Ground water mounds and a water table depression, relative to the adjacent river stage, are evident and the spatial area and relative height differences are consistent over time. Variability in river stage and precipitation events did not significantly alter the potentiometric surface features, reducing the importance of infiltration recharge alone. An application of the numerical code TOUGH2 was developed to simulate saturated and unsaturated flow patterns and heat transport within the channel bar. Additionally, a multi-component analysis was completed that synthesized flow patterns, water quality, geochemical analysis, microbial analysis, and heat tracing in an effort to determine the physical mechanisms for ground water mounding.

We present several possibilities for processes that may induce the water table features and suggest that non-Darcian flow patterns may be responsible. These potentiometric surface features may have a significant impact on nutrient dynamics within the subsurface. These effects are realized when the localized variances in water quality and chemistry occur with flux into the surface water.