Surface-water information is needed for purposes of surveillance, planning, design, hazard warning, operation, and management in water-related fields such as water supply, hydroelectric power, flood control, irrigation, bridge and culvert design, wildlife management, pollution abatement, flood-plain management, and water-resources development. An appropriate data base is necessary to provide this information.Objectives: (1) To collect surface-water data sufficient to satisfy needs for current uses, such as assessment of water resources, operation of reservoirs or industries, forecasting, disposal of wastes and control of pollution, and research or special studies. (2) To collect data necessary for'analytical studies to define the statistical properties and trends in rainfall, streamflow, water levels, and water quality.Approach: Standard methods of data collection are used as described in the USGS publications series "Techniques of Water-Resources Investigations of the United States Geological Survey." Partial-record gaging is used instead of complete-record gaging where it serves the required purpose. The network includes continuous and intermittent discharge stations (fig. 3), stage-only and lake stage stations (fig. 4), and peak or crest stage stations (fig. 5).Progress: The surface-water network has grown to include operation and annual publishing of hydrologic data from 120 continuous-gaging stations, 22 stage only stream stations, and 13 lake-stage stations. Miscellaneous measurement data from 4 sites and data from 41 crest-stage partial-record stations are also published. Thirty-one raingages also are operated within the network.