NEED FOR STUDY: Water-resource planning and water-quality assessment require a nationwide data base with standardized information. Sediment concentrations and discharges in rivers and streams need to be monitored and defined to achieve this goal. OBJECTIVES: To provide a national sediment data base for use in Federal programs and Federal management of interstate waters. The State also needs spatial and temporal averages and trends of sediment concentration, sediment discharge, and particle-size distribution of sediment being transported in the rivers and streams for planning and action programs.