Water Resources:

Water, as you know, is the most essential component of  life. Our water resources are limited,  though apparently, water is available in an abundant quantity. There is scarcity of usable quality of water in  large parts of  the world. You will be quite amazed to know  that only 2.7% of the total water resources of the earth consist of fresh water, fit for drinking, irrigation and such other purposes. Water flowing in  the streams and rivers is only 0.0001% of  the total water resource on the earth, i.e., one bucket  in  10,000 buckets! Fresh water lakes contain only 0.009%  of  total water. Ground water upto a depth of  about 150 metres accounts for only 0.625%. Water found in the frozen state as snow on high mountains, which cannot be directly used, accounts  for about 2.15%. 

The total volume of water found in underground reservoirs, called aquifers, which can be pumped out is estimated  to bi: 42.3 x 10¹⁰%cbic metres, of which only a quarter is being used, and the rest can be utilised  in future for irrigation, industries and homes etc. The hydrological map of  India given here shows that there are many regions of  the country, such as parts of Andhra Pradesh and Tamil Nadu, which have a low ground water potential.

That is, the amount of ground water is  in  small quantity in these regions. From the above, we can cee that water which is required for various purposes like irrigation, navigation, generation of hydro-electricity  and domestic and industrial needs is rather scarce. It is, therefore, necessary that water resources should be exploited judiciously.