In a study published today, Center for Watershed Sciences colleagues Ted Grantham (left) and Joshua Viers report that California has given away five times more surface water than the state actually has, making it hard for regulators to tell whose supplies should be cut during a drought.

The scientists said California’s water-rights regulator, the State Water Resources Control Board, needs a systematic overhaul of policies and procedures to bridge the gaping disparity, but lacks the legislative authority and funding to do so.

Grantham explored the state’s water-rights database as a postdoctoral researcher with the center. Viers directs the Center for Information Technology Research in the Interest of Society at UC Merced. He and Grantham, now with the U.S. Geological Survey, are working to iron out issues with its database and make the information available to policymakers.