Through a series of sand box experiments, we studied the lateral movement of a red dye in and above a water table. The sand box was 103 cm long, 57 cm high, and 3 cm thick. Pressure transducers were used to measure pressure heads at 48 locations. Dye movement was recorded using digital images. In a rainfall experiment, we found that in the absence of rainfall, lateral migration of the dye occurred only in the capillary fringe. The dye did not infiltrate below the water table. However, under rainfall, the dye accelerated and moved rapidly into the groundwater. In an evaporation experiment, we found that dye migration slowed, but the scope of the pollution plume widened. Using this data, we developed a 2-D HYDRUS model.