ANALYSIS OF THE SUB-SURFACE HYDROLOGY OF CAROLINA BAYS AT THE SAVANNAH RIVER SITE, SOUTH CAROLINA

Carolina Bays are shallow, elliptical lakes that occur along the southeastern coastal plain of the United States, primarily in the states of Georgia, South Carolina and North Carolina. While the origin of these conspicuous features has long been the subject of controversy, the characterization of the groundwater flow fields around these water bodies is also not well understood. Much of the research conducted to date appears to focus on bays that occur at lower elevations within the lower Coastal Plain where these bays appear to be surface water expressions of the regional water table. The extent to which these bays are in hydraulic connection with the regional groundwater system is an issue of interest at the Savannah River Site (SRS). The SRS, a 320 square mile facility operated by the Department of Energy is situated within the upper Coastal Plain at elevations ranging from 100-350 ft. above mean sea level. A survey of the Carolina Bays occurring at the SRS indicates that the majority of these bays occur at elevations significantly higher than the regional water table although some lower-lying bays are likely a surface reflection of the water table. Some of the bays are dry and accumulate standing water only in the wettest of times. ArcGIS was employed to locate hundreds of Carolina Bays at SRS and to classify them with respect to the likelihood they are in hydraulic connection with the regional groundwater flow system. Additionally, long-term records of water level fluctuations in selected lakes were utilized to assess the degree of inter-connection. These results will guide acquisition of additional sub-surface data to demonstrate the degree of hydraulic connection.