The tidal marsh connects terrestrial landscapes with the coastal ocean. Groundwater within this environment has the ability to move nutrients and influence plant distribution. Land-use change and Sea Level Rise (SLR) threaten to change these groundwater patterns. Monitoring wells recording conductivity, temperature, and water level across a back barrier island-marsh transect at Sapelo Island, GA, identified drivers of groundwater flow. Pressure propagation from tidal variations in creek water level was negligible at the study site. Density-driven flow had little impact on groundwater movement. The saturated nature of the marsh allowed for the well nearest the tidal creek to be used as an inundation meter, and the effect of tidal flooding was identified using three different techniques. Filtering the tidal signal record demonstrated that precipitation, was a main factor for water level changes in the well nearest the upland.