The surficial aquifer within Miami-Dade County, Florida is characterized by very high transmissivity, secondary porosities and a strong degree of hydraulic interaction between ground water and surface water. The South Florida Water Management District (SFWMD) has constructed an integrated ground water / surface water model of the Miami-Dade county area using a finite volume based code developed by SFWMD. Such a model is highly parameterized and requires history matching to ground water levels, canal stages and canal flows. The automated calibration code PEST was applied in the history matching effort in order to evaluate the relative importance of each parameter and the correlation between parameters. The parameters adjusted included hydraulic conductivity, levee seepage coefficients, cana leakance and channel roughness. The application of such an automated calibration technique proved to be quite challenging due to the number of parameters as well as the nonlinear nature of the model. Nonetheless, good results were achieved in minimizing both Bias and RMSE of computed ground water levels and canal stages. Although satisfactory, automated history matching to measured canal flows was not as successful. It was concluded that automated calibration techniques can be successfully applied to an integrated surface water / ground water model at the scale and resolution inherent to this effort.