Water Samples Provide Further Guidance on How Best to Protect Water Quality at Stream Crossings in Piedmont Forests
Previous studies have examined the effectiveness of Best Management Practices (BMPs) in protecting forest streams in North Carolina’s mountains and coastal plain, but data from the region in between—the Piedmont—have been lacking. In partnership with North Carolina Forest Service, scientists from the Eastern Threat Center led a study to quantify sediment loads at Piedmont forest harvesting operations with a variety of soil types, watershed sizes, and road and trail slopes approaching stream crossings. Researchers measured sediment in 808 water samples upstream and downstream of stream crossing sites before, during, and after harvesting operations. The researchers found sediment concentration ranged from 56 milligrams per liter to 127 milligrams per liter across sites. Although these concentrations are low and will not harm aquatic species, results from this type of Piedmont study that defines the range of stream sediment variability at road and skid trail crossings are needed to adequately address water quality and sediment export concerns, and to help further refine statewide BMP guidelines. Results also assure forest managers that BMPs applied at stream crossings are part of sustainable operations that can provide forest products for people now and in the future while simultaneously protecting forest ecosystems.
Pictured: Researchers measured sediment in water samples upstream and downstream of stream crossing sites, such as this steel bridgemat at a skid trail crossing, before, during, and after harvesting operations. Photo by Neil Williams, U.S. Forest Service.
External Partners/Collaborators: North Carolina Forest Service; Duke University; North Carolina State University; General Electric; Orange Water and Sewer Authority; Montgomery County, North Carolina