The amount of water pumped out of the Sacramento-San Joaquin River Delta would have to be cut in half if vulnerable fish populations are going to be preserved for future generations, a state report declared Tuesday.
The 190-page study by the State Water Resources Control Board is nonbinding, but it could shape how communities from the Bay Area to San Diego divvy up California's most precious resource.
The document, issued by the five-member board after nine months of scientific study, determined that 75 percent of runoff from snowpack and rainfall would need to funnel through the delta to San Francisco Bay and the ocean in order to sustain the estuary's most important wildlife and habitats, known in legal parlance as "public trust" resources.
Right now, about 50 percent of the state's runoff flows through the delta all the way to the ocean. The other 50 percent goes to cities and farms. Raising the flow into the ocean from 50 percent to 75 percent would require taking away roughly half of what cities and farms now get, according to the report.
"The board has finally put to rest the argument about whether the delta needs more water," said Cynthia Koehler, water legislative director with the Environmental Defense Fund. "You can't divert 50 percent of the flows and think the fish and ecosystem are going to be just fine."