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Few storms have graced California so far this winter, but those that did — in mid — December and early February – will allow the California Department of Water Resources (DWR) to increase water deliveries to most customers of the State Water Project (SWP) by an additional 204,000 acre-feet (AF).
The modest increase in SWP allocation amounts to enough water to meet the needs of approximately 408,000 households for a year. DWR officials are confident they can supply the additional water thanks to runoff of December and February storms that was pumped from the Sacramento-San Joaquin Delta to San Luis Reservoir near Los Banos. The reservoir holds 627,000 acre-feet more water now than it did at this time a year ago. Water to meet the slight increase in allocation will not come from Lake Oroville in Northern California; DWR seeks to preserve storage in that keystone SWP reservoir to meet demands in late 2015 and next year, should it prove dry as well.
The additional deliveries will increase this year’s SWP allocation from 15 percent to 20 percent, for total deliveries of 840,000 acre-feet of water. The 29 public water agencies that take delivery of SWP supplies have requested 4,172,686 AF. A 20 percent allocation would be the second-lowest since 1991, when agricultural customers of the project got a zero allocation and municipal customers received 30 percent. Last year, SWP deliveries were 5 percent of requested amounts for all customers.
The slight increase in SWP deliveries will help to meet the needs of water districts in the San Francisco Bay Area, Santa Clara Valley, San Joaquin Valley, and Southern California. The past three years of drought have seriously diminished local reservoirs and aquifers relied on by these agencies. They also have used most of the water carried over in SWP reservoirs from 2013 and earlier years. Roughly 25 million Californians and nearly one million acres of irrigated farmland, mostly in Kern and Kings counties, depend upon the SWP for at least some of their supplies.
“We’re grateful that close coordination among water and wildlife agencies in managing limited runoff this winter will afford State Water Project contractors a slight increase in their supplies,” said DWR Director Mark Cowin. “We’re confident that this water, delivered to local districts around the state, will help offset some economic harm of this extended drought.”
The new SWP allocation of 20 percent replaces the allocation of 15 percent announced on January 15. The initial allocation of 10 percent, made on December 1, was increased after mid-December storms boosted river flows and tight coordination among federal and state water and wildlife-protection agencies allowed the SWP to store runoff south of the Sacramento-San Joaquin Delta without violating statutory and regulatory obligations to protect wildlife and water quality.
The last 100 percent SWP allocation — difficult to achieve even in wet years because of Delta pumping restrictions to protect threatened and endangered fish species — was in 2006. SWP allocations for recent years:
2014 – 5 percent
2013 – 35 percent
2012 – 65 percent
2011 – 80 percent
2010 – 50 percent
2009 – 40 percent
2008 – 35 percent
2007 – 60 percent
The October-through-April season when California on average gets 90 percent of its precipitation is winding down. This year is shaping up as a critically dry fourth consecutive year of drought. Thanks to a couple of large storms, one in December and another in February, major reservoirs in Northern California hold more water now than at this time last year, but most remain below historical average storage for this time of year. Major reservoirs are generally even more depleted in Southern California, where water districts depended heavily on local supplies last year.
DWR snow surveyors will make manual measurements of the Sierra Nevada snowpack. Electronic readings show the mountain snowpack statewide stands at just 19 percent of typical water content for this time of year. That snowpack typically provides about a third of the water people use in California each year. Without a series of major storms in the remaining weeks of winter, Californians cannot expect the Sierra snowpack to replenish reservoirs and groundwater basins.
In January 2014, Gov. Edmund G. Brown Jr. declared a drought state of emergency and asked Californians to voluntarily curb their water use by 20 percent. The state recorded 5,620 fires during calendar year 2014 resulting in 90,606 acres burned, and about 1,000 fires more than the annual average of the preceding five years. Vast tracts of farmland have been fallowed and some communities have been short on drinking water. Every Californian can help stretch the state’s limited supplies by using water carefully. Outdoor landscaping needs little water in the winter, so shut off sprinklers, especially for the first couple of weeks after a rain. Replace washers in leaking faucets or make other repairs to stop leaks. Run dishwashers and clothes washers only with full loads. For more water-saving tips, visit saveourwater.com.