This April 16, 2014, conference at the University of California, Davis, brings together scientists, water managers, policy-makers, engineers, and other stakeholders to identify key challenges and solutions for a sustainable future. As climate changes, California will face decreased snowpack, earlier peaks in runoff, unknown changes in groundwater recharge, and more extreme events, such as drought. Many uncertainties exist, however, about how these changes will influence groundwater resources and management.