ABSTRACT
There are three major groups of problems of matching water demand and supply in the United States: (1) those of timing discontinuities when fluctuations in the availability of water supply do not correspond to those in demand for water and water-derived services; (2) those of quality, where the natural supply does not meet quality requirements of one or more important uses; and (3) those of quantity, where there is a consistent inequality between demand and available supply in a region or locality. Technology has made contributions toward partial solutions within each of these major problem areas in the past, and promises further achievement in the future. An understanding of the opportunities and challenges facing the application of technology to water development may well begin with a description of each of these problems and the approaches that have been used toward their solution.
