Parts of the East Branch Mahoning Creek basin, a forested area of 29.6 square miles in west-central Pennsylvania, are disturbed by farming, surface mining, unpaved haul roads, eroding reclaimed areas, and logging. Streamflow was measured and water samples collected at a site upstream from the mouth from June 1979 to June 1980 during base flow and storm periods to evaluate sediment discharges. An additional site on a tributary draining mostly farmland was sampled from December 1979 to June 1980. Samples were analyzed for suspended sediment, turbidity, and specific conductance. Daily mean suspended-sediment concentrations and discharges were computed.
From June 1979 to June 1980, 3,570 tons of suspended sediment was transported from the basin. This was an average yield of 121 tons per square mile per year. From December 1979 to June 1980, a tributary draining 2.21 square miles of a predominantly agricultural area discharged 328 tons of sediment which was 12 percent of the sediment load transported from the entire basin.
Monthly sediment discharges averaged 298 tons ranged from 32 tons in July to 1,250 tons in March. The highest daily mean suspended-sediment concentration was 712 milligrams per liter on June 8, 1980. On that date, 267 tons of sediment was discharged from the basin.
