A Water RECHARGE
Engineer develops system to replenish depleted groundwater aquifer
By Rebecca Wass
On a one-acre parcel of land where rows of 20-year-old almond trees once stood on Fresno State’s farm, a transformation is underway. And, while it may not look like much from the surface, those involved hope it will address a water shortage that plagues much of the state and its fertile farmland.
In October, an underground pipe system was laid for what is the beginning of the University’s only subsurface artificial groundwater recharge system.
“This pipe system will transport any runoff water or excess surface water and facilitate the percolation of water right into the groundwater aquifer,” says Cordie Qualle (pictured), Fresno State civil engineering faculty fellow and interim director of the California Water Institute.
It is estimated that around 125 million acre-feet of water has been taken out of Central Valley groundwater aquifers in the past century, Qualle says. Within the past decade, an estimated 20 million acre-feet has been withdrawn.
Groundwater recharge means using rain or sources of surface water to gradually filter deep into the ground where it is stored in the aquifer below the water table. Groundwater recharge sources can be found in various forms throughout the Valley such as rivers, lakes and manmade ponds that are persistent sources of water.
“Recharge is a common practice, however, using agricultural land for recharging groundwater aquifers is something new,” Qualle says. “This project will allow us to research how feasible it is for farmers to implement recharge systems within their fields that do not impact their farming operations.”
Qualle says the depletion of groundwater aquifers, affecting water quality, was one of the many effects of the 2012-16 California drought. “In the context of agriculture, many farmers had no other choice than to use groundwater to compensate for the loss of surface water that they would normally use for irrigation uses.”
His proposed solution is to recharge groundwater aquifers that have been critically overdrafted and develop management plans to prevent similar issues.
He enlisted the help of civil engineering graduate student Gabriela Bonilla, who was working in the water sector and heard about Qualle’s vision. Bonilla then introduced Qualle to Greg Wegis, of Wegis and Young Property Management, who had developed a similar groundwater recharge system for his farm.
The research team also partnered with LIDCO, INC, CalWest Rain, Grundfos Pumps Corporation, Red-Trac, City of Clovis, Moore-Twining Associates Inc., Davis Instruments, Fresno State Farm, the Agriculture Research Institute and other donors on various aspects of the project.
Qualle joined the Lyles College of Engineering at Fresno State as a full-time faculty member in 2017 after nearly 40 years in the private civil engineering sector.
“That same year we had a huge rainfall and the Valley’s water infrastructure could not keep up,” he says. “We had a lot of excess water and a lot of it was lost. If the water is not captured, it leaves the Valley in several ways, primarily through the San Joaquin River or the Kings River to the Delta and San Francisco Bay. It occurred to me as I watched all that water go down the river there ought to be some way we can capture that water.”
Starting this summer, students from the Lyles College, like Bonilla, will work to analyze the impact on groundwater aquifers and determine the economic effects of the recharge system. Students will collect data to determine soil properties, analyze energy consumption and conduct water quality analysis.
“Water is vital, and we must find a way to take care of it,” says Bonilla, who graduated in May. “Since starting this program, water has become a passion of mine. We truly hope that this research contributes toward mitigation efforts to sustainably manage our groundwater aquifers while continuing to support our agricultural community.”
— Rebecca Wass is a communications specialist for the Lyles College of Engineering at Fresno State.
