Sacramento Bee (Feb. 22, 2014) — Jay Lund, director of the Center for Watershed Sciences at UC Davis, says the downside of drip op irrigation is that it can deplete groundwater. “When you tighten the irrigation efficiency in the Central Valley, most of what you’re doing is reducing recharge to groundwater,” Lund said. “So you have a high technical efficiency on your farm and have not improved the efficiency of the Valley.”