The Geological Survey has been the foremost agency in the investigation of ground‐water resources in the United States beginning about 1910. Most of the basic principles of modern ground‐water hydrology were developed in the Survey's program of cooperative investigations. Use of ground water in the United States in 1960 was about 17½ percent of all water uses, excluding water power. The use will probably increase, though at a decreasing rate. Although amount of use may level off, the need to know about it will not. While coordinating its activities with those of the Office of Water Data Coordination and the Office of Water Resources Research, the Survey expects to step up its work in all three areas of data collection, investigations, and research. However, there will be changes of emphasis. Collection of raw data will tend to stress key observation points, and more and more observation of temperature and quality, including contaminants. Investigations will be aimed at upgrading reconnaissance coverage to general coverage for most of the Nation. The areal basis will be stream drainage basins and special hydrologic terranes, rather than political units. There will be an increase in the preparation of analog models for representative ground‐water systems. In research, the problem‐oriented basis will continue. Stress will be on basic principles that pertain to artificial recharge, and the natural recharge and discharge of ground‐water reservoirs; and also on the application of geologic principles on a regional scale. These are critical elements in the management of surface‐water and ground‐water resources conjunctively in river basins.