ISOLATING THE IMPACTS OF A DISTURBED, EPHEMERAL GULLY ON WATER QUALITY AND STREAM ECOLOGY IN A HEADWATER CATCHMENT IN WESTERN NORTH CAROLINA

A growing body of evidence suggests contributions to runoff from ephemeral channels during events can exhibit significant control over water quality in higher-order streams. Field observations from a steep Appalachian catchment influenced by human activity suggest these disturbed ephemeral drainages exhibit significant control over turbidity, water temperature, and conductivity levels downstream. High turbidity during stormflow is a water quality problem in many areas of the Southern Appalachians. However, upland ephemeral channels are not included in the jurisdiction of the Clean Water Act. This offers little recourse if their contributions degrade the water quality of larger streams and highlights the need for robust evidence of the potential impacts resulting from ephemeral drainages. The aim of this study is to isolate the contribution of a disturbed ephemeral channel by diverting its flow from the study-stream network. Spatially and temporally distributed stream-water samples taken during storms, when the channel is diverted or allowed to flow normally, will allow us to assess its effects on water quality. Additionally, stream macroinvertebrate surveys will aid in linking water quality changes to ecological impacts. Initial results indicate this ephemeral channel is impacting concentrations of major ions, turbidity, and nutrients in the perennial stream. We anticipate the findings of this study will be relevant to describing water quality and ecological impacts of disturbed ephemeral channels and will aid in evaluating their potential influence on other water chemistry parameters downstream.