Water is an important or perhaps the most important natural resource for survival of life on the earth. Geographical area of India is 3.29 million km2, which is only 2.4% of total geographical area of the world and has only 4% share of the world fresh water to support over 16% of the world population. India receives annual average rainfall of about 119 cm, which is highly variable temporally and spatially. Maximum rainfall received during three to four monsoon months is spatially highly variable. The areas receiving heavy rainfall during monsoon months invariably face water scarcity during the nonrainy season every year. Therefore, it is absolutely essential that every drop of water is conserved and efficiently used for long-term sustainability of scarce water resource for survival of mankind.