This book provides an insight on the importance of lakes in urban area. it highlights the role played by these lentic water bodies in maintaining the ecological balance of the earth system. Lakes can provide us with prime opportunities for recreation, tourism, and cottage or residential living. The present investigation has been carried out with a focus to evaluate comparatively the prevailing water quality and potability of two lakes, Malathalli lake (viz., sewage fed lake) and Sankey tank (viz., rainfed lake) in addition to groundwater samples around these two lakes by analyzing physico-chemical and biological parameters in addition to radon estimation in both surface and groundwater samples. Further, effort has been made to understand the effect of urbanization and anthropogenic pressure on lake water quality, the study has been stressed on Sankey tank which lies in highly urbanized and Malathalli Lake is situated less urbanized area.