Chart: Groundwater depletion in California’s Central Valley accelerates during megadrought.

Showing graphs comparing USGS and satellite data, he said, “you can see the huge increase in flooding and increase in drought just over the last six or seven years. We need to see what we can do to stop those depletion trends to keep California from going deeper and deeper into the red.

“The challenge in much of California is the fact that we’ve got this episodic and uncertain delivery of rainfall through the atmospheric rivers,” he continued. “And yet, we need water all the time. The challenge is to actually try to figure out how to increase the storage. We’re probably not going to be building reservoirs, right? So how are we going to be effecting managed aquifer recharge?”

Critical of the state Sustainable Groundwater Management Act’s approach to localizing water decision making by having individual water districts submit required plans, he instead called for statewide, science-based targets. “I think I think that’s the future. We need to give a lot of attention to the storage issue, and how do we balance?” he said.

“I think the state needs to be better prepared to figure out how to do these things,” Famiglietti concluded. “Where are the opportunities? Where are the locations for recharge? How much can we do? Where do we do it? Are the fields in good enough shape? Do they have too many fertilizers that are just gonna end up contaminating the groundwater? These are all things that need our attention, actively.”