Water Resources

1. Why water resources matter

Water gives life — we need it to drink, cook, wash, grow food and run factories — but it can also take life, as in floods. About three-fourths of the earth’s surface is covered with water, yet only a small proportion is freshwater that can actually be used. This freshwater comes mainly from surface run-off and groundwater, both continually renewed and recharged through the hydrological cycle (the water cycle).

Because the cycle keeps replenishing it, water is a renewable resource. Through the ages humans have chosen to live near water sources — rivers, springs, lakes, ponds and oases. Today industries also depend on water for processing and for cooling machines, and on hydel (hydro-electric) power generated from water.

2. Water scarcity — what it really is

Given how abundant and renewable water seems, it is surprising that the world suffers water scarcity. It is predicted that by 2025 nearly two billion people will live in absolute water scarcity. The usual image is dry, drought-prone areas like the deserts of Rajasthan, where women balance matkas (earthen pots) and walk long distances for water.

The main drivers of scarcity:

• Large and growing population — needs more water for domestic use and for producing more food grains.
• Over-exploitation for irrigation — to expand dry-season agriculture, water is over-used. Farmers sink their own wells and tube-wells, causing falling groundwater levels and threatening food security.
• Industrialisation & urbanisation — industries are heavy users of water and of hydroelectric power; growing, dense cities with their own groundwater pumping further deplete fragile resources.
• Pollution — even where water is abundant, it may be unusable because it is polluted by domestic and industrial wastes, chemicals, pesticides and fertilisers, making it hazardous.

Jal Jeevan Mission (JJM): a Government of India scheme to provide every rural household assured piped potable water at 55 litres per capita per day. Atal Bhujal Yojana (Atal Jal): aims to manage groundwater and bring behavioural change in over-exploited blocks across seven states (Gujarat, Haryana, Karnataka, Madhya Pradesh, Maharashtra, Rajasthan, Uttar Pradesh) covering about 37% of India’s stressed blocks.

3. Need for conservation and management

Over-exploitation and mismanagement impoverish this resource and cause an ecological crisis. Conserving and managing water is the need of the hour to:

• safeguard ourselves from health hazards,
• ensure food security,
• continue our livelihoods and productive activities, and
• prevent degradation of natural ecosystems.

Even those with access to water need to use it wisely, because poor management today damages the resource for everyone tomorrow.

4. Multi-purpose river projects & what a dam is

From ancient times Indians built sophisticated hydraulic structures — dams of stone rubble, reservoirs, lakes, embankments and canals (e.g. Sringaverapura near Allahabad in the 1st century B.C., works during Chandragupta Maurya, Bhopal Lake in the 11th century, the Hauz Khas tank built for the Siri Fort area). This tradition continued into modern India by building dams in most river basins.

Dams were traditionally built to impound rivers and rainwater for irrigation. Today they serve many uses at once — so they are called multi-purpose projects, “multi-purpose” because the stored water is used for irrigation, electricity generation (hydel power), domestic and industrial water supply, flood control, recreation, inland navigation and fish breeding.

Launched after Independence with an integrated water resources management approach, these projects were seen as the vehicle to lead the nation to development, overcoming its colonial past. Jawaharlal Nehru proudly called dams the “temples of modern India”, because they would integrate agriculture and the village economy with rapid industrialisation and urban growth.

5. Benefits of multi-purpose projects

These are the arguments in favour of dams:

• Irrigation — canals carry water to fields, expanding cultivated area and boosting food-grain production.
• Hydroelectricity — clean power for industries and homes.
• Domestic & industrial water supply — especially to drought-prone areas.
• Flood control — regulating river flow checks floods (the original aim).
• Other uses — recreation, inland navigation and fish breeding.
• Drought-proofing — assured supply to deserts, e.g. Sardar Sarovar to Rajasthan and Gujarat.

6. Criticism of multi-purpose projects

In recent years dams have come under great scrutiny and opposition:

• Disturb natural flow & sediment: regulating and damming rivers causes poor sediment flow and excessive sedimentation at the reservoir bottom — leading to rockier stream beds and poorer habitats for aquatic life.
• Harm aquatic life: dams fragment rivers, making it hard for aquatic fauna to migrate, especially for spawning (breeding).
• Submergence & displacement: reservoirs on floodplains submerge land and vegetation (which decomposes over time) and displace local people from land and livelihood.
• Failed flood control: ironically, dams built to control floods have triggered floods due to sedimentation; big dams are mostly unsuccessful in controlling floods during heavy rain. These floods cause severe soil erosion and rob floodplains of fertile silt.
• Induced problems: projects have induced earthquakes, caused water-borne diseases and pests, and pollution from excessive water use.
• Cropping & soil change: irrigation shifts farmers to water-intensive commercial crops, causing salinisation of the soil.
• Inter-state disputes: sharing of costs and benefits sparks conflicts (e.g. the Krishna-Godavari dispute involving Karnataka, Andhra Pradesh and Maharashtra over diversion at Koyna).

Pradhan Mantri Krishi Sinchayee Yojana tries to expand assured irrigation (har khet ko pani) and improve on-farm water-use efficiency (per drop more crop).

7. Sardar Sarovar Dam & the Narmada Bachao Andolan

The Sardar Sarovar Dam on the Narmada River in Gujarat is one of India’s largest water-resource projects, covering four states — Maharashtra, Madhya Pradesh, Gujarat and Rajasthan. It is meant to provide water to drought-prone and desert areas: irrigation to about 18.45 lakh hectare in Gujarat (covering 3112 villages in 15 districts), plus desert districts of Barmer and Jalore in Rajasthan and the hilly tract of Maharashtra. About 75% of Gujarat’s command area is drought-prone, so assured supply will make it drought-proof.

8. Rainwater harvesting — the alternative

Given the disadvantages of and resistance to big projects, water harvesting emerged as a viable alternative — sound both socio-economically and environmentally. In ancient India, alongside grand hydraulic structures, an extraordinary tradition of water-harvesting developed. People had deep knowledge of rainfall regimes and soil types and built techniques suited to local conditions.

9. Traditional rainwater harvesting methods

• Guls / kuls: diversion channels in the hill and mountainous regions of the Western Himalayas for agriculture.
• Rooftop harvesting: commonly used to store drinking water, particularly in Rajasthan.
• Inundation channels: in the flood plains of Bengal, to irrigate fields.
• Khadins & Johads: in arid and semi-arid regions, fields were turned into rain-fed storage structures that let water stand and moisten the soil — khadins in Jaisalmer and johads elsewhere in Rajasthan.
• Tankas: in semi-arid Rajasthan (Bikaner, Phalodi, Barmer), almost every house had underground tanks (tankas) for storing drinking water, as large as a big room (one in Phalodi was 6.1 m deep, 4.27 m long, 2.44 m wide). Built inside the house/courtyard, connected to sloping roofs by pipes; the first spell of rain was let go to clean the roof, and later rainwater was collected.

Sadly, in western Rajasthan rooftop harvesting is declining as the perennial Indira Gandhi Canal now supplies tap water, though some still keep tankas, disliking the taste of tap water.

10. Modern (rooftop) rainwater harvesting

Today rooftop rainwater harvesting is being adapted successfully in many rural and urban parts of India.

• Gendathur (Mysuru, Karnataka): about 200 households installed rooftop systems. With 1,000 mm annual rainfall, 80% collection efficiency and ~10 fillings, each house collects ~50,000 litres a year — 1,00,000 litres from 200 houses; the village is “rich in rainwater”.
• Shillong (Meghalaya): rooftop harvesting is most common — though nearby Cherapunjee/Mawsynram get the world’s highest rainfall, Shillong faces shortage, so nearly every house harvests, meeting 15–25% of household water needs.
• Tamil Nadu: the first state to make rooftop rainwater harvesting compulsory for all houses, with legal provisions to punish defaulters.

11. NCERT Exercise — Q1 Multiple choice (solved)

(i) Classify each as ‘suffering / not suffering from water scarcity’:

• (a) Region with high annual rainfall → not suffering.
• (b) Region with high rainfall but large population → suffering (high demand).
• (c) Region with high rainfall but highly polluted water → suffering (bad quality).
• (d) Region with low rainfall and low population → not suffering (low demand).

(ii) Which is not an argument in favour of multi-purpose projects?

• Answer: (c) “Multi-purpose projects lead to large scale displacements and loss of livelihood” — that is a criticism, not a benefit.

(iii) Identify the mistakes and rewrite correctly:

• (a) Wrong: “Multiplying urban centres… have helped in proper utilisation of water resources.” → Correct: they have over-exploited and depleted water resources.
• (b) Wrong: “Regulating and damming of rivers does not affect natural flow and sediment flow.” → Correct: it does affect natural flow and causes excessive sedimentation.
• (c) Wrong: “In Rajasthan rooftop harvesting has gained popularity despite the Indira Gandhi Canal.” → Correct: it has declined because tap water is now available from the Indira Gandhi Canal.

12. NCERT Exercise — Q2 (about 30 words each)

(i) How does water become a renewable resource? Freshwater is obtained from precipitation, surface run-off and groundwater, all continually renewed and recharged through the hydrological cycle — so water keeps replenishing and is renewable.

(ii) What is water scarcity and its main causes? Water scarcity is the shortage of usable water relative to demand. Main causes: large/growing population, over-exploitation for irrigation and industry, unequal access, and pollution of available water.

(iii) Compare advantages and disadvantages of multi-purpose projects. Advantages: irrigation, hydel power, water supply, flood control, navigation, fish breeding, drought-proofing. Disadvantages: displacement, submergence, sedimentation, harm to aquatic life, induced earthquakes, soil salinisation and inter-state disputes.

13. NCERT Exercise — Q3 (about 120 words each)

(i) Rainwater harvesting in semi-arid Rajasthan. In semi-arid and arid Rajasthan (Bikaner, Phalodi, Barmer), almost every house traditionally had an underground tanka for storing drinking water. Tankas were built inside the main house or courtyard, some as large as a big room (one in Phalodi was 6.1 m deep, 4.27 m long and 2.44 m wide). They were connected to the sloping rooftops by pipes; rain falling on the roof flowed down and was stored. The first spell of rain was let go to wash the roof and pipes clean, and water from later showers was collected. This stored rainwater, called palar pani, is the purest natural water and lasts till the next rains. Some houses built cool underground rooms beside the tanka. Today the practice is declining due to the Indira Gandhi Canal.

(ii) Modern adaptations of traditional rainwater harvesting. In many parts of rural and urban India, traditional methods are being modernised through rooftop rainwater harvesting. Rooftop rainwater is collected through a PVC pipe, filtered using sand and bricks, and taken by underground pipe to a sump for immediate use; excess is led to a well that recharges groundwater, which can be drawn later. In Gendathur (Mysuru, Karnataka), about 200 households installed such systems and harvest about 1,00,000 litres a year, making the village rich in rainwater. In Shillong, nearly every house harvests rooftop water, meeting 15–25% of needs. Tamil Nadu has made rooftop harvesting compulsory for all houses, with penalties for defaulters — showing how tradition is adapted for modern water security.

14. Common confusions

• Scarcity vs low rainfall: scarcity is mostly from over-use, unequal access and pollution — not only low rainfall. Water-rich areas can be scarce too.
• Dam vs reservoir: “dam” technically refers to the reservoir, not just the wall.
• Single-purpose vs multi-purpose: a multi-purpose project serves many uses at once (irrigation + power + flood control + …).
• Khadin / johad vs tanka: khadins and johads store water in/on fields; tankas are underground tanks for drinking water.
• Guls/kuls vs bamboo drip: guls/kuls are Himalayan diversion channels; bamboo drip is Meghalaya’s spring-tapping drip system.
• NBA target: the Narmada Bachao Andolan opposed the Sardar Sarovar Dam over displacement and submergence — not all dams in general.

15. Quick revision checklist

• Water is renewable via the hydrological cycle; usable freshwater is scarce.
• Scarcity = population + over-exploitation + unequal access + pollution.
• Multi-purpose project uses: irrigation, hydel power, water supply, flood control, navigation, fish breeding.
• Nehru: dams = “temples of modern India”. Bhakra-Nangal (Satluj-Beas), Hirakud (Mahanadi).
• Criticism: displacement, submergence, sedimentation, aquatic harm, induced quakes, salinisation, disputes.
• Sardar Sarovar (Narmada) → opposed by Narmada Bachao Andolan.
• Traditional harvesting: guls/kuls, khadins, johads, tankas (palar pani), bamboo drip.
• Modern: rooftop (PVC pipe → filter → sump → well → recharge). Tamil Nadu made it compulsory.