An overview of the key issues of public accountability and water policy innovation that confront urban and agricultural water agencies throughout the country--notably in California where the prospects for future water development have become especially problematic. Focusing on six agencies in the Southern California region, they offer a series of case studies analyzing the issues of water quality, including groundwater contamination and disinfection by-products; reallocation and transfer of existing supplies; and management programs based on pricing changes, the conjunctive use of surface and groundwater supplies, and increased storage capacity aimed at greater efficiencies in stretching those existing supplies.