This paper emphasizes the probable degree of magnitude of the anticipated demand for water in the United States. The over-all availability of water in the United States is compared with the major domestic, agricultural, and industrial demands made on the supply. It ventures to predict future demands in conformity with past and present trends of use. Because many uses and demands are neglected, the paper is not designed to be comprehensive in scope. It is designed to evoke discussion of the implications inherent in the apparent adverse balance between supply and probable demand, and to engender recommendations for present and future action to prevent exhaustion of the supply.