Water Resources
Why a renewable resource like water still becomes scarce in India, and how multi-purpose river projects and traditional rainwater harvesting are used to conserve and manage it.
Prelims frequently tests dam-river-basin matching (Bhakra-Nangal, Hirakud, Sardar Sarovar), water schemes (Jal Jeevan Mission, Atal Bhujal Yojana, PMKSY) and traditional harvesting structures (khadins, johads, kuls, tankas). For Mains GS-III it feeds water conservation, irrigation, groundwater depletion, drought and the ecological costs of large dams; the inter-state water-disputes thread (Article 262, Krishna-Godavari) also links to GS-II federalism.
Understand the chapter
The Paradox of Water Scarcity
Three-fourths of the earth is water, yet only a small fraction is usable freshwater, continually renewed through the hydrological cycle, which makes water a renewable resource. Despite this renewability, regions still face scarcity, and by 2025 nearly two billion people are predicted to live in absolute water scarcity. Scarcity is not merely a low-rainfall or drought problem; even water-rich cities suffer it because of over-exploitation, excessive use, unequal access and pollution.
- Freshwater sources: precipitation, surface run-off and groundwater, renewed by the hydrological cycle
- Scarcity is largely man-made, not just natural
- Even areas with ample water can be scarce if the water is polluted/bad quality
- Quality-induced scarcity: domestic, industrial, chemical and agro-pollution
Drivers of Over-Exploitation
A large and growing population demands more water for both domestic use and food production, so resources are over-exploited to expand dry-season irrigated agriculture, the single largest consumer of water. Private wells and tube-wells lower groundwater levels, threatening water availability and food security. Post-independence industrialisation and urbanisation worsened pressure, as industries are heavy water users that also need hydroelectric power, while urban housing societies run their own groundwater pumps, depleting fragile resources.
- Irrigated agriculture = largest consumer of water
- Tube-wells lower groundwater, endangering food security
- Industries: heavy water users plus demand for hydel power
- Remedies hinted: drought-resistant crops and dry-farming techniques
Multi-Purpose River Projects: 'Temples of Modern India'
A dam is a barrier across flowing water that creates a reservoir; traditionally for irrigation, today's dams integrate many uses and are called multi-purpose projects. Bhakra-Nangal on the Sutlej-Beas combines hydel power and irrigation, while Hirakud on the Mahanadi integrates conservation with flood control. Launched after Independence as vehicles of development, Nehru proudly called them the 'temples of modern India', continuing an ancient tradition of hydraulic structures.
- Uses: irrigation, electricity, domestic/industrial supply, flood control, recreation, inland navigation, fish breeding
- Classified by structure (timber, embankment, masonry), purpose and height
- Bhakra-Nangal - Sutlej-Beas (hydel + irrigation)
- Hirakud - Mahanadi (conservation + flood control)
Why Big Dams Came Under Scrutiny
Large dams now face strong opposition for ecological and social reasons. They disrupt natural flow, cause excessive reservoir sedimentation and rockier beds, fragment rivers and block fish migration/spawning, and submerge vegetation. Ironically, dams built to control floods have triggered floods through sedimentation and mostly failed in heavy rainfall; they deprive floodplains of fertile silt, induce earthquakes and water-borne diseases, and promote salinisation as farmers shift to water-intensive crops. They also spark inter-state disputes, such as Krishna-Godavari over Koyna diversion.
- Flood-control dams have themselves triggered floods (sedimentation)
- Loss of silt causes land degradation; commercial cropping causes salinisation
- Reservoir-induced seismicity and water-borne diseases
- Inter-state disputes, e.g. Krishna-Godavari (Koyna diversion by Maharashtra)
Rainwater Harvesting: The Viable Alternative
Given the costs of and resistance to big dams, decentralised water harvesting is seen as socio-economically and environmentally viable, drawing on India's ancient tradition tuned to local ecology. Hill regions used diversion channels (guls/kuls of the Western Himalayas), Bengal's floodplains used inundation channels, and arid Rajasthan used khadins (Jaisalmer) and johads. Rooftop harvesting filled underground tankas storing 'palar pani', the purest natural water, though this is declining in western Rajasthan due to the perennial Indira Gandhi Canal.
- Guls/kuls - diversion channels, Western Himalayas
- Khadins (Jaisalmer) and johads - arid-region storage
- Tankas - underground tanks storing rooftop 'palar pani'
- Tamil Nadu: first state to make rooftop rainwater harvesting compulsory
Government Water Missions
To improve water quality and access, the government runs targeted missions under the Ministry of Jal Shakti. Jal Jeevan Mission aims for 55 litres per capita per day of assured piped potable water to every rural household, while Atal Bhujal Yojana targets groundwater in water-stressed Gram Panchayats and seeks behavioural change from consumption to conservation. Pradhan Mantri Krishi Sinchayee Yojana extends protective irrigation with the goals 'har khet ko pani' and 'per drop more crop'.
- Jal Jeevan Mission: 55 litres per capita per day, rural tap water
- Atal Bhujal Yojana: 8220 stressed Gram Panchayats across 7 states
- PMKSY: 'har khet ko pani' and 'per drop more crop'
- Shillong relies on rooftop RWH despite nearby Cherrapunji/Mawsynram (world's highest rainfall)
Key terms
- Hydrological cycle
- Continuous renewal and recharge of water that makes water a renewable resource.
- Water scarcity
- Shortage caused mainly by over-exploitation, excessive use, unequal access and pollution, not only low rainfall.
- Multi-purpose river project
- Dam whose impounded water is integrated for irrigation, power, supply, flood control, navigation and fishing.
- Spillway / weir
- Section of a dam over or through which water flows intermittently or continuously.
- Guls / Kuls
- Diversion channels for irrigation built in the Western Himalayas.
- Khadins
- Arid-region fields converted into rain-fed storage structures to moisten soil, typical of Jaisalmer.
- Johads
- Traditional rainwater storage structures in parts of Rajasthan.
- Tankas
- Underground tanks storing rooftop-harvested drinking water in Rajasthan.
- Palar pani
- Rainwater, regarded in Rajasthan as the purest form of natural water.
- Salinisation
- Build-up of salts in soil due to over-irrigation and water-intensive cropping.
Must-know facts exam-ready
- By 2025, nearly 2 billion people are predicted to live in absolute water scarcity.
- Irrigated agriculture is the largest consumer of water.
- Bhakra-Nangal lies on the Sutlej-Beas basin (hydel power + irrigation).
- Hirakud on the Mahanadi integrates water conservation with flood control.
- Sardar Sarovar Dam is on the Narmada (Gujarat) and benefits 4 states: Maharashtra, MP, Gujarat, Rajasthan.
- Nehru called dams the 'temples of modern India'.
- Damodar is known as the 'river of sorrow' (Bhadu song theme).
- Jal Jeevan Mission goal: 55 litres per capita per day of piped potable water to every rural household.
- Atal Bhujal Yojana covers 8220 water-stressed Gram Panchayats across 7 states (Gujarat, Haryana, Karnataka, MP, Maharashtra, Rajasthan, UP).
- PMKSY slogans: 'har khet ko pani' and 'per drop more crop'.
- Tamil Nadu was the first state to make rooftop rainwater harvesting compulsory.
- Article 262 provides for adjudication of inter-state river water disputes (e.g. Krishna-Godavari over Koyna diversion).
Timeline
- 1st century BCSringaverapura near Allahabad had a sophisticated system channelling the flood water of the Ganga.
- Mauryan era (ChandraguptDams, lakes and irrigation systems were extensively built.
- 11th centuryBhopal Lake, one of the largest artificial lakes of its time, was built.
- 13th-14th centuryThe Hauz Khas tank in Delhi was built by Alauddin Khilji to supply water to Siri Fort.
Memory tricks remember it for good
Traps to avoid
- Water scarcity is NOT only about low rainfall/drought; it is largely man-made and even water-abundant cities face it.
- Technically 'dam' refers to the reservoir/impounded water, not just the barrier structure.
- Do not swap dams and rivers: Bhakra-Nangal is on Sutlej-Beas, Sardar Sarovar on Narmada, Hirakud on Mahanadi.
- Hirakud (Mahanadi, Odisha) is for flood control and conservation; do not confuse it with the Damodar, the 'river of sorrow'.
- Counter-intuitive but tested: flood-control dams have themselves triggered floods via reservoir sedimentation.
- Cherrapunji/Mawsynram get the world's highest rainfall, yet nearby Shillong faces acute shortage: high rainfall does not equal water security.
Exam focus
🧠 Prelims angles
- Match dams to river basins: Bhakra-Nangal (Sutlej-Beas), Hirakud (Mahanadi), Sardar Sarovar (Narmada).
- Schemes and slogans: Jal Jeevan Mission (55 lpcd), Atal Bhujal Yojana (groundwater, 7 states), PMKSY ('har khet ko pani', 'per drop more crop').
- Traditional structures and regions: guls/kuls (W. Himalayas), khadins (Jaisalmer), johads (Rajasthan), tankas (Bikaner/Phalodi/Barmer).
- 'Firsts' and ancient sites: Tamil Nadu's compulsory rooftop RWH; Sringaverapura's Ganga flood-water harvesting.
- Inter-state water disputes and Article 262 (Krishna-Godavari / Koyna).
- Statement-based: natural vs man-made causes of scarcity, and ecological impacts of large dams.
✍️ Mains angles GS-III
- Despite being a renewable resource, India faces acute water scarcity. Examine the causes and the way forward.Split into natural (variable precipitation) vs man-made causes (over-exploitation, unequal access, pollution); solutions = demand management, rainwater harvesting, drought-resistant crops, JJM/Atal Jal.
- Multi-purpose projects were once 'temples of modern India' but now face opposition. Critically examine.Weigh benefits (irrigation, power, flood control) against costs (sedimentation, displacement, seismicity, disputes); conclude with integrated, participatory water management.
- Reviving traditional water-harvesting systems is key to India's water security. Discuss.Use guls/kuls, khadins, johads, tankas and rooftop RWH as decentralised, ecologically-tuned, community-led models; link to Atal Jal's behavioural-change focus.
- (GS-II) Inter-state river water disputes strain Indian federalism. Discuss with examples.Anchor in Article 262 and the Krishna-Godavari/Koyna dispute; suggest tribunal reform and river-basin-level cooperative management.
Last-minute revision tick as you recall
- Water scarcity is mostly man-made: over-exploitation, excessive use, unequal access, pollution.
- By 2025, nearly 2 billion people may live in absolute water scarcity.
- Irrigated agriculture is the largest consumer of water.
- Dams = multi-purpose (FRIENDS: Flood control, Recreation, Irrigation, Electricity, Navigation, Domestic supply, fiSh breeding).
- Bhakra-Nangal to Sutlej-Beas; Hirakud to Mahanadi; Sardar Sarovar to Narmada.
- Nehru: dams = 'temples of modern India'; Damodar = 'river of sorrow'.
- Big dams: sedimentation, induced floods, displacement, seismicity, salinisation, rising opposition.
- Traditional RWH: guls/kuls, khadins, johads, tankas (palar pani); Tamil Nadu first to mandate rooftop RWH.
- Schemes: JJM (55 lpcd), Atal Bhujal Yojana (groundwater), PMKSY (har khet ko pani / per drop more crop).
Distilled from NCERT Class 10 · India and the Contemporary World II for UPSC. Always cross-check facts with the original NCERT.