The application of a climatic water balance model is shown to be useful in the estimation of representative regional precipitation. Often the precipitation recording network does not accurately represent the average conditions of a region due to gage height, exposure, and the degree to which the individual sample points represent true variations in precipitation. A comparison of calculated and measured regional runoff is made to assess inaccuracies in the measured hydrologic regime of the study area in western New York State. Discrepancies between calculated and measured runoff are shown to be related to problems of precipitation measurement, producing a consistent gage undercatch. It is shown that a water balance model might be used to adjust regional precipitation values to better represent the average condition over the total region.