Flow Characterization in the Santee Cave System in the Chapel Branch Creek Watershed, Upper Coastal Plain of South Carolina, USA

Karst watersheds possess both diffuse and conduit flow and varying degrees of connectivity between surface and groundwater over spatial scales that result in complex hydrology and contaminant transport processes. The flow regime and surface-groundwater connection must be properly identified and characterized to improve management in karst watersheds with impaired water bodies, such as the Chapel Branch Creek, South Carolina watershed, which has a long-term sampling station presently listed on an EPA 303(d) list for phosphorous, pH, and nitrogen. These measurements indicated that, the conduit flow to Santee Cave spring was recharged predominantly from diffuse flow, with a slow response of surface water infiltration to the conduit. Methods described herein to characterize the flow type and surface-groundwater connection in the Santee Cave system can be applied not only to watershed management in the Chapel Branch Creek watershed, but also to the greater region where this carbonate limestone aquifer exists.