FIELD-BASED ASSESSMENT OF AN URBANIZED MOUNTANE HEADWATER CATCHMENT: THE IMPACT OF WATERSHED-WIDE GREEN STORMWATER INFRASTRUCTURE RETROFITS

Abstract

Most stormwater research in the southeastern US has occurred near the major academic research institutions located within the Piedmont. As a result, performance standards and design guidelines for green stormwater infrastructure (GSI) and other types of stormwater control measures (SCMs) do not readily transfer to the steep mountain environment, which is characterized by shallow soils, steep gradients, and intense rainfall. To provide insight into regionally-specific performance standards and design guidelines for GSI and SCMs, the authors helped to establish an experimental watershed in Asheville, NC. Storm event measurements of creek stage, discharge, and sediment concentration were collected within a first-order mountain stream draining approximately 100 acres of developed headwaters. These measurements were collected before and after the construction of six green stormwater infrastructure (GSI) retrofits upstream throughout the watershed. The experimental watershed is fully contained within the campus of Givens Estates, a retirement community of the United Methodist Church. The project is funded by the NC Clean Water Management Trust Fund, and the project is sponsored by RiverLink, an Asheville-based non-profit dedicated to promoting the environmental and economic vitality of the French Broad River and its watershed. In this presentation the authors will provide an overview of the experimental watershed and project history, outline the goals of the grant-funded project, and present data from storm event measurements before and after implantation of GSI retrofits. The authors will also describe the applicability of the research, and how the lessons learned through this project can benefit the design of GSI projects in the difficult montane landscapes of the Southern Appalachians.