This paper documents the methodology and results of a comprehensive water demand and conservation study conducted in 2003 and 2004 under the direction of the San Francisco Public Utilities Commission (SFPUC) in conjunction with its 28 wholesale customers. These customers are represented by the Bay Area Water Supply and Conservation Agency (BAWSCA). The SFPUC supplies water to about 1.6 million people within the San Francisco Bay Area plus about 700,000 within the City of San Francisco itself.
A detailed benefit-cost analysis was conducted using the Demand Side Management Least-Cost Planning Decision Support System (DSS) model for 32 conservation measures using the individual customers' DSS model. Thirty-year water savings, benefit–cost ratios, and the cost of water saved were computed for each measure.
Based on compiling the results from the individual customer demand models, it was found that the current plumbing and appliance codes would reduce overall 2030 water demand by 7.8% and that packages of additional water conservation measures could reduce demands by an additional 2–6%, depending upon the level of conservation implemented. Overall, the study represents one of the largest water demand and conservation evaluation projects undertaken in the United States.