Sacramento, Calif. (PRWEB) February 25, 2013
The Bureau of Reclamation today announced the initial Water Year 2013 water supply allocation for Central Valley Project agricultural contractors, municipal and industrial contractors and federal refuges.
The California Department of Water Resources reports that snowpack and precipitation in the Sierra Nevada are below normal with the snow water content statewide at 70 percent of average for this time of year. Additionally, DWR’s February WY 2013 Runoff Forecast indicates a dry water year type for the Sacramento Valley and a critical water year type for the San Joaquin Valley.
The 2013 water year is unfolding in a unique way. Reclamation began WY 2013 (October 1, 2012, to September 30, 2013) with 6.9 million acre-feet of carryover storage in six key CVP reservoirs, which is 98 percent of the 15-year average for October 1. Storms in late November and December resulted in above-average snowpack conditions in Northern California and contributed to above-average storage in Shasta and Folsom Reservoirs; however, the San Joaquin River watershed did not fare as well. This mixed start to the water year was then followed by one of the driest combined Januarys and Februarys on record, leading to what has become a challenging water year.
In addition, water supplies from the state and federal pumps in the south Delta have been reduced significantly this year to protect delta smelt, a threatened species under the Endangered Species Act. Although Reclamation has operated the CVP in a manner consistent with the biological opinion designed to protect the smelt, unanticipated numbers of smelt have been observed at the pumps. Storms in December 2012 flushed large amounts of sediment into the Delta, which may have set up a situation for elevated delta smelt migration into the central and south Delta well into February. Reclamation began to cut back on pumping operations in late December to protect the smelt, and pumping reductions have been required throughout January and February.
“While we continue to hope for additional precipitation during the remainder of the rainy season, we are also continuing to work with our federal, state and local partners to improve this year’s supply and to find a comprehensive, long-term solution that will achieve the dual goals of a reliable water supply for California and a healthy Bay Delta ecosystem that supports the state’s economy,” stated Mid-Pacific Regional Director David Murillo.
Reclamation determines the allocation of CVP water for agricultural, environmental, and municipal and industrial purposes based upon many factors. This initial allocation, based on a conservative runoff forecast, is driven by very dry hydrologic conditions in January and February, water quality requirements, flow objectives, relative priority of water rights, and endangered species protection measures, including operational adjustments in accordance with biological opinions to protect threatened and endangered fish species.
North of the Delta Contractors
Agricultural water service contractors North-of-Delta are allocated 75 percent of their contract supply of 443,000 acre-feet.
M&I water service contractors North-of-Delta who are serviced by Shasta Reservoir on the Sacramento River are allocated 100 percent of their contract supply.
Sacramento River Settlement Contractors, whose water supply is based upon senior water rights and is subject to pre-established Shasta Reservoir inflow criteria, are allocated 100 percent of their contract supply of 2.2 million acre-feet.
M&I water service contractors North-of-Delta who are serviced by Folsom Reservoir on the American River are allocated 75 percent of their historic use.
The Contra Costa Water District, which receives water directly from the Delta, is allocated 75 percent of its historic use amount of 170,000 acre-feet.
South of the Delta Contractors
Agricultural water service contractors South-of-Delta are allocated 25 percent of their contract supply of 1.965 million acre-feet.
M&I water service contractors South-of-Delta are allocated 75 percent of their historic use.
San Joaquin River Exchange and Settlement Contractors, whose CVP water supply allocation is subject to pre-established Shasta Reservoir inflow criteria, are allocated 100 percent of their contract supply of 875,000 acre-feet.
Wildlife refuges (Level 2) North- and South-of-Delta, which also have allocations subject to pre-established Shasta inflow criteria, are allocated 100 percent of their contract supply of 422,000 acre-feet.
Friant Division Contractors
Friant Division contractors’ water supply is delivered from Millerton Reservoir on the upper San Joaquin River. The first 800,000 acre-feet of water supply is considered Class 1, and the next 1.4 million acre-feet is considered Class 2. Based upon DWR’s February WY 2013 Runoff Forecast, the Friant Division water supply allocation is 65 percent of Class 1 and 0 percent of Class 2.
Eastside Water Service Contractors
Eastside water service contractors (Central San Joaquin Water Conservancy District and Stockton East Water District), whose water supplies are delivered from New Melones Reservoir on the Stanislaus River, are allocated their full contract supply of 155,000 acre-feet.
Changes to hydrology and opportunities to exercise operational flexibility of the CVP are factors and conditions that will influence allocations as the water year progresses. Water supply updates will be made as appropriate and will be posted on Reclamation’s website at http://www.usbr.gov/mp/pa/water.
Reclamation has also developed the CVP Water Plan 2013 that identifies actions for WY 2013 to help support water management efforts as hydrologic conditions develop. The plan is also available on the above website.