Cattle ponds are commonly used for cooling livestock and for irrigation. Levels of bacteria Escherichia coli in water characterize water quality. We developed the model of fate and transport of E. coli using the HydroGeoshere modeling platform. Pond surface was imaged to estimate the E. coli load to the pond from animals in water. This work shows the opportunity and the approach to obtaining a moderately accurate forecast of microbial water quality in cattle ponds using readily available data.