The California Department of Water Resources on Wednesday announced an initial allocation of five percent of requested deliveries to State Water Project (SWP) contractors in calendar year 2014.
The initial allocation is a conservative estimate of what DWR expects it can deliver as a percentage of the total amount requested by the public water agencies that contract for SWP deliveries.
“We hope things improve with this winter's storms,” said DWR Director Mark Cowin, “but there is no guarantee that 2014 won't be our third consecutive dry year. Today's allocation is a stark reminder that California's fickle weather demands that we make year-round conservation a way of life.”
It is still early in the water year; DWR will update the allocation as the winter progresses based on mountain snowpack accumulation. On average, half of California's annual precipitation occurs in December through February, and three-quarters occurs from November through March.
Initial water delivery estimates are conservative because they are made before the wettest period of the year. The lowest previous initial SWP allocation, also five percent, was for calendar year 2010.
Made on the heels of the 2007-09 drought, the 2010 allocation was eventually increased to 50 percent of the slightly more than four million acre-feet of water requested by the 29 public agencies that receive SWP water. Winter storms increased the second-lowest initial allocation of 10 percent for calendar year 1993 to 100 percent of requested deliveries.
Storage levels in the state's major reservoirs largely dictate the initial SWP allocation.
Lake Oroville in Butte County, the State Water Project's principal reservoir, is at 41 percent of capacity (66 percent of its historical average for the date). Lake Shasta north of Redding, the federal Central Valley Project's largest reservoir, is at 37 percent of capacity (61 percent of average).
San Luis Reservoir in Merced County – a vital south-of-Delta supply pool for both the State Water Project and Central Valley Project – holds only 25 percent of capacity (42 percent of average for the date) due both to dry weather and Sacramento-San Joaquin Delta pumping restrictions to protect Delta smelt and salmon.
The final State Water Project allocation this year was 35 percent of the 4.17 million acre-feet requested by agencies that collectively deliver water to more than 25 million Californians and 700,000 acres of farmland in the Santa Clara Valley, San Joaquin Valley, and Southern California.
In 2012, the final allocation was 65 percent. It was 80 percent in 2011, up dramatically from an initial allocation of 25 percent. The final allocation was 50 percent in 2010, 40 percent in 2009, 35 percent in 2008, and 60 percent in 2007.
The last 100 percent allocation – difficult to achieve even in wet years because of Delta pumping restrictions to protect threatened and endangered fish – was in 2006.
DWR is convening its annual winter outlook science workshop this week to develop an experimental seasonal forecast which will be posted on DWR’s website later in the month. Regardless of whether the experimental forecast suggests wet or dry conditions, DWR will continue to prepare for the possibility that water year 2014 may become a third dry year.
If 2014 is dry, the greatest risks for public health and safety impacts stem from the increased chances for major wildfires and from drinking water shortages in some rural small water systems relying on fractured rock groundwater.
Minimal surface water allocations to some agricultural areas, especially in the San Joaquin Valley, can result in economic impacts to growers and increased land subsidence where groundwater overdraft occurs.
As provided for in Gov. Brown’s May 2013 Executive Order to expedite review and processing of voluntary water transfers, DWR has been working to streamline the process by improving contracting procedures for transfers dependent on SWP facilities, facilitating fast-tracking of transfers with appropriate supporting documentation, and improving coordination with other agencies involved in approving transfers, including the U.S. Bureau of Reclamation and State Water Resources Control Board.
In partnership with the National Integrated Drought Information System program, DWR organized four classes this fall on drought preparedness and water conservation for small water systems. DWR co-sponsored a drought preparedness workshop for urban water agencies with the National Water Resources Institute. Presentations from the workshop are available at http://www.nwri-usa.org/drought.htm .
DWR and California State University Fresno will hold an agricultural drought preparedness workshop in December.