Subsurface geologic characterization beneath the lakes and rivers was determined by High Resolution Seismic Profiling (HRSP). The acoustic profiles provide images of karst features such as subsidence and collapse structures and related fracturing, faulting and dissolution pipes. These features may produce breaches within the confining layer or define subsurface discontinuities that provide a pathway for communication between surface waters and the aquifer. The physical parameters that produce these features, such as thickness of overburden, can also be inferred from HRSP with support from interpretations of gamma-log profiles obtained from water wells in the vicinity. Previous knowledge of geomorphology and regional geology further supports the HRSP and gamma-log interpretations. Compilation of HRSP from across north central Florida shows that certain karst-related features re-occur from lake to lake. By identifying these features, as well as comparing the subsurface physical parameters between lakes, the potential for interaction between surface and groundwater can be determined.