It is difficult to perceive of life without water. Hence the availability of water, in right quantity and quality, is essential for the survival of human civilization. Oceans represent ninety seven percent of total water on earth, but the seawater is not directly usable. The balance three percent consists of freshwater, but again most of it is frozen ice in the arctic poles or in the glaciers on the mountain. Only three percent of total freshwater that flows in the rivers, lakes, and swamps are available to human use. Water being so vital for life to grow food, to run industries and to save the environment, the sustainability of water resources must be reviewed and strategised with a global overview. Thus, the concern for water is now very widely shared among all nations of the world in the impending scenario of global warming. Hence, the readership should likely be distributed among the environmental activists to the national and international policy makers, including all enlightened citizenry of the world. Universities, research institutions and socially-inspired NGOs and students at graduate and undergaduate levels will find much food for thoughts in this strategic review of global water resources.