snowpack water content has changed little this month, so far gaining only about an inch since Jan. 1. The water content is 79 percent of the April 1 seasonal average. This compares to an average reading of 55 percent for today’s date.
January has been unusually dry after the heavy storms of October, November and December, recording only about 13 percent of average precipitation for the month.
“Our always-changing weather reminds us that we must always practice conservation,” said DWR Director Mark Cowin. “We’re still optimistic we will have a good water supply year, but we’re only halfway through the winter and still face uncertainty about delivery restrictions as well as the weather.”
DWR estimates it will be able to deliver 60 percent of requested State Water Project (SWP) water this year. The estimate will be adjusted as hydrologic and regulatory conditions continue to develop.
In 2010, the SWP delivered 50 percent of a requested 4,172,126 acre-feet, up from a record-low initial projection of 5 percent due to lingering effects of the 2007-2009 drought. 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, industry and farms as it slowly melts into streams and reservoirs.
Manual surveys are conducted up and down the state’s mountain ranges on or about the first of January, February, March, April and May. The manual surveys supplement and provide accuracy checks to real-time electronic readings as the snowpack builds, then melts in early spring and summer. April 1 is when snowpack water content normally is at its peak before the spring runoff.
California’s reservoirs are fed both by rain and snowpack runoff.
Most of the state’s major reservoirs are above normal storage levels for the date. Lake Oroville in Butte County, the SWP’s principal reservoir, is 102 percent of average for the date (67 percent of capacity). Remaining winter weather will determine whether it fills to its 3.5 million acre-foot capacity. Lake Shasta north of Redding, the federal Central Valley Project’s largest reservoir with a capacity of 4.5 million acre-feet, is at 112 percent of average (76 percent of capacity).
The news media is welcome to accompany DWR snow surveyors near Lake Tahoe this Friday. The location is Phillips Station at Highway 50 and Sierra at Tahoe Road, about 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