Management Practices for Sediment Reduction from Forest Roads in the Coastal Plains

Sediment has been identified as one of the most important non-point source pollutants of surface waters. In forested areas, the predominant source of sediment is from the construction and maintenance of access roads, which contribute as much as 90% of the total eroded sediments. Seven different road management practices were studied to determine their effectiveness in reducing sediment production from forest roads on nearly flat lands in the lower coastal plains of North Carolina. One practice utilized a continuous berm along the roadside, while the other six practices had a non-continuous berm with different combinations of road surface gravel and roadside vegetative strips. Runoff samples collected during eleven different rainfall events of varying intensity and duration were analyzed for sediment content. The rainfall amount, intensity, infiltration, and antecedent rainfall conditions were combined into a single energy rating to assist in the overall analysis. The results of the study showed that a continuous berm maintained along the edge of a forest road can reduce total sediment loss by an average of 99% compared to the same type road without the presence of a continuous berm. When a continuous berm is not present, graveling the road surface can reduce the total loss of sediment from roads by an average of 61% compared to a non-graveled road surface. A 90 cm wide grass strip on the edge of the driving surface can reduce total sediment loss by an average of 56% compared to a road without a grass strip.