The continuing growth of urban areas that replace farm lands and forests with paved areas and structures inevitably brings about changes in watershed physical parameters such as surface slope, roughness and infiltration rates. The effects of these changes, which result in increased volume and peak rate of runoff that often cause tremendous damage to life and properties, needs to be better understood. The present study proposed a mathematical model, based on kinematic wave theory, to evaluate the effects of urbanization on peak flows for small areas. This model takes into account the spatial variations of slope, roughness, slope-length, rain-excess intensity and duration. Computer programs for watershed profiles having two and three sections with different parameters were written for computing peak overland flow under various conditions. (Modified author abstracts)