The Los Angeles river, with the downtown LA skyline in the distanceEkaterina Chizhevskaya/Getty ImagesIn 2023, a parade of atmospheric rivers brought months of heavy precipitation to much of California, filling reservoirs and raising snowpack far above average levels. This flood of water was a major relief after nearly two decades of drought. But a seismic study has now revealed that water on the surface did little to restore the states depleted reserves underground.There was very limited recovery, compared to the groundwater lost over the recent droughts, says Shujuan Mao at the University of Texas at Austin.