Water supply up, but pumps shut down

With the Sierra snowpack’s water content above average, the California Department of Water Resources (DWR) has increased its State Water Project (SWP) allocation to 20 percent for this season.

This follows an announcement two weeks ago that The Bureau of Reclamation was significantly increasing the federal water project supplies for Central Valley Project (CVP) water contractors.

However, as Central California farmers and Southern California urbanites have learned to come to expect, nothing is ever settled in the escalating California water wars. The day before the state announced the increase its allocations, U.S. District Judge Oliver W. Wanger denied a request from state water users to rescind pumping restrictions that were to go into effect April 1 to protect spring-run Chinook salmon and Central Valley steelhead.

Wanger endorsed the National Marine Fisheries Service biological opinion for protecting the salmon and steelhead as acceptable and refused to rescind the scheduled cutback, which means four of the five Delta pumps went down on Thursday as planned. Reduced pumping from the Delta south will likely continue for two months. This is happening with 300,000 acre feet of capacity available in the 2 million acre feet San Luis Reservoir, the major mid-valley storage reservoir for both state and federal water.

A full San Luis is important to valley farmers when the time comes to begin irrigating crops this summer. Cities also count on San Luis water during the heavy-use summer months.

Wanger’s March 31 ruling is the first salvo of what will be a protracted courtroom battle over the management plan for not only the salmon and steelhead, but the Delta smelt minnow as well. The legal battle is now ongoing on Wanger’s Fresno courtroom.

“As the water picture for this year becomes clearer, we can increase our deliveries to farms and communities throughout the state,” said DWR Director Mark Cowin, without addressing the impact of Wanger’s edict. “But the aftermath of three years of drought and regulatory restrictions on Delta pumping to protect fish species will keep this year’s allocation far below normal. This underscores, once again, the need to implement long-term solutions to improve water supply reliability.”

Manual and electronic snow survey readings indicate that statewide, snowpack water content is 106 percent of normal for the date. This time last year, the reading was 81percent of normal for the date.

Snowpack water content normally is at its peak the first of April, although DWR makes a final manual survey the first of May, and electronic readings report conditions daily. DWR may be able to increase the State Water Project allocation to above 20 percent as hydrologists refine runoff projections from today’s snowpack readings and conditions continue to develop.

Lake Oroville, the State Water Project’s principal reservoir, is recovering slowly after three consecutive dry years. Its storage level today is at only 47 percent of capacity, 60 percent of normal for the date. In addition, fishery agency restrictions on Delta pumping continue to reduce the amount of water that can be delivered to contractors and customers in the Bay Area, San Joaquin Valley, Central Coast and Southern California. The final State Water Project allocation, to be set later this spring, will partially depend on how the pumping restrictions to protect fish including Delta smelt, salmon and longfin smelt are applied.

In 2009, the State Water Project delivered 40 percent of customer requests. The average of project deliveries over the past 10 years is 68 percent of the amount requested by the 29 public agencies with long-term contracts to buy SWP water. The 29 contractors deliver water to more than 25 million Californians and 750,000 acres of irrigated farmland.

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