Chapter 3: Water Resources
1. Introduction to Water Resources
• 71% of the Earth’s surface is covered with water.
• Only 2.5% of the total water is freshwater, suitable for human use.
• Freshwater is available in:
o Glaciers & Ice caps – ~70% of freshwater
o Groundwater – ~30%
o Surface water (rivers, lakes, ponds) – very small proportion
• Water is a renewable resource due to the hydrological cycle.
3. Water Scarcity
Definition: A situation where water availability is insufficient to meet the demands.
Causes of Water Scarcity:
1. Overexploitation of water for agriculture and industry.
2. Population growth: Increases domestic, industrial, and agricultural demand.
3. Unequal access to water (rural vs urban areas).
4. Pollution of water bodies. Ex- MNCs multinational corporation
5. Urbanization and industrialization reduce groundwater recharge.
6. Climate change and changing rainfall patterns.
4. Need for Water Conservation
1. To meet increasing demand.
2. To ensure equitable distribution.
3. To maintain ecological balance.
4. To reduce over-dependence on groundwater.
5. To ensure water for future generations.
6. To prevent water-related conflicts.
Real-Life Example:Kolkata: After 180 mm of rainfall, still a shortage of drinking water due to
urban flooding and pollution.
3. Government Schemes for Water Management
Atal Bhujal Yojana (Atal Jal)
Launched by the Ministry of Jal Shakti.
Implemented in 8220 water-stressed Gram Panchayats of 229 administrative block in 80 Districts
across 7 states.
Aims to improve groundwater management through community participation.
Focuses on behavioral change: from consumption to conservation.
Jal Jeevan Mission (JJM)Goal: To provide 55 litres per capita per day of potable piped water to
every rural household.
Ensures long-term functionality of tap water connections.
Emphasizes ease of living and quality of life improvement.
5. Multipurpose River Valley Projects
Introduction
• India is a land of rivers and monsoons.
• Water is essential for agriculture, industry, domestic use, hydropower, and maintaining
ecosystems.
• Since ancient times, Indians developed hydraulic structures (dams, lakes, canals) to
conserve water.
• Modern India continues this tradition with multi-purpose river valley projects.
Hydraulic Structures in Ancient India
Evidence from archaeology and history shows:
• 1st century B.C. – Sringaverapura (near Allahabad): floodwater harvesting system on River
Ganga.
• Mauryan Period (Chandragupta Maurya) – large dams, lakes, irrigation canals.
• Kalinga (Odisha), Nagarjunakonda (Andhra Pradesh), Bennur (Karnataka), Kolhapur
(Maharashtra): irrigation works.
• 11th century – Bhopal Lake (largest artificial lake of its time).
• 14th century – Hauz Khas Tank, Delhi, built by Iltutmish to supply water to Siri Fort.
Shows continuity of water conservation practices from ancient to modern times.
What is a Dam?
• A dam is a barrier across flowing water that obstructs, directs, or retards its flow, creating a
reservoir/lake.
• Key Features:
o Spillway / Weir → controlled release of water.
o Classifications:
▪ By material/structure → timber, embankment, masonry.
▪ By height → low, medium, high dams.
• Traditional use: irrigation.
• Modern use: multi-purpose projects.
Multi-Purpose River Valley Projects
Definition: Projects where water from dams is used for multiple purposes in an integrated
manner.
Objectives & Uses:
1. Irrigation – major support for agriculture.
2. Hydroelectric Power (HEP) – clean energy.
3. Water Supply – for domestic & industrial use.
4. Flood Control – regulates river flow.
5. Recreation – boating, tourism.
6. Inland Navigation – transport.
7. Fish Breeding – livelihood support.
Examples:
• Bhakra Nangal Project (Satluj-Beas Basin): irrigation + hydel power.
• Hirakud Dam (Mahanadi Basin): water conservation + flood control.
• Sardar Sarovar Dam (Narmada River, Gujarat): irrigation + drinking water + drought
proofing.
Nehru’s Vision
• After independence, Jawaharlal Nehru called dams the “Temples of Modern India”.
• Aim: integrate agriculture + village economy + industrialisation + urban growth.
• Symbol of progress and self-reliance.
Benefits of Multi-Purpose Projects
Irrigation expansion → agriculture growth.
Hydropower → reduces dependence on fossil fuels.
Flood control → protects life & property.
Employment generation → rural prosperity.
Drought-proofing in arid regions.
Problems and Criticisms
In recent years, dams have faced opposition due to negative impacts:
Environmental Issues
• Disturbs natural flow → affects aquatic life.
• Sedimentation in reservoirs → reduces fertility of floodplains.
• Submergence of forests, soil, biodiversity.
• Water-logging, salinisation of soil.
Social Issues
• Displacement of tribal & rural people.
• Loss of livelihood and cultural heritage.
Economic Issues
• Very high cost → burden on economy.
• Less effective in flood control (sometimes cause floods).
• Induced earthquakes, water-borne diseases.
Case Study: Sardar Sarovar Dam (Narmada River, Gujarat)
• Covers 4 states → Gujarat, Maharashtra, Rajasthan, Madhya Pradesh.
• Irrigation:
o 18.45 lakh ha in Gujarat (3112 villages, 15 districts).
o 2.46 lakh ha in Rajasthan (Barmer & Jalore desert).
o 37,500 ha in Maharashtra (tribal areas).
• 75% of Gujarat command area → drought-prone.
• Aim: make drought areas drought-proof.
Government Efforts – Pradhan Mantri Krishi Sinchayee Yojana (PMKSY)
• Goal: “Har Khet Ko Pani” (irrigation for every farm).
• Objectives:
o Expand cultivable area under irrigation.
o Improve water-use efficiency (“Per Drop More Crop”).
o Encourage micro-irrigation (drip/sprinklers).
o Promote sustainable water conservation.
Inter-State River Water Disputes
• Krishna–Godavari Dispute → Maharashtra diverting more water at Koyna for multi-
purpose project.
• Karnataka & Andhra Pradesh → protested as it reduces downstream flow affecting
agriculture & industries.
Highlights political challenges of water sharing.
Conclusion
• Multi-purpose projects are crucial for water management & development.
• But need to balance benefits vs ecological & social costs.
• Focus on sustainable water conservation methods → rainwater harvesting, watershed
management, micro-irrigation.
Possible Exam Questions
Very Short Answer (1 mark)
1. Who described dams as “temples of modern India”?
2. Name the river on which Hirakud Dam is built.
3. What is the main objective of PMKSY?
Short Answer (3 marks)
1. Mention any three advantages of multi-purpose river valley projects.
2. Why are multi-purpose projects facing opposition? Give reasons.
3. State any three ancient water conservation structures of India.
Long Answer (5 marks)
1. Explain how multi-purpose river valley projects help in water conservation and
management.
2. “Multi-purpose river valley projects have both advantages and disadvantages.” Explain.
3. Write a note on the Sardar Sarovar Dam and its benefits.
Map-Based (3 marks)
Locate and label:
• Bhakra Nangal Dam (Satluj)
• Hirakud Dam (Mahanadi)
• Nagarjuna Sagar Dam (Krishna)
• Sardar Sarovar Dam (Narmada)
Project Name River States
Bhakra Nangal Satluj Himachal, Punjab
Hirakud Mahanadi Odisha
Sardar Sarovar Narmada Gujarat, MP, Maharashtra
Tehri Dam Bhagirathi Uttarakhand
8. Rainwater Harvesting (RWH)
Introduction
• Multipurpose river valley projects face criticism due to ecological damage, displacement,
cost, and failure to control floods.
• As an eco-friendly alternative, traditional and modern rainwater harvesting systems and
indigenous irrigation techniques are gaining importance.
• These methods are socio-economically viable, environmentally sustainable, and locally
adaptable.
Rainwater Harvesting in Ancient & Medieval India
• Ancient Indians had deep knowledge of rainfall patterns & soil types.
• Developed diverse systems for rainwater, groundwater, river water, and floodwater
harvesting.
Regional Techniques:
• Hills & Mountains (Western Himalayas):
o Diversion channels called ‘guls’ or ‘kuls’ → carried water to fields.
• Rajasthan (Arid & Semi-arid Regions):
o ‘Khadins’ (Jaisalmer): fields converted into storage tanks → rainwater moistened
soil.
o ‘Johads’: small earthen check dams to collect rainwater.
o Tankas (Bikaner, Phalodi, Barmer):
▪ Underground tanks for drinking water.
▪ Built in courtyards/inside houses, connected to sloping roofs by pipes.
▪ First rain not collected (roof cleaning), later rains stored.
▪ Could hold water till next rainfall → reliable in summer.
▪ Rooms next to tankas stayed cool in summer.
▪ Rainwater (locally called Palar Pani) considered purest water.
▪ Even neighbor’s rooftops were sometimes used by diverting water through
pipes
• Bengal (Flood Plains):
o Inundation channels to irrigate fields with floodwater.
Rooftop Rainwater Harvesting (Modern Examples)
(a) Rajasthan
• Still used in houses, though declining due to Indira Gandhi Canal water supply.
• Some families prefer harvested water due to better taste compared to tap water.
(b) Gendathur Village, Mysuru (Karnataka)
• Every household has rooftop harvesting.
• Annual rainfall: 1,000 mm.
• With 80% efficiency & 10 fillings, each house → 50,000 litres annually.
• Nearly 200 households harvest → 1,00,000 litres annually.
• Result: village became rainwater-rich.
(c) Shillong (Meghalaya)
• Despite heavy rainfall in Cherrapunjee & Mawsynram (world’s highest rainfall), Shillong faces
water scarcity.
• Solution: rooftop harvesting → meets 15–25% household needs.
(d) Tamil Nadu
• First state in India to make rooftop rainwater harvesting compulsory by law.
• Defaulters can be punished → model for other states.
Advantages of Rainwater Harvesting
Reduces dependence on rivers, dams, groundwater.
Simple, low-cost, and sustainable.
Provides pure drinking water.
Helps in drought-prone areas.
Recharges groundwater levels.
Reduces flooding & soil erosion.
Bamboo Drip Irrigation System (Meghalaya)
• 200-year-old indigenous technique.
• Uses bamboo pipes to divert water from springs/streams to fields.
Features:
1. Gravity-based: water from hilltops flows down naturally.
2. Control of Flow:
o 18–20 litres per minute enters system.
o Reduced to 20–80 drops per minute at roots.
o Prevents wastage.
3. Distribution:
o Bamboo pipes cut & laid to direct water to plant sites.
o Can cross roads/fields by raising pipes.
4. Eco-friendly:
o No wastage of water.
o Entirely made of bamboo → biodegradable, low-cost.
Comparison: Modern Dams vs. Traditional Harvesting
Aspect Dams & Multi-purpose Projects Rainwater Harvesting / Bamboo Drip
Scale Large, covers many states Local, community-based
Cost Very high Low, affordable
Impact Displacement, ecological damage Eco-friendly, sustainable
Reliability High but dependent on politics & maintenance Reliable for local needs
Conclusion
• India must balance between large-scale projects & traditional sustainable methods.
• Rainwater harvesting and indigenous irrigation (like bamboo drip) are best suited for local
needs, especially in arid, semi-arid, and hilly regions.
• They reduce overdependence on big dams and ensure water security for future generations.
Possible Exam Questions
Very Short (1 mark)
1. Which state made rooftop rainwater harvesting compulsory?
2. What is ‘Palar Pani’?
3. Name any two traditional rainwater harvesting methods in Rajasthan.
Short (3 marks)
1. Explain the ‘tanka’ system in Rajasthan.
2. Why is rooftop harvesting important in Shillong?
3. Mention any three advantages of rainwater harvesting.
Long (5 marks)
1. “Rainwater harvesting is a viable alternative to multipurpose projects.” Justify.
2. Describe the bamboo drip irrigation system in Meghalaya.
3. Explain with examples traditional water harvesting practices in different regions of India.
Map-based Question
Locate & label:
• Rajasthan (Johads/Khadins, Tankas)
• Meghalaya (Bamboo Drip Irrigation, Shillong)
• Gendathur (Karnataka)
• Tamil Nadu (compulsory rooftop harvesting)
9. Traditional Water Harvesting Systems in India
Region Method Description
Rajasthan Johads, Khadins Small earthen check dams to store rainwater
Himachal Pradesh Kuls Channels from glaciers
Ladakh Zings Small tanks to store glacier melt
Kerala Surangams Cave-like tunnels to tap underground water
Maharashtra Bandharas Small check dams to raise groundwater level
Sustainable, eco-friendly, and community-managed systems
11. Important Previous Year Questions (PYQs)
1. What is rainwater harvesting? Mention two methods. (3M)
2. State two causes of water scarcity in India. (2M)
3. Name two multipurpose river valley projects. Mention one use of each. (3M)
4. Why are multipurpose projects criticised? (3M)
5. Mention any two traditional water harvesting methods practiced in India. (2M)
. Very Short Answer Type Questions (1 Mark)
1. What is water scarcity?
2. Name any two multipurpose river valley projects of India.
3. What is rainwater harvesting?
4. Mention two objectives of multipurpose river valley projects.
5. Name two states which practice bamboo drip irrigation.
6. Which state practices rooftop rainwater harvesting as a mandatory law?
7. What is the main cause of water scarcity in India? (PYQ – 2019)
8. Define the hydrological cycle. (PYQ – 2012)
9. What is the percentage of freshwater available on the earth’s surface?
10. Which multipurpose project is built on the Satluj River?
2. Short Answer Type Questions (3 Marks)
1. Why is water scarcity becoming a serious problem in India? Explain any three reasons. (PYQ –
2016, 2020)
2. Explain any three multipurpose uses of dams. (PYQ – 2014)
3. Explain any three problems faced due to multipurpose river valley projects. (PYQ – 2017)
4. Write a short note on rainwater harvesting in Rajasthan. (PYQ – 2013)
5. Explain any three traditional methods of rainwater harvesting used in India. (PYQ – 2015)
6. How does urbanization and industrialization lead to water scarcity? (PYQ – 2018)
7. State three objectives of rainwater harvesting.
8. Mention three advantages of multipurpose river valley projects.
9. Explain the role of dams in flood control and irrigation.
10. Why is rooftop rainwater harvesting the most common practice in Shillong? (PYQ – 2019)
3. Long Answer Type Questions (5 Marks)
1. Explain any five causes of water scarcity in India. (PYQ – 2012, 2016, 2019, 2022)
2. Explain the advantages and disadvantages of multipurpose river valley projects. (PYQ – 2014,
2017)
3. How has irrigation changed the cropping pattern in India?
4. Why are multipurpose projects considered the "temples of modern India"? Do you agree?
Give reasons. (PYQ – 2018)
5. “Multipurpose projects and large dams have been the cause of many new social
movements.” Support the statement with examples. (PYQ – 2015, 2020)
6. Explain the need for water conservation and management in India. (PYQ – 2013, 2016)
7. What is rainwater harvesting? Explain its significance in solving the water problem in India.
(PYQ – 2015, 2019)
8. “Water scarcity is both a natural and human-made problem.” Justify the statement with five
suitable arguments. (PYQ – 2020, 2021)
9. Explain with examples how people in different regions of India conserved water in traditional
ways. (PYQ – 2012, 2014, 2019)
10. Why has rooftop rainwater harvesting been made compulsory in most states of India? Give
reasons. (PYQ – 2018)
4. Map-Based Questions
1. Bhakra Nangal Dam – Satluj River (PYQ)
2. Hirakud Dam – Mahanadi River (PYQ)
3. Nagarjuna Sagar Dam – Krishna River (PYQ)
4. Sardar Sarovar Dam – Narmada River (PYQ)
5. Tehri Dam – Ganga River (PYQ)
6. Salal Project – Chenab River (PYQ)
7. Rana Pratap Sagar – Chambal River
8. Indira Gandhi Canal – Rajasthan
9. Koyna Project – Maharashtra
10. Tungabhadra Dam – Karnataka
5. Value-Based Questions
1. “Large multipurpose projects lead to conflicts between regions and states.” Justify with
examples.
2. Suggest measures to improve the efficiency of irrigation in India.
3. What is bamboo drip irrigation? How is it eco-friendly?
4. Compare traditional water harvesting with modern water management systems.
5. How can every individual contribute to water conservation in daily life?
