Linking water quality and beach morphodynamics in a heavily impacted tidal creek in Myrtle Beach, South Carolina

The morphological changes of small tidal creeks, driven by coastal processes, can pose risks to infrastructure and engineered coastlines and often rely on dredging to maintain them. These changes along the beachface can negatively affect the health of associated estuaries where open exchange between the ocean and creek basins is vital. This study used Real Time Kinematic-Differential Global Positioning System equipment to survey a small tidal creek in Myrtle Beach, South Carolina that often experiences migration to the south and requires dredging to maintain an open exchange between the ocean and the estuary. In order to understand the relationships between the geomorphology of the beachface and the water quality within the creek basin, various geomorphic features were extracted from topographic surfaces using ArcGIS. Our results revealed that net sediment deposition had a strong correlation to changes in the Singleton Swash Tidal Range/Ocean Tidal Range ratio. These results suggest a reduction in tidal currents, caused by the restricted tidal range, may lead to a more stratified water column, having implications for ecosystem health in the swash basin. Dredging, which reduced the elevation in the creek channel, was immediately followed by an increase in the SSTR/OTR ratio; re-establishing open exchange with the ocean. While a permanent engineered solution is planned for Singleton Swash, this study provides insight into the dynamics of Singleton Swash in its natural state.