Jeffrey Mount is a senior fellow at the PPIC Water Policy Center. He is an emeritus professor of earth and planetary sciences and founding director of the Center for Watershed Sciences at the University of California, Davis. Over the past ten years California has experienced wild swings in climate, with two record warm/dry three year periods separated by a year that set the all-time record for statewide precipitation. This increasing climate variability--likely driven by global climate change--is challenging all aspects of water management, including supply, hydropower generation, flood and ecosystem management. Adapting to these changing conditions will require a change in course in water management by all Californians.