In the recent past, in many developing countries a good deal of research has been carried to solve the problems of ‘large basins’ whereas not much has been done with regard to the hydrologic problems of small watersheds. Small watersheds to play important roles e.g. a village pond catered by its own small watershed; in hilly watersheds, the generated runoff causes flash flood, resulting into disruptions of communication lines etc. Therefore, it is necessary to look into these aspects of the hydrologic problems with greater attention. The hydrologic responses of a small watershed depend upon the mechanics of surface runoff, which is primarily a nonlinear process. We have discussed the sensitivity of physiographic parameters through lumped kinematics wave models and found that the overland roughness and overland slope are more sensitive than other physiographic parameters of overland and channel flows. Appropriate discussions of results and conclusions as arrived at in different parts have been summarized.