This study investigates flood generations on urban watershed by synthesising land use dynamics and climate change. It developed a GIS base Precpitation Water Inundation Model PWIM for peak flow and area inundation analysis. The land use dynamics of system 6c reveals that the built up area progressively increased on the watershed from about 166.88 hectares (12.40%) in 1965 to 1231.00 hectares (91.46%) in 2003 at an average rate of 28.00 hectares per annum. The climate change study reveals that urban flooding will be more severe in the first 20 to 30 years, using year 2003 urbanization driver as the base year, and that peak flow and other related velocity for the 25years high climate change will increase by an average of 16.1% while inundation area will increase by an average of 2.46%. Policy implementations that embrace the use of the PWIM for design and urban renewal purposes, upscaling flood control design measures by 20% to incorporate estimated future flood due to climate change phenomenon, awareness and improving the socio- economic status of the vulnerable individual were recommended.