Changes in the Availability of Freshwater Along the South Carolina and Georgia Coast Due to Potential Climate Change Scenarios

Saltwater intrusion into freshwater aquifers and drainage basins can threaten freshwater habitats, the biodiversity of freshwater tidal marshes, and the contamination of municipal, industrial, and agricultural water supplies.  The balance between hydrological flow conditions within a coastal drainage basin and sea level governs the magnitude, duration, and frequency of salinity intrusion into coastal rivers.  Future climate change is likely to aggravate the problems of salinity intrusion in the East Coast of the U.S., as increased air temperatures, changes in regional precipitation regimes, and potential sea-level rise alter these hydrologic balances.  This study examines saltwater intrusion on the Atlantic Intracoastal Waterway and the Waccamaw River by Myrtle Beach, SC and the Savannah River near Savannah, GA. Salinity intrusion results from the interaction of three principal forces - streamflow, mean tidal water-levels, and tidal range. To analyze, model, and simulate hydrodynamic behaviors at critical coastal gage locations, data-mining techniques, include artificial neural network models, were applied to over twenty years of hourly streamflow, coastal water-quality, and water-level data.  The study illustrates how future sea-level rise and a reduction in streamflows can potentially affect salinity intrusion and threaten the biodiversity of freshwater tidal marshes and municipal water supply.