ABSTRACT
Historically, advances in water system management have been motivated largely by socioeconomic and environmental considerations. In recent decades, the increasing expense and concern over the environmental impact of developing traditional water supplies (e.g., reservoirs) have encouraged innovative uses of existing facilities (e.g., conjunctive use and pumped storage schemes) and have led to expanded demand management efforts; there has been a shift from water resources development to water resources management. In more recent years, continued growth in water demands, increasing threat of water scarcity, and heightened environmental concerns have caused even these innovations to yield "diminishing marginal returns" at times. These economic and environmental conditions, combined with periodic and sometimes catastrophic droughts and floods, have spurred further efforts to improve traditional supply augmentation and demand management measures and have motivated the consideration and use of water transfers.
