California Water Rights Exceed Supply

Among other serious water challenges, UC Davis researchers have found that in the last century, California has handed out rights to five times more surface water than their rivers produce even in a normal year. On some major river systems (i.e., the San Joaquin Valley), people have rights to nearly nine times more water than flows from the Sierra mountains.

In 2014 UC Davis researchers found that water rights exceed average natural runoff on 16 major rivers and they were only counting junior water rights or those granted after 1914. Pre-1914 or senior water rights and riparian rights weren't included in the study. So that makes the over-promising even more egregious. "The state has over-allocated water in many, if not most, river basins," researchers said. "After 100 years, California's water rights system is struggling to adapt to 21st Century realities of increasing water stress, changing climate, and societal demands for water supply security and a healthy environment."