The purpose of the study was to determine the social, economic, and health and safety impact of selected recreational activities on, in, or near the terminal reservoir. A preliminary, or basic, cost-benefit mathematical model was designed to include consideration of these factors, and a recommended program for its extension and refinement was developed. Analysis was made of the economic influence on surrounding land values of four prototype reservoirs: closed, domestic supply only; recreational use only; multipurpose, no body-contact sports; multipurpose, including body-contact sports. For the three reservoirs permitting recreational use, the overall economic influence of recreational usage was estimated, and the available data on reservoir water quality were analyzed. A nationwide survey (48 States responding) was performed to determine policies and experience relating to recreational use of the domestic water supply reservoir. Recommendations were developed for coordinated, single-agency, river basin-oriented water resource management suitable for nationwide application based on the England/Wales system. (WRSIC abstract)