Abstract Water requirements of the USA and their impact on the need for desalting are presented. The study uses data from preliminary figures of the 1975 Water Assessment of the US Water Resources Council. The potential for great increases in desalting exists because of the large and increasing water requirements for industrial, municipal and energy uses. At the same time, water scarcity and pollution limits will require increasing reuse of water. The reuse of water and turning to brackish and ocean water to supplement scarce local supplies of fresh water will require additional desalting.