Water Resources

Written and reviewed by Subhra Gupta, Humanities faculty at UniDrill (M.A. Sociology, University of Delhi · 7 years teaching Humanities). Based on NCERT Geography Class XII (India: People and Economy), Chapter 4.

Why is a land of great rivers short of water?

About 71 per cent of the earth's surface is covered with water, yet freshwater is only about 3 per cent of the total, and only a small part of that is within reach of people. India's position is sharper still. It holds about 2.45 per cent of the world's surface area, about 4 per cent of the world's water resources and more than 17 per cent of the world's population. Divide the water among the people and the per capita stress is built in before a single drop is wasted. Add uneven rainfall, pollution and heavy farm demand, and you get the problem this chapter is about.

From rain to usable water

Water is a cyclic resource, so it comes back every year. What matters for planning is how much of it you can actually put to use.

The arithmetic ties up: 690 plus 432 is 1,122.

Surface water

There are four sources: rivers, lakes, ponds and tanks. India has about 10,360 rivers and tributaries, each longer than 1.6 km. A river's flow depends on the size of its catchment (its basin) and on the rainfall inside it. Rainfall is also highly uneven across space and falls mainly in the monsoon, so even large rivers carry water that cannot all be used.

Pause and predict: the Ganga, Brahmaputra and Barak basins cover only about one third of India's area. Do you expect them to hold more or less than one third of its surface water?

Check your answer: more. They hold about 60 per cent, because their catchments are huge and rainfall in them is relatively high. A large area alone does not produce a large flow. Rain in the catchment does.

Much of the flow of the south Indian rivers, the Godavari, Krishna and Kaveri, has already been harnessed. This is yet to be done in the Brahmaputra and Ganga basins.

Groundwater

India's replenishable groundwater is about 432 cubic km. How much of it each state uses varies enormously.

If demand keeps outpacing supply, development will suffer and social disruption can follow.

Lagoons and backwaters. India's long, indented coast has formed many lagoons and lakes. Kerala, Odisha and West Bengal have large surface water resources in them. The water is generally brackish, so it is used for fishing and for irrigating certain paddy varieties and coconut, not for drinking.

Who uses the water?

India has been an agrarian economy, with about two thirds of its people dependent on farming, so irrigation has been a high priority in the Five Year Plans. Multipurpose river valley projects, such as Bhakra Nangal, Hirakud, Damodar Valley, Nagarjuna Sagar and the Indira Gandhi Canal Project, were taken up for this reason.

The industrial and domestic shares are expected to grow with development, so agriculture's share is expected to decline over time, though it will remain by far the largest.

Pause and predict: farms use 89 per cent of surface water and industry only 2 per cent. If industry's use doubled and farm use stayed the same in absolute terms, what would happen to agriculture's percentage share?

Check your answer: it would fall, because the total grows while the farm quantity stays put. This is exactly why the share of agriculture is expected to decline even though its absolute demand remains huge.

Why farming needs irrigation

Irrigation is needed for four reasons.

This is why the Green Revolution worked mainly in Punjab, Haryana and western Uttar Pradesh, where more than 85 per cent of net sown area is irrigated. See Land Resources and Agriculture.

The cost of success: groundwater overuse

Wheat and rice in these states depend on irrigation. Wells and tubewells irrigate 76.1 per cent of net irrigated area in Punjab and 51.3 per cent in Haryana. The states are using a large proportion of their groundwater potential, and the result is a falling groundwater table.

Beyond the textbook. For the exam: over withdrawal raises fluoride in Rajasthan and Maharashtra and arsenic in West Bengal and Bihar. In reality: fluoride and arsenic occur naturally in the rocks and sediments of these regions. Heavy pumping changes the water chemistry and draws them into drinking water, so the problem is natural presence made worse by human extraction. Why it matters: "who is to blame" has two parts, a natural source and human overuse.

Pradhan Mantri Krishi Sinchayee Yojana (PMKSY). Launched in 2015–16, it aims to bring some means of protective irrigation to all agricultural farms. Its aims include more physical access to water on the farm (Har khet ko pani), better on farm water use efficiency (Per drop more crop), sustainable water conservation practices, and integrated development of rainfed areas.

Emerging water problems

The per capita availability of water falls every day as population rises. Available water is also polluted by industrial, agricultural and domestic effluents, which shrinks what is usable.

Water quality means purity: water without unwanted foreign substances. Micro organisms, chemicals and industrial and other wastes degrade it. When toxic substances enter lakes, streams, rivers or oceans, they dissolve or stay suspended, and they can also seep down and pollute groundwater.

Why rivers are cleanest upstream. In the less populated hilly upper stretches, major rivers keep better quality. In the plains, water is used intensively for irrigation, drinking, domestic and industrial purposes, and drains carrying fertilisers, insecticides, domestic wastes and industrial effluent join the rivers. Pollutant concentration is highest in summer, when flow is low and there is less water to dilute the load.

These laws have not been implemented effectively. In 1997, 251 polluting industries were located along rivers and lakes, and the Water Cess Act, meant to reduce pollution, made only marginal impact. Public awareness and action can effectively reduce pollutants from farms, homes and industries.

Conserving and managing water

Because desalination of sea water is too costly for it to count as a real source, India must conserve what it has. The main tools are watershed development, rainwater harvesting, water recycling and reuse, and conjunctive use of water.

Recycle and reuse. Lower quality water, such as treated wastewater, is attractive for industries for cooling and fire fighting. In towns, water after bathing and washing utensils or vehicles can water gardens. This saves better quality water for drinking. Recycling is practised only on a limited scale now, but the scope is enormous.

Watershed management means efficient management and conservation of surface and groundwater. It prevents runoff and stores and recharges groundwater through percolation tanks, recharge wells and similar structures. In the broad sense, it includes conservation, regeneration and judicious use of every natural and human resource inside a watershed. It aims to balance natural resources against society, and its success depends largely on community participation.

Case study: Ralegan Siddhi, Maharashtra

Ralegan Siddhi, in the district of Ahmadnagar, is a small village that became an example of watershed development for the whole country. In 1975 it was caught in poverty and an illicit liquor trade. The turnaround began with community effort, not government money.

Today water is adequate and agriculture is flourishing, though use of fertilisers and pesticides is very high. The prosperity also raises the question of whether the present generation can carry on the work after its leader. The lesson is that watershed projects work when the community owns them, but there are only a few such success stories and most programmes are still at an early stage.

Rainwater harvesting

Rainwater harvesting captures and stores rainwater for use and recharges groundwater aquifers. It is a low cost, eco friendly technique that guides rain into borewells, pits and wells.

Traditional methods in rural areas use lakes, ponds and irrigation tanks. In Rajasthan, the Kund or Tanka (a covered underground tank) is built near or in the house or village to store harvested rainwater. Urban areas can especially benefit, since demand has outstripped supply in most cities and towns.

Two views. For the exam: transferring water from surplus to deficit areas through the inter linking of rivers is listed among the remedies for India's water problem, along with desalination of sea water in coastal areas and brackish water in arid and semi arid areas. Another reading: scholars debate such large transfers. Supporters point to the mismatch between flood prone and drought prone regions, while critics point to their cost, the displacement of people and the ecological effects on river systems. Why it matters: the most important issue for households and communities is the pricing of water.

National Water Policy 2012 and Jal Kranti Abhiyan

The National Water Policy 2012 offers a framework for a plan of action with a unified national perspective. Its main features:

The Jal Kranti Abhiyan (2015–16) aims at water security and, through it, livelihood and food security. Planned activities include selecting one water stressed village in each of 672 districts to create a Jal Gram, identifying model command areas of about 1,000 hectares in different parts of the country, abating pollution (water conservation and artificial recharge, reducing groundwater pollution and building arsenic free wells in selected areas), and mass awareness through media and school competitions.

Beyond the textbook. For the exam: water is a renewable (cyclic) resource, but its availability in usable form is limited. In reality: "renewable" does not mean "unlimited at a given place". Groundwater recharges slowly, so pumping faster than recharge behaves like mining a non renewable stock for the people living above it. Why it matters: it explains why a renewable resource can still run out locally, as in the groundwater stressed states.

Exam traps

60-second revision

Where this chapter connects

• Previous: Land Resources and Agriculture covers irrigation, drought and waterlogging, the farm side of the same story.
• Next: Mineral and Energy Resources moves from water to the exhaustible mineral and energy resources, and their conservation.
• Related: Drainage System names the Himalayan and Peninsular rivers whose basins appear here, and Planning and Sustainable Development in Indian Context shows the Indira Gandhi Canal and its waterlogging problem.