The latest round of spring storms have increased the water content in California’s statewide mountain snowpack to 143 percent of normal, according to the California Department of Water Resources (DWR). “This is good news after three years of drought, but we still face water shortages in many parts of the state,” said DWR Director Mark Cowin. “State Water Project storage is well below average and Delta pumping restrictions to protect native fish species will continue to hamper our ability to deliver water to millions of California homes, businesses and farms. If we are to ensure an adequate water supply for the future, it is critical that we conserve water and develop smarter, more sustainable ways to manage our water resources.”
Lake Oroville in Butte County, the State Water Project’s principal storage reservoir, is still only 59 percent full or 71 percent of normal for the date. And fishery agency mandates to protect Delta smelt, longfin smelt, salmon and other species affect the amount of water that can be pumped from the Sacramento-San Joaquin Delta. DWR currently estimates it will be able to deliver only 30 percent of requested State Water Project water to cities and farms in the San Francisco Bay Area, San Joaquin Valley, Central Coast and Southern California.
“Initial results of our final snow survey indicate we may be able to increase the allocation above 30 percent, but nowhere close to the requested amounts,” Cowin said. The 29 public agencies that purchase State Water Project water this year collectively requested 4,171,996 acre-feet of water. At 30 percent, the current allocation would deliver 1,251,601 acre-feet for approximately 25 million Californians and 750,000 acres of irrigated farmland. Last year, the State Water Project delivered 40 percent of requests.
The average allocation over the past 10 years is 68 percent of the requested amount. After three consecutive drought years, DWR late last year set the initial 2010 State Water Project allocation at only 5 percent of requested deliveries. The allocation rose incrementally to 15 percent, 20 percent, and 30 percent as the snowpack accumulated during winter and early spring.
Snow surveyors from DWR and cooperating agencies manually measure snowpack water content around the first of the month from January through May. In addition, remote sensors electronically report their readings. Manual surveys will continue up and down the state for several more days. Electronic sensor readings show northern Sierra snow water equivalents at 188 percent of normal for the date, central Sierra at 121 percent, and southern Sierra at 139 percent.
Electronic sensor Web sites