Fresh water is a natural resource of fundamental importance. Without water life is not possible. In many respects the properties of water are unique. They seem to be especially designed for the living organisms. No other liquid can replace it.

(I) Global Distribution of Fresh Water

We have a huge quantity of fresh water on our planet, almost 1500 million cubic kms (Penman 1970), but most of it is useless for us as it contains too much of salt. Total amount of available fresh water on our planet is only about 84.4 million cubic kms. The global distribution of fresh water on earth’s crust including ground water and water present as vapours in the atmosphere.

Much of the water on earth’s surface and ground water represents deposits which have accumulated over a long period of time. If input via precipitation exceeds the output, small amounts of fresh water accumulate as left over stock in ice-deposits, lakes and reservoirs or under the ground surface. This is, however, a reserve stock. Withdrawal of fresh water from this stock, howsoever large the deposit may be, tends to disturb the natural system and the resource base in the long run and is detrimental to the environment.

Global distribution of fresh water.


Water as Cubic Kms.


Water in snow-caps, Ice sheets, glaciers etc.



Surface ponds, lakes and reservoirs



Water in streams and rivers



Water present as soil moisture



Ground water


Total amount of fresh water on our planet 84,366,200