ABSTRACTThe U.S. National Committee for the International Hydrological Decade is proposing a National Water Atlas as a contribution to the improvement of the quality of information available for this Nation's large‐scale planning and management studies. The atlas would provide hydrological maps of the United States and its principal basins and of its territories. The nationwide maps would be at a scale of 1:5,000,000 and the 17 principal basins at 1:2,500,000. The principal basins will be those delineated by the Water Resources Council. Wherever feasible and appropriate, the data will be presented with a common standard period of record, preferably 1941–70, as a base. Map subjects would include station networks, radiation, precipitation, snow and ice, evaporation, atmospheric vapor fluxes, surface‐water discharge, ground‐water storage and discharge, chemical quality, sediment discharge, water temperatures, and soil moisture. The list of maps subjects and types of data shown within each subject are flexible and open‐ended so that additional maps could be added to the atlas as information is available or as new ne