The Department of Water Resources (DWR) today increased the 2011 State Water Project (SWP) allocation to 70 percent of contractors' requests, up 10 percent from the January figure.
"As a result of recent precipitation and good water supply conditions, we have increased the allocation,” said DWR Director Mark Cowin. "However, we will continue to conservatively plan for future water needs as we progress through the remainder of the rainy season."
The State Water Project water allocation will increase from 2,503,276 acre-feet to 2,920,488 acre-feet attributable to recent precipitation, runoff and the above-average snowpack.
In 2010, the State Water Project 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.
Precipitation so far this winter is approaching average for the entire water year (Oct. 1 - Sept. 30). With recent snowfall in the Sierra and other mountain ranges, statewide runoff is about average for the date and expected to go above average.
Statewide, snowpack water content is 129 percent of average for the date and 125 percent of the average, April 1 seasonal total. Additionally, a majority of California’s reservoirs are above normal storage levels.
Lake Oroville in Butte County, the State Water Project's principal reservoir, is at 113 percent of normal storage for the date. It currently is holding 2,973,694 acre-feet, which is 84 percent of its 3,537,600 acre-foot capacity. Spills were made from the reservoir this week to maintain flood control space. Lake Shasta north of Redding, the federal Central Valley Project's largest reservoir with a capacity of 4.5 million acre feet, is at 117 percent of normal storage for the date, which is 91 percent of its capacity.
Current storage and snowpack levels are good news for California’s agricultural communities and municipal water users.
The State Water Project delivers water to more than 25 million Californians and nearly a million acres of farmland.
Projections of SWP deliveries are adjusted through the winter and early spring as hydrologic conditions develop. DWR is conservative in its projections since farmers and others can suffer if expected amounts cannot be delivered. In November, DWR's first estimate for 2011 was that it would be able to deliver 25 percent of requests. The initial estimate – always low because it is made before the months of heaviest precipitation – was raised to 50 percent in December, and more recently rose to 60 percent in January.
SWP 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 because of pumping restrictions to protect threatened and endangered fish – was in 2006.
Snowpack water content readings from electronic sensors are available on the Internet at http://cdec.water.ca.gov/cgi-progs/snow/DLYSWEQ
Historic readings from snowpack sensors are posted at http://cdec.water.ca.gov/cgi-progs/rpts1/DLYSWEQ
Electronic reservoir level readings may be found at http://cdec.water.ca.gov/cdecapp/resapp/getResGraphsMain.action