One thing that’s become clear amid the fallowed cropland and rationing is that there is not enough water storage in California to sustain all the competing interests. The dilemma has again put a spotlight on the precious water that gets away.
In an average year, rain and snowmelt in California generate about 71 million acre-feet of water, some of which is captured in reservoirs or groundwater basins. An acre-foot is the amount needed to cover an acre with a foot of water, enough to supply an average household for a year.
About 32 percent of the 71 million acre-feet is used for agriculture and 10 percent for urban areas, according to the state Department of Water Resources’ chief hydrologist, Maury Roos. About 35 percent of the total is reserved by law to help river ecosystems, wetlands and fisheries, and to maintain a healthy flow of water in the Sacramento-San Joaquin River Delta. That leaves about 21 percent of the total to flow out into the ocean without being used for anything, according to Roos’ calculations. “That is the segment we can capture more of,” Roos said. “If we could store more of that, we would have a larger water supply.”