A STREAM CATENA: COLLABORATIVE RESEARCH AND MONITORING IN A TIDAL SYSTEM FROM FORESTED WETLAND HEADWATERS TO THE CHARLESTON ESTUARY

Tidal freshwater wetlands are important ecosystems at the interface between terrestrial and marine environments. The upper end of the catena of terrestrial and estuarine systems are tidal freshwater forested wetlands (TFFWs), the floodplain settings of the inland extent of the tidal range. In the low relief coastal plains of the Atlantic and Gulf Coast of the United States, tides can influence the hydrology dozens of kilometers inland. We are studying a portion of the Charleston (SC) estuary, the East Branch of the Cooper River and its upstream component, Huger Creek which is the receiving stream of about 185 km² of the freshwater wetland-dominated Francis Marion National Forest. For this study we are examining the hydrology, nutrient concentrations, and environmental parameters in a freshwater tidal stream. The goal is to estimate the relative contributions to stream volumes from storm runoff and baseflow in this tidal system to better understand hydrology influences on biogeochemistry in the stream and floodplain wetlands. Freshwater discharge increased as the tidal range decreased, as expected but stream stage and discharge dynamics under different tidal and outflow conditions (e.g., post-storm events, winter [higher flows], and summer [lower flows]) are being assessed with one objective to develop a rating curve for this site. We will also share information about the process of establishing the tidal stream gaging system to its full operation that has involved collaborative relationships with several stakeholders including multiple federal agencies, a university, a water technology company, and the research consortium WHONDRS.