From civilizations to cities, water has played a key role. Water is one of the basic human needs. Its availability in the urban areas and in particular mega-cities gets constrained by the huge population residing in them. The mega-cities are confronted with the range of water issues due to the extreme spatial concentration of population. The book gives a comparative picture of three mega-cities of India, Delhi, Mumbai and Bangalore. These have been selected for their different geographical locations as it has a bearing on their water availability. The study focuses on the issues related to water. These problems varies in the three cities under study due to the contrast in their geographical location, geomorphology and urban hydrology. The three have noticed array of water issues. The water challenges for the cities include not only quantitative water shortages,but also deteriorating water quality, distributional problems and expanding water sources. Both the demand-side and the supply-side strategies can be used to address these water issues and contribute towards sustainable water situation.