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Water Resources of India
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- India accounts for about 2.45 per cent of world’s surface area, 4 per cent of the world’s water resources and about 16 per cent of world’s population.
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Surface Water Resources
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- There are four major sources of surface water. These are rivers, lakes, ponds, and tanks.
- In the country, there are about 10,360 rivers and their tributaries longer than 1.6 km each. The mean annual flow in all the river basins in India is estimated to be 1,869 cubic km.
- Water flow in a river depends on size of its catchment area or river basin and rainfall within its catchment area.
- Much of the annual water flow in south Indian rivers like the Godavari, the Krishna, and the Kaveri has been harnessed, but it is yet to be done in the Brahmaputra and the Ganga basins.
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Groundwater Resources
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- The level of groundwater utilization is relatively high in the river basins lying in north-western region and parts of south India.
- The groundwater utilization is very high in the states of Punjab, Haryana, Rajasthan, and Tamil Nadu.
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Lagoons and Backwaters
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- India has a vast coastline and the coast is very indented in some states. Due to this, a number of lagoons and lakes have formed.
- The States like Kerala, Orissa and West Bengal have vast surface water resources in these lagoons and lakes.
- Although, water is generally brackish in this water -bodies, it is used for fishing and irrigating certain varieties of paddy crops, coconut.
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Water Demand and Utilization
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- India’s water demand at present is dominated by irrigational needs.
- Agriculture accounts for most of the surface and ground water utilization, it accounts for 89 per cent of the surface water and 92 per cent of the groundwater utilization.
- While the share of industrial sector is limited to 2 per cent of the surface water utilization and 5 per cent of the ground-water,
- The share of domestic sector is higher (9 per cent) in surface water utilization as compared to groundwater.
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Demand of Water for Irrigation
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- In agriculture, water is mainly used for irrigation. Irrigation is needed because of Spatio-temporal variability in rainfall in the country. The large tracts of the country are deficient in rainfall and are drought prone.
- Water need of certain crops also makes irrigation necessary. Water requirement of rice, sugarcane, jute, etc. is very high which can be met only through irrigation.
- Provision of irrigation makes multiple cropping possible. It has also been found that irrigated lands have higher agricultural productivity than un-irrigated land.
- the high yielding varieties of crops need regular moisture supply, which is made possible only by a developed irrigation systems.
- In fact, this is why that green revolution strategy of agriculture development in the country has largely been successful in Punjab, Haryana and western Uttar Pradesh.
- In Punjab, Haryana and Western Uttar Pradesh more than 85 per cent of their net sown area is under irrigation.
- Of the total net irrigated area 76.1 per cent in Punjab and 51.3 per cent in Haryana are irrigated through wells and tube wells. This shows that these states utilize large proportion of their ground water potential which has resulted in ground water depletion in these states.
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Emerging Water Problems
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- The per capita availability of water is dwindling day by day due to increase in population.
- The available water resources are also getting polluted with industrial, agricultural and domestic effluents, and this, in turn, is further limiting the availability of usable water resources.
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Deterioration of Water Quality
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- Water quality refers to purity of water, or water without unwanted foreign substances. Water gets polluted by foreign matters such as micro- organisms, chemicals, industrial and other wastes.
- The Ganga and the Yamuna are the two highly polluted rivers in the country Water Conservation and Management water availability from sea/ocean, due to high cost of desalinization, is considered negligible, India has to take quick steps and make effective policies and laws, and adopt effective measures for its conservation.
- Besides developing water saving technologies and methods, attempts are also to be made to prevent the pollution.
- There is need to encourage watershed development, rainwater harvesting, water recycling and reuse, and conjunctive use of water for sustaining water supply in long run.
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Recycle and Reuse of Water
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- Another way through which we can improve fresh water availability is by recycle and reuse.
- Use of water of lesser quality such as reclaimed waste-water would be an attractive option for industries for cooling and fire fighting to reduce their water cost.
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Watershed Management
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- Watershed management basically refers to efficient management and conservation of surface and groundwater resources.
- It involves prevention of runoff and storage and recharge of groundwater through various methods like percolation tanks recharge wells, etc.
- However, in broad sense watershed management includes conservation, regeneration and judicious use of all resources – natural (like land, water, plants and animals) and human with in a watershed.
- Watershed management aims at bringing about balance between natural resources on the one hand and society on the other. The success of watershed development largely depends upon community participation
- Haryali is a watershed development project sponsored by the Central Government which aims at enabling the rural population to conserve water for drinking, irrigation, fisheries and afforestation. The Project is being executed by Gram Panchayats with people’s participation.
- Neeru- Meeru (Water and You) programme (in Andhra Pradesh) and Arvary Pani Sansad (in Alwar, Rajasthan) have taken up constructions of various water-harvesting structures such as percolation tanks, dug out ponds (Johad), check dams, etc. through people’s participation.
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Rain water Harvesting
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- Rain water harvesting is a method to capture and store rainwater for various uses. It is also used to recharge groundwater aquifers.
- It is a low cost and eco-friendly technique for preserving every drop of water by guiding the rain water to bore well, pits and wells.
- Rainwater harvesting increases water availability, checks the declining ground water table, improves the quality of groundwater through dilution of contaminants like fluoride and nitrates, prevents soil erosion, and flooding and arrests salt water intrusion in coastal areas if used to recharge aquifers.
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