Droughts in the Western United States and Methods to Improve the Reliability of Urban Water Supply

Much is written nowadays about the scarcity of water in many parts of the United States and the world. Water concerns are well publicized in semi-arid regions of the American southwest, principally California, where there are growing urban areas and large regions that support irrigated agriculture. This paper addresses water supply and water use in regions that exhibit pronounced climatic variability and recurrent drought. The focus of this paper is on the public-supply water sector. This paper argues that the paradigm of building water storage and conveyance facilities in water-endowed regions to export water to regions where freshwater is scarce may be obsolete. Bridging the gap between water supply and water use will require new approaches that better reflect the natural scarcity of water and resources.