Sediment loads, discharges, and yields in the East Branch Mahoning Creek basin, Clearfield and Jefferson Counties, Pennsylvania, June 1979 through September 1981

Rainfall, streamflow, and sediment discharge data were collected from the East Branch Mahoning Creek basin from June 1979 through September 1981 to evaluate sediment discharges from an area in which erosion and sediment controls were being used on surface mined areas. Sediment yields from the basin averaged 144 tons/sq mi/year. During the study, 9,570 tons of sediment were transported from the East Branch Mahoning Creek basin. Increased monthly suspended-sediment loads were found after July 1980 when mined-area reclamation was accelerated. Beaver Run near Troutville discharged 576 tons of sediment, which was 7% of the load transported from the basin from December 1979 through September 1981. Turbidity and suspended-sediment concentration follow a linear relation throughout the range of measured values. Using this relation and the frequency distribution of suspended-sediment concentrations, the estimated turbidity levels in the stream were equal to or greater than 30 Nephelometric Turbidity Units (the level at which the streams become unusable as a public water source) approximately 15% of the time during the study. (USGS)