Importance of Water for the livelihood of human beings is inevitable. This study is carried out to perceive the impact of ever increasing urbanization in the catchment of Rawal Lake inflows and quality of Water. Rawal Lake is constructed on Korang River and supplies water for domestic use to Rawalpindi city and Cantonment Area. The results argues that the urbanization in the catchment is increasing with a very high % specially the population in the last eleven years has increased up to 85% at a growth rate of 5.7%, while the built up land has increased 9%. On the other hand area under forest has decreased up to 10%. As a result of enhance in urbanization flows have decreased even though there is no major transform noticed in rainfall which is evident that urbanization has decreased the flows. Urbanization also has an adverse effect on quality of water which is found biologically unfit for human consumption. It has also contributed to the amount of suspended sediment in the flows.