Water pump test deemed a success
LODI — Four agencies involved in an effort to recharge groundwater in northern San Joaquin County said an experimental project to supply farmers with river water has been a success.
A test run of a new pump station as part of the Demonstration Recharge Extraction and Aquifer Management project — or DREAM — was concluded last month.
The goal is to pump as much as 1,000 acre-feet of East Bay Municipal Utilities District water from the Mokelumne River that farmers can use for irrigation, rather than pumping groundwater from wells.
Using river water will help store existing groundwater in the basin, and help it recharge during rain seasons. The project is a collaboration between the North San Joaquin Water Conservation District, San Joaquin County, East Bay Municipal Utility District and Eastern Water Alliance.
For one month, the four agencies tested a new pump station between the Mokelumne River and Tretheway Road, extracting 150 acre-feet of water — 50 million gallons — and delivering it to local grape growers.
Testing ended last weekend, NSJWCD board member David Simpson said.
“We took out the old pump from the 1960s, which was inefficient and had problems,” Simpson said. “And we rebuilt it with a modern, variable frequency drive pump where we were able to set the horsepower used for pumping water, rather than just pushing a button and letting it do what it does. We’re happy with the way it worked out.”
The water extracted from the river was able to benefit about half a dozen farmers and growers east of Lodi, Simpson said.
The next phase of the DREAM project is to construct a pipeline south from Pixley Slough to a Mokelumne River aqueduct, where EBMUD will reclaim as much as 500 acre-feet of water to which it has rights.
Ultimately, water pumped from the Mokelumne will travel to Pixley Slough, where NSJWCD water will be released in flows to farmers, and EBMUD water will be transferred to the aqueduct for that agency’s customers.
In addition, Simpson said water will not be extracted from the river on a year-round basis, either. What will happen, he said, is that NSJWCD will only use its share of water in the summer months, and EBMUD will then reclaim its 500 acre-feet during the winter months, when farmers won’t need to irrigate.
“This innovative project allows us to bank water during wet years, making it available during dry years,” EBMUD Board President Marguerite Young said in a media statement. “Not only does this support water supply reliability in the East Bay, it also benefits San
Joaquin County farmers and replenishes natural groundwater reserves, which protects the environment.”
The project is only temporary, Simpson said, adding it may take a few years to actually pump the entire 1,000 acre-feet of water allocation into the slough.
“There is a lot of misconception about the project out there,” he said. “None of the water district directors want to just launch into a program that dries up all the river water or groundwater. We’re trying to do exactly the opposite and hopefully bring more groundwater into the basin.”
The DREAM project had been in the planning stages for years, but it was the state’s Sustainable Groundwater Management Act that motivated the four agencies to come together and make it a reality.
Signed into law by Gov. Jerry Brown in 2014, the SGMA requires governments and water agencies of high and medium priority basins to halt overdraft and bring groundwater basins into balanced levels of pumping and recharge. Basins should reach sustainability within 20 years of incorporating plans, or by 2040.
According to a project overview on the NSJWCD website, the district’s annual overdraft has about 70,000 acre feet.
The project should save about 1 acre-foot of groundwater a year, or 325,851 gallons, Simpson said.
“We want to be as transparent as we can be,” Simpson said. “This isn’t something we’re trying to hide in the middle of the night. If the project does work, it could lead to quite a bit of water from EBMUD.”
In a media statement issued this week, San Joaquin County Supervisor Chuck Winn, who represents Lodi as part of District 4, said he was pleased to see the project come to fruition.
“The resulting DREAM project will not only help agriculture, fish, recreation and the environment, but it will also provide a drought buffer for local communities in Eastern San Joaquin County by providing an alternative water source when surface water is unavailable,” he said. “This project serves as a model for other regions to follow.”