Downstream zone of Mae-On Watershed has the main factors and causes from the drainage system network did not have a efficacy because of another river which is outside Mae-On river basin has converged to lower Mae-On River, which has the restrictive and shoal meander and along with promoting factors in land utilization, which has expanded without direction until the invasion area river. Transport network overlap drainage system. Areas receiving water decreases due to the development of the agricultural area for a residential area, the dam doesn’t have the gate open and close make the flood overflowing the river bank and cannot Drainage from the area make Spoilage Foulest and the spread of germs. The solution and alleviate the severity of floods have to adding a water distribution system to distribute water and improve river conditions to support quantity of water and make it flowing through during the rainy season and management land or land use zones in order to prevent the encroachment river catchment area.