WATER RESOURCES OF INDIA

Water is a primary natural resource, a basic human need and a precious national asset. Water is critical to our daily lives and a principal compound in nature. A human can survive 50 to 60 days without food, but only 2 or 3 days without water. The water we use must be adequate in quantity as well as quality for its many tasks—everything from personal hygiene to vast national water projects. Water indeed occupies that place between land and sky, mediating energy and shaping both, the lithosphere and atmosphere. The significane of water is increasing with the tremendous increase in population. We need water for drinking, personal hygiene, domestic, consumption, irrigation, industrial purposes, generation of hydel-power, transport and recreation.

The average annual water availability of the country is assessed at 1869 billion cubic metres (BCM). Of this, total utilisable water resource is assessed at 1123 BCM; surface water 690 BCM and ground water 433 BCM. The per capita availability of water at the national level has been reduced from about 5177 cubic metres in 1951 to the estimated level of cubic metres in 2012 with variation in water availability in different river basins.

There are two main sources of water, i.e. (i) the surface water, and (ii) the underground water. According to Prof. K.L. Rao (1975), the total quantity of water annually carried by the rivers of the country is about 1,645,000 million cu m. The utilisation of water as estimated by Rao is given in Table 3.3.

Table 3.3 India's Water Utilisation by 2000 (in thousand million cubic metres)

Source: Rao, K.L. (1975); India’s Water Wealth.

It may be noted from Table 3.3 that about 77 per cent of the available water is used for irrigation purposes, 13 per cent for power generation, 3 per cent for industries and the remaining 6 per cent for domestic consumption.

According to one estimate the total ground water reserve up to a depth of 300 in is about 3700 mham, almost ten times of the annual rainfall. In terms of exploitation of ground water potential, Punjab comes on top (about 94%) followed by Haryana (84%), Tamil Nadu (61%), Rajasthan (51%), Gujarat (42%), Uttar Pradesh (38%), Maharashtra (31%), West Bengal (25%), and Andhra Pradesh (24%). States like Assam, Odisha, Madhya Pradesh, and Bihar have not been able to utilise even 20 per cent of their total ground water potential.

The main problems associated with the utilisation of water are: (a) high fluctuations in the regimes of rivers, (b) uneven spatial distribution of precipitation, (c) wastage of water during floods, (d) unscientific utilisation of water, (e) pollution of rivers, and (f) dispute on water distribution among the states.

India’s rivers are highly polluted. The rapid growth of population, agricultural modernization, industrialization and urbanization have reduced the per capita availability of water. The pollution of rivers, lakes and ponds have aggrevated the situations.