INVESTIGATING POSSIBLE STRUCTURAL CONTROL ON THE INTERACTION OF SURFACE AND GROUND WATER AT A SITE ON THE GEORGIA COASTAL PLAIN

This investigation seeks to determine whether structural controls are affecting the movement of ground water and surface water along a tidally-influenced river on the southeastern Coastal Plain in Georgia. The study site is located 56 river kilometers from the coast on a floodplain at the confluence of the Ogeechee and Canoochee rivers. Field mapping shows that tributaries draining the tidally-influenced wetlands at the confluence of the two rivers exhibit a strong rectangular drainage pattern. Also, clearly visible on aerial photographs of the site is a 1.1 kilometer long lineament running through the forested wetlands. This lineament also happens to coincide with an unusually straight segment of the Canoochee River; behind which is what appears to be a series of compressed meanders. Based on the rectangular drainage pattern, lineament, and compressed meanders it is hypothesized that surface and ground water at the site is structurally controlled.

Currently, a series of shallow monitoring wells are being installed in a transect across the lineament in order to try and detect possible changes in ground water chemistry or hydraulic head that may indicate structural influence. Head data will collected hourly using data loggers whereas water samples will be collected monthly and analyzed for general chemistry in a lab via ion chromatography. Temperature, pH, dissolved oxygen, and electrical conductivity of the samples will be measured in the field.