Implementation of Forestry Best Management Practices and Sediment Delivery in Three Regions of North Carolina and Virginia

Forestry best management practices (BMPs) were created in response to the Clean Water Act of 1972 to protect water quality from nonpoint source pollutants such as sediment. The objectives of this study were to quantify the relationship between BMP implementation and sediment delivery on 58 recently harvested sites across three physiographic regions and five forest operational features. BMP implementation rates, erosion rates, sediment delivery ratios, and sediment masses were calculated at 183 silt fences functioning as sediment traps adjacent to streams in Virginia and North Carolina. Major access system features, including stream crossings, skid trails, and haul roads, typically delivered the greatest sediment mass to streams and had the highest sediment delivery ratios on a per feature basis. When accounting for sediment mass delivered and area in each feature, harvest area accounted for approximately 70% of sediment delivered to streams for all regions. Most features had proportionally higher erosion rates than sediment masses collected at silt fences, indicating that most erosion generated by forest operations is being trapped by either harvest areas or streamside management zones. For most features and regions, as BMP implementation increased, erosion rates and the sediment masses delivered to streams decreased. Study Implications Forestry best management practices (BMPs) are designed to mitigate the amount of sediment entering streams and affecting other aquatic features as a result of forest operations. In this study, a significant inverse relationship between BMP implementation and the amount of sediment delivered to streams was found, indicating that increasing levels of BMP implementation reduces sediment delivery. Most of the erosion caused by forest operations is being trapped before it is delivered to streams. This research highlights the importance of leaving streamside management zones along streams and minimizing the extent of bare soil and area in temporary and permanent roads.

Protecting Water Resources with Streamside Management Zones at Robinson Forest

Streamside management zones (SMZ) are a common best management practice used to minimize impacts to water quality from forest harvesting. Information on the effectiveness of SMZ use in Kentucky is limited. Moreover, details on SMZ configuration (size, layout, canopy retention) is lacking. The objective of this research was to evaluate the impact of varying SMZ configurations on stream ecosystem function. Results indicated that the use of elevated stream crossings and maximizing the amount of undisturbed forest floor near streams via a combination of increased SMZ width and canopy retention was effective at minimizing water quality impacts from forest harvesting.