Recharging San Joaquin groundwater basin a success

LODI, CA - Groundwater supplies are stressed in many areas of California, where water scarcity alternates with times of deluge. This month, regional partners are taking a step forward on a pilot project that protects groundwater supplies by piping Mokelumne River water to farmers for irrigation. River water is being used instead of pumping groundwater, reducing reliance on strained groundwater supplies.

“This regional partnership has brought additional funding and water to our area that would not otherwise be here. We are really excited about the new pump station and the opportunities for additional groundwater recharge,” said North San Joaquin Water Conservation District Board Member David Simpson.

The partners – North San Joaquin Water Conservation District, San Joaquin County, East Bay Municipal Utility District (EBMUD), and Eastern Water Alliance – are conducting the DREAM project: Demonstration Recharge Extraction and Aquifer Management. As part of the project, North San Joaquin Water Conservation District just finished pumping Mokelumne River water using recently upgraded pumps to irrigate fields of almonds and grapes east of Lodi in San Joaquin County.

The lessons learned from this limited scale pilot may help the partners pursue similar solutions to address the groundwater overdraft in the Eastern San Joaquin basin. To date, nearly 150 acre-feet of Mokelumne River water (about 50 million gallons) has been delivered.

The DREAM project provides North San Joaquin Water Conservation District with up to 1,000 acre-feet of EBMUD surface water from the Mokelumne River that participating landowners use for irrigation instead of pumping local groundwater, thereby storing groundwater in the basin for future use.
During dry years, EBMUD can recover up to half of the delivered water from the groundwater basin when East Bay customers need it most.

“This innovative project allows us to bank water during wet years, making it available during dry years,” said EBMUD Board President Marguerite Young. “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 DREAM partners will take advantage of existing infrastructure to move the Mokelumne River water to farmers and recover groundwater during dry years. Over the next year, EBMUD and North San Joaquin Water Conservation District will construct added infrastructure to deliver groundwater to EBMUD’s Mokelumne Aqueducts, including a three-mile pipeline that will connect to EBMUD’s main aqueducts. Construction is scheduled for the summer and fall of 2020.

“I am pleased to see this innovative concept, in the works for decades, finally come to fruition,” said San Joaquin County Supervisor Chuck Winn. “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. This project serves as a model for other regions to follow.”

San Joaquin County issued the DREAM groundwater export permit in 2017 and has been monitoring groundwater levels since 2018 in advance of groundwater extraction, which could start as early as winter of 2020. All DREAM groundwater extractions are subject to the export permit conditions and will be controlled by North San Joaquin Water Conservation District.

“This project was a dream in the making well before San Joaquin County and EBMUD began discussions to explore the development of a groundwater banking project in 2012,” said San Joaquin County Public Works Director, Kris Balaji. “I credit my predecessor Tom Gau and visionary County staff who had the perseverance to galvanize our partners in finding a way to improve overdrafted groundwater conditions while also enhancing water supplies during dry years.”



DREAM Partners:

The East Bay Municipal Utility District has a proud history of providing high-quality drinking water for 1.4 million customers in Alameda and Contra Costa counties. EBMUD’s wastewater treatment services 685,000 customers and protects San Francisco Bay.

Eastern Water Alliance is an alliance of water districts, Central San Joaquin Water Conservation District, North San Joaquin Water Conservation District, and Stockton East Water District, located over the critically overdrafted Eastern San Joaquin County Groundwater Basin.

North San Joaquin Water Conservation District covers 150,000 acres in the northeast part of San Joaquin County and includes more than 70,000 acres of irrigated farmland.

San Joaquin County Department of Public Works designs, constructs and maintains public roads, bridges, water, wastewater systems, flood control, and solid waste systems to protect the health and welfare of the public and preserve San Joaquin County's infrastructure investments.