SAN JOSE — An emergency $6.7 million plan to make the State Water Project’s California Aqueduct flow backward for roughly 100 miles to bring water from the Bakersfield area to Silicon Valley has been shelved for this year.
The plan, which was developed by the Santa Clara Valley Water District, based in San Jose, would have moved about 35,000 acre-feet of water — enough for 175,000 people a year and about 10 percent of Santa Clara County’s total need this year — from underground aquifers near the town of Wasco in Kern County to San Luis Reservoir, west of Los Banos.
The water was going to be sent north, instead of the usual southward direction, through the aqueduct, a concrete canal that runs along Interstate 5, starting in September. It would have been moved by up to 20 giant diesel pumps installed along the aqueduct.
But because of rains in December and February, the Santa Clara Valley Water District will be able to receive the same amount of water from a more conventional route and has decided to put the highly unusual project on hold for at least a year.
“It’s great news,” said Cindy Kao, imported water manager for the district. “We need that water badly. It would have been extremely difficult if not impossible for us to buy that much water this year on the open market. It would have been extremely expensive and very difficult to find.”
Since 1996, the district, which provides water to 1.8 million people in Santa Clara County, has been in an arrangement with the Semitropic Water Storage District in Kern County. Under the deal, Santa Clara sends excess water it receives in wet years from the Sacramento-San Joaquin Delta south, where it is stored in giant underground aquifers managed by Semitropic, or given to farmers in the area who consume it instead of pumping groundwater.
The idea is that it’s cheaper, and there’s less evaporation, to store water in groundwater banks than to build huge new reservoirs.
In dry years, when it’s time to for the Santa Clara Valley Water District to make a withdrawal, the district takes water from the Delta that would have otherwise gone to Semitropic.
But because of the extreme drought, state and federal officials have dramatically reduced pumping from the Delta in recent years, putting at risk that exchange.
Earlier this year, the state Department of Water Resources told water agencies that they should expect to receive only 10 percent of the amount of water this year that they had contracted from the State Water Project through the Delta.
But after the winter rains, reservoir levels rose, and the state increased that amount to 20 percent.
The Santa Clara Valley Water District had approved the “reverse flow” project in early March and had begun to seek construction bids, with plans to begin work by now.
But the State Department of Water Resources confirmed on March 27 that enough water could be moved through the Delta — due to the rain, reservoir levels and the timing of deliveries to other water agencies — to satisfy the entire 35,000 acre feet that the district was trying to remove from the groundwater bank, using the traditional exchange method.
However, all the engineering studies and environmental studies are done.
“The project could still come back,” said Tim Bramer, engineering unit manager for the Santa Clara Valley Water District. “It would still be something we would consider if the drought continues into 2016.”
Since 1996, the Santa Clara Valley Water District has stored 428,000 acre-feet of water at Semitropic. It has removed a total of 201,000 acre-feet over seven different years.
Other Bay Area agencies with water in the Kern County bank, including the Alameda County Water District and the Zone 7 Water Agency in Livermore, considered partnering with Santa Clara on the reverse flow arrangement. Now, the East Bay agencies will get all the water from the traditional groundwater exchange route through the Delta.
Agencies south of Kern County that receive the water, like Metropolitan Water District of Southern California, aren’t affected because they simply can have Semitropic pump it into the California Aqueduct and flow south.
Paul Rogers covers resources and environmental issues. Contact him at 408-920-5045. Follow him at Twitter.com/paulrogerssjmn.
