California Water Conservation Case Studies: Paving the Way for a Water Efficient State Marsha Prillwitz, Chief Office of Water Use Efficiency California Department of Water Resources Abstract Between 2000 and 2030, California’s population is expected to grow by 17 million people, a 50 percent increase in population. Combined with reduced surface water supplies, an unsustainable overdraft of the State’s groundwater, and unmet environmental water requirements, the challenges to meet California’s water needs are greater than ever. Water conservation, water recycling and desalination have been identified as primary strategies to meet the demand. Significant investments are necessary to support these actions. In 2001, the State invested $12 million to co-fund 46 agricultural and urban water conservation projects. Following is an overview of the process and the selected projects as well as a more detailed discussion of four agricultural and five urban projects with noteworthy results. The four agricultural projects are: a technical assistance program for irrigation districts; measurement of non-point source reduction in vineyards with improved irrigation efficiency; research on the variability of soil salinity on farms; and an evaluation of salt-tolerant crops. The five urban projects are: a demonstration of water conservation in urban supermarkets; an x-ray processor retrofit program for hospitals; a high efficiency washing machine rebate program; a weather-based controller retrofit program for urban landscapes; and an investigation of potential urban water conservation.