| Grade control and flow deflecting stream restoration structures are installed to constrain stream bank and bedform changes. This study assesses decadal changes in stream morphology around natural channel design (NCD)-based restoration structures in a sand and gravel-bed stream. Three sets of stream survey data were collected at four restoration sites along Onondaga Creek, in central New York. ArcGIS was used to track changes in thalweg and bank positions and determine locations of erosion and deposition through difference of DEMs. Results showed that following restoration: a) deposition occurred in over half of pools, runs, riffles, and glides; b) the stream narrowed throughout all reaches; c) erosion and deposition exhibit spatial patterns relative to structure type; d) restoration, especially toe slope protection, reduced some bank erosion but pattern changes still occurred. Understanding long-term morphology changes at NCD-based restoration sites furthers adaptive management goals, leading to improved designs. |
