Water Resources

Why This Matters

Three-fourths of the earth is covered in water, and water is a renewable resource — the sun lifts it from the oceans, clouds carry it, rain returns it to land and rivers, and the whole cycle starts again. So here is a puzzle that should bother you: if there is so much water, and it keeps coming back, why do whole regions run dry? Why do experts warn that by 2025 nearly two billion people could be living in absolute water scarcity?

You have seen the images — women in Rajasthan walking miles balancing earthen pots (matkas), a boy in flooded Kolkata scooping drinking water out of the streets, an earthquake survivor carrying water through the snow. The strange truth is that scarcity is often not about how much rain falls. Cities with plenty of water still run short. Rivers fat with monsoon flood the land and then leave it parched by April.

This chapter is about that puzzle — and what India is doing about it: building giant dams, fighting over them, and quietly going back to 2,000-year-old ways of catching the rain. Understanding it changes how you see the tap in your home: water is not endless, and how we manage it decides whether it lasts.

The Big Idea

Water is renewable through the hydrological cycle, yet scarcity is real — caused less by low rainfall and more by over-exploitation, excessive use, unequal access and pollution. To conserve and manage water, India built multi-purpose river projects (dams that do many jobs at once — irrigation, power, water supply, flood control) under integrated water resources management. But large dams brought heavy costs — displacement, ecological damage and protest — pushing many back toward an older, gentler solution: rainwater harvesting, both traditional and modern.

Hold two ideas side by side as you read. One is scale: a single dam can transform four states at once — and uproot thousands of people at once. The other is smallness: a tank under one family’s courtyard, or a bamboo pipe on a hillside, can quietly solve the same problem with none of the damage. The chapter is really an argument between the big and the small.

Let’s Break It Down

How water becomes a renewable resource

Freshwater is the small usable slice of all that water — fed by precipitation, surface run-off and groundwater, all of it constantly renewed and recharged through the hydrological cycle. Because water keeps moving through this cycle — evaporating, forming clouds, falling as rain, flowing and soaking in — it is replenished again and again. That endless circulation is exactly why water counts as a renewable resource.

Water scarcity — and why it is not just about rainfall

It is tempting to picture scarcity only as a desert with no rain. But the availability of water varies over space and time mainly due to seasonal and annual variations in rainfall, while scarcity in most cases is caused by over-exploitation, excessive use and unequal access among different social groups. The main drivers:

• Large and growing population — more people need more water, not just to drink but to grow more food.
• Irrigated agriculture, the largest consumer of water — to raise food-grain output, water resources are over-exploited to expand irrigation for dry-season farming. Farmers’ own wells and tube-wells pump so hard that groundwater levels fall, hurting future water availability and food security.
• Industrialisation and urbanisation — industries are heavy users of water and need power (much of it hydroelectric). Crowded cities and housing colonies sink their own groundwater pumps, draining fragile resources.
• Bad-quality (polluted) water — even where there is enough water, it may be unfit to use, polluted by domestic and industrial waste, chemicals, pesticides and fertilisers. So an area can have ample water and still suffer scarcity.

This is why a city can be water-rich on paper yet still go thirsty. Government responses include Atal Bhujal Yojana (Atal Jal) to improve groundwater management in water-stressed Gram Panchayats across seven states, and the Jal Jeevan Mission (JJM), whose goal is assured piped potable water — about 55 litres per person per day — to every rural household.

Multi-purpose river projects: dams as “temples of modern India”

So how do we conserve and manage water? One ancient answer is the dam — a barrier across flowing water that obstructs, directs or slows the flow, usually creating a reservoir (a stored lake of water) behind it. (Interestingly, the word “dam” often refers to the reservoir, not just the wall. Most dams have a spillway through which water is let out.)

India has built dams in most of its river basins since ancient times — from the flood-water harvesting at Sringaverapura near Allahabad in the 1st century B.C., to the dams of Chandragupta Maurya, to Bhopal Lake (11th century) and the Hauz Khas tank in Delhi (built by Allauddin Khilji). After Independence these became multi-purpose projects: dams built not only to impound water for irrigation but for electricity generation, water supply for homes and industry, flood control, recreation, inland navigation and fish breeding — all integrated together. Jawaharlal Nehru proudly called them the “temples of modern India”, because they would tie farming and village life to industry and city growth.

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Famous examples to remember:

• Bhakra-Nangal project (Sutlej-Beas basin) — water used for both hydel power and irrigation.
• Hirakud project (Mahanadi basin) — integrates conservation of water with flood control.
• Sardar Sarovar Dam on the Narmada in Gujarat — one of India’s largest projects, spanning four states (Maharashtra, Madhya Pradesh, Gujarat, Rajasthan), meant to bring assured water to drought-prone and desert areas.

Why large dams came under fire

In recent years multi-purpose projects and large dams have come under great scrutiny and opposition. The problems are serious:

• Damaged river ecology — regulating and damming a river spoils its natural flow, causing poor sediment flow and excessive sedimentation at the bottom of the reservoir. This leaves rockier stream beds and poorer habitats for aquatic life, and fragments rivers, making it hard for fish to migrate to spawn.
• Submerged land and decomposing vegetation — reservoirs built on floodplains drown existing vegetation and soil, which then decomposes.
• Displacement and loss of livelihood — large numbers of people, often poor villagers and tribal communities, are forced off their land. The Narmada Bachao Andolan is the best-known movement opposing the building of large dams over the Narmada, on the grounds of such displacement and ecological harm.
• Floods, ironically — dams built to control floods have sometimes triggered them through reservoir sedimentation, and have largely failed to control floods during very heavy rainfall. The devastating floods cause soil erosion, and trapped silt is denied to the floodplains, where it was a natural fertiliser — worsening land degradation.
• Other harms — multi-purpose projects have induced earthquakes, caused water-borne diseases and pests, and led to pollution. Easy irrigation has pushed farmers toward water-intensive commercial crops, with consequences like salinisation of the soil. Sharing dammed water also sparks inter-state disputes, such as the Krishna-Godavari dispute between Maharashtra, Karnataka and Andhra Pradesh over diversion of water at Koyna.

Rainwater harvesting: going back to catch the rain

Given the drawbacks of and rising resistance to large dams, many saw rainwater harvesting as a viable alternative — socially, economically and environmentally. Ancient India had an extraordinary tradition of it, with techniques matched to local soil and rainfall:

• Guls and kuls — diversion channels in the Western Himalayas that carry stream water to fields.
• Rooftop rainwater harvesting — collecting rain off roofs to store drinking water, especially in Rajasthan.
• Inundation channels — in the floodplains of Bengal, to irrigate fields.
• Khadins (Jaisalmer) and Johads (other parts of Rajasthan) — fields turned into rain-fed storage so water stands and moistens the soil in arid regions.

Tankas of Rajasthan. In semi-arid and arid Rajasthan — Bikaner, Phalodi, Barmer — almost every house traditionally had an underground tank, or tanka, for storing drinking water, built inside the house or courtyard. (One household in Phalodi had a tank 6.1 m deep, 4.27 m long, 2.44 m wide — as big as a room.) The tanka was connected by a pipe to the sloping rooftop; rain ran down the pipe into the tank. The first spell of rain was not collected — it washed the roof and pipes clean — and only later showers were stored. This rainwater, called palar pani, was considered the purest natural water and stayed reliable through the dry summers when other sources failed; some families even built cool underground rooms beside the tanka. Sadly, the practice is now declining in western Rajasthan because the perennial Indira Gandhi Canal brings plenty of water, though some still keep their tankas — they dislike the taste of tap water.

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Modern adaptations. Rooftop rainwater harvesting is now being revived across rural and urban India:

• Shillong, Meghalaya — nearly every household harvests rooftop rainwater, meeting 15-25% of its water needs — striking, since nearby Cherrapunji and Mawsynram get the world’s highest rainfall yet Shillong faces acute shortage.
• Gendathur, near Mysuru, Karnataka — a remote village where ~200 households installed rooftop systems and earned the rare distinction of being “rich in rainwater.” With ~1,000 mm annual rain, 80% collection efficiency and about 10 fillings, each house can collect roughly 50,000 litres a year.
• Tamil Nadu — the first Indian state to make rooftop rainwater harvesting compulsory for all houses, with legal penalties for defaulters.

In a modern setup, rooftop rain is collected through a PVC pipe, filtered using sand and bricks, carried by an underground pipe to a sump for immediate use, and the excess is sent to a well to recharge the groundwater for later.

Bamboo drip irrigation of Meghalaya. In Meghalaya, a 200-year-old system taps stream and spring water using bamboo pipes. Water from perennial hilltop springs is diverted downhill by gravity through bamboo channels, split into branches, and routed over hundreds of metres. About 18-20 litres enters the system and is finally delivered as just 20-80 drops per minute right at the roots of the plant — an ingenious, low-tech drip irrigation.

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Summary

• Water is renewable through the hydrological cycle (precipitation, surface run-off, groundwater), yet scarcity is real — caused mainly by over-exploitation, excessive use, unequal access and pollution, not just by low rainfall.
• Drivers of scarcity: growing population, water-hungry irrigated agriculture, industrialisation and urbanisation (falling groundwater), and polluted water — so even a water-rich region can be short of usable water.
• Multi-purpose river projects are dams that do many jobs at once — irrigation, hydroelectricity, water supply, flood control, navigation, recreation, fish breeding — under integrated water resources management. Nehru called them the “temples of modern India.” Examples: Bhakra-Nangal, Hirakud, Sardar Sarovar (Narmada).
• Large dams carry heavy costs: displacement and lost livelihoods (the Narmada Bachao Andolan), disturbed river ecology and sedimentation, submerged land, soil salinisation, induced earthquakes, inter-state disputes — and they have sometimes triggered floods instead of controlling them.
• Rainwater harvesting is the gentler alternative — traditional methods like guls/kuls, khadins, johads and the tankas of Rajasthan (storing pure palar pani), and modern revivals (Gendathur, Shillong, Tamil Nadu’s compulsory rule) plus Meghalaya’s bamboo drip irrigation.

What’s Next

You have seen how India manages the water that makes farming possible. Next comes the thing that water is largely used for: Agriculture. The next chapter looks at the crops India grows, the types of farming, the cropping seasons (rabi, kharif, zaid), and the challenges Indian farmers face — turning the water of this chapter into the food on the country’s plate.