Deputy Secretary of the Interior David J. Hayes and Bureau of Reclamation Commissioner Michael L. Connor forecasted likely increases in water supplies in 2011 for the Bureau of Reclamation’s Central Valley Project (CVP) based on measurements of the early snowpack, runoff, reservoir storage information and actions by CVP partners.
“The new year starts with an encouraging water supply forecast, thanks to the precipitation delivered by Mother Nature and the ongoing efforts of the Bureau of Reclamation and its partners in the Central Valley Project,” said Hayes. “If present conditions continue, agricultural, municipal and industrial water contractors as well as wildlife refuges are likely to receive increased water allocations in 2011.”
The combination of three factors—above-average early precipitation and snowpack in the Sierra Nevada Mountains, improved carryover reservoir storage and a series of specific water augmentation activities developed in 2010—makes it likely that CVP water allocations for Water Year 2011 will exceed those of 2010.
The California Department of Water Resources’ first snow survey of the water year, held on December 28, 2010, reported snow water content to be 198 percent of normal statewide—as compared to 85 percent of normal on the first survey of last year. Precipitation in Northern California is currently approximately 68 percent of the seasonal average compared to 33 percent last year at this time. In addition, the snow water content in the Northern Sierras is approximately 174 percent of average for this date. Precipitation in the Upper San Joaquin River Basin is 38.03 inches as measured at Huntington Lake, compared to a 30-year average of 16.55 inches or 230 percent of average.
“Although these numbers are encouraging, it is still early in the water year, and winter precipitation will affect the final allocation,” Connor noted. “In the meantime, we will continue to work with our partners to improve the factors we can control, such as improved water storage and water augmentation activities.”
The CVP’s carryover storage from Water Year 2010 to 2011 was 7.4 million acre-feet on October 1, 2010, compared to a 4.4 million acre-feet carryover from WY 2009 to 2010. As of January 3, 2011, total CVP reservoir storage (including Millerton Reservoir) has improved to 8.3 million acre-feet of water. This compares to 4.9 million acre-feet on the same day in 2010.
Water supply outlook
Based upon this information, the following represents the initial CVP water supply outlook based on an average or better water year. For this initial outlook:
* Agricultural water service contractors North-of-Delta are being forecasted 100 percent of their contract supply of 443,000 acre-feet, while agricultural water service contractors South-of-Delta are being forecasted 45 percent of their contract supply of 1.965 million acre-feet.
* Municipal and Industrial water service contractors North-of-Delta are being forecasted 100 percent of their contract supply and contractors South-of-Delta are forecasted to receive 75 percent of historic use.
* Sacramento River Settlement Contractors and Exchange Contractors, who receive their CVP water supply based upon a claimed pre-CVP water right, are being forecasted 100 percent of their contract supply of 2.2 million acre-feet and 800,000 acre-feet respectively.
* Wildlife refuges (Level 2) North- and South-of-Delta, whose allocations are based upon a pre-established inflow trigger to Shasta Reservoir, are being forecasted 100 percent of their contract supply of 422,000 acre-feet.
* Friant Division contractors, whose water supply is delivered from Millerton Reservoir on the San Joaquin River, are being forecasted 100 percent of Class 1water and 15 percent of Class 2 out of a total contract quantity of 800,000 acre-feet and 1,400,000 acre-feet respectively.
* Eastside water service contractors and pre-CVP water rights contractors, whose water supply is delivered from New Melones Reservoir on the Stanislaus River, will be allocated their full contract supply of 155,000 acre-feet and 600,000 acre-feet respectively.
The first forecast provided by this outlook will be followed by an official water allocation announcement of Water Year 2011 for the CVP which is planned for mid-February, as required by contract terms. Water supply updates will then be made monthly or more often as appropriate and will be posted on Reclamation’s website at http://www.usbr.gov/mp/pa/water.
For additional information on this Water Supply Outlook, please visit http://www.usbr.gov/mp/pa/water or contact the Mid-Pacific Region’s Office of Public Affairs at 916-978-5100 (TTY 916-978-5608) or e-mail [email protected].