BEAVER INFLUENCES ON CHANNEL PROFILE AND ECOSYSTEM HEALTH WITHIN THE NORTH CAROLINA PIEDMONT

Streams across the Piedmont of North Carolina have been impacted by historic land-use alterations. Post-European settlement agricultural practices led to the aggradation of large volumes of sediment along valley bottoms.. Today, these “legacy” sediments have left streams impaired, incised, and no longer able to support the aquatic ecosystems they once did. The purpose of our research was to investigate how beaver impoundments contribute to stabilizing and restoring stream channels in the North Carolina Piedmont. We compared two stream reaches along Miery Branch Creek, a tributary of Historic Yates Mill Pond. We conducted a Rosgen stream classification, Pfankuch Stream Stability assessment, and Bank Erosion Hazard Index (BEHI) estimate for these two sites. The Rosgen assessment revealed that there were two different stream profile classifications for both sites. Results from the Pfankuch stream stability test indicated a healthy stream assessment down-stream close to the beaver dam, while a less healthy assessment up-stream. The BEHI estimate also indicated that up-stream banks were high on the hazard index while the down-stream banks were significantly lower. From our results, we interpret that the presence of a beaver impoundment has had an overall positive impact on the stream by allowing the aggradation of sediments within the channel. Our results also indicate that after beaver dam breaches, channels were not incising in previously established beaver dam sediments. We conclude that the introduction of beavers into unstable, incised stream channels could potentially restore the stream and surrounding ecosystem.