Runoff and sediment losses from natural and man-made erosion control materials

Man-made erosion control materials are increasingly being used st construction sites. The performance of these materials in comparison to natural materials is largely unknown. A rainfall simulation study was designed in which four man-made materials (wood excelsior, jute fabric, coconut fiber blanket, and coconut strand mat) and two natural materials (straw and turfgrass sod) were evaluated. The erosion control materials were evaluated on a Sassafras loamy sand (fine loamy, mixed mesic Typic Hapludult) having a 8% slope and on a Sassafras sandy clay loam (fine, silty, mixed mesic Typic Hapludult) having a 14 to 21% slope. Disturbed soil surface areas (0.76 m(2) each) were covered with each material and subjected to a 96 mm hr(-1) simulated rainstorm. Runoff and sediment loss rates were determined every 5 min for 35 min after recording the time required for runoff initiation. Sod was the only material that extended the time required for runoff initiation. Runoff from all materials was less than bare soil for the first 5 min of runoff; however, only straw,jute, and sod reduced runoff over the entire storm event. The total amount of runoff, com pared with bare soil, was decreased by 61% for sod, 25% for straw, and 16% for jute. Erosion control materials reduced bare soil erosion by 80 to 99%. Of the man-made erosion control materials, only jute reduced runoff and sediment losses at both locations. Therefore, of the materials tested, only sod, straw, and jute would be expected to effectively reduce both runoff and sediment losses.