1. Introduction – Water as a Resource
Three-fourth of the earth’s surface is covered with water, but only a small proportion accounts for freshwater that can be put to use. This freshwater is mainly obtained from surface run-off and ground water that is continually renewed through the hydrological cycle. All water moves within the hydrological cycle — ensuring water is a renewable resource.
📌 Key Prediction
By 2025, nearly two billion people will live in absolute water scarcity (NCERT).
Water availability varies over space and time, mainly due to variations in seasonal and annual precipitation. However, water scarcity in most cases is caused by over-exploitation, excessive use and unequal access to water among different social groups — not just low rainfall.
2. Water Scarcity – Causes and Dimensions
Fig. 3.1: Water Scarcity — ‘Water, Water Everywhere, Not a Drop to Drink’ (NCERT)
Left: Boy collects drinking water after heavy rains in Kolkata (record 180 mm rainfall). Bottom left: Kashmiri earthquake survivor carries water in snow. Right: Women queue for water in Rajasthan.
Left: Boy collects drinking water after heavy rains in Kolkata (record 180 mm rainfall). Bottom left: Kashmiri earthquake survivor carries water in snow. Right: Women queue for water in Rajasthan.
Causes of Water Scarcity
| Cause | Explanation |
|---|---|
| Large & growing population | More water needed for domestic use and food production; irrigated agriculture is the largest consumer of water |
| Over-exploitation of groundwater | Farmers digging wells and tube-wells → falling groundwater levels → threat to food security |
| Industrialisation | Industries are heavy users of water; also require hydroelectric power; MNCs increasing pressure on freshwater |
| Urbanisation | Dense urban populations; housing societies use groundwater pumping devices → depletion in cities |
| Water pollution | Domestic and industrial wastes, chemicals, pesticides, fertilisers — making water hazardous even where ample water exists |
| Unequal access | Rich areas/social groups access more water; marginalised communities lack access even in water-rich regions |
🔵 Jal Jeevan Mission (JJM)
Goal: Enable every rural household to get assured supply of potable piped water at 55 litres per capita per day regularly on a long-term basis by ensuring functionality of tap water connections.
Source: Economic Survey 2020–21, p.357
Source: Economic Survey 2020–21, p.357
Atal Bhujal Yojana (Atal Jal) – NCERT ‘Do You Know’ Box (Source: Ministry of Jal Shakti, GoI 2022-23)
📗 Atal Bhujal Yojana (Atal Jal) – NCERT ‘Do You Know’
Implemented in 8,220 water-stressed Gram Panchayats of 229 administrative blocks/talukas in 80 districts of seven states: Gujarat, Haryana, Karnataka, Madhya Pradesh, Maharashtra, Rajasthan, and Uttar Pradesh. These states account for about 37% of the total number of water-stressed (over-exploited, critical and semi-critical) blocks in India. Key aspect: bring behavioural changes — from consumption to conservation and smart water management.
Source: Annual Report, Ministry of Jal Shakti, GoI 2022-23
Source: Annual Report, Ministry of Jal Shakti, GoI 2022-23
3. Hydraulic Structures in Ancient India (NCERT Sidebar)
Archaeological and historical records show India’s long tradition of sophisticated hydraulic structures:
| Period / Century | Structure / Achievement | Location |
|---|---|---|
| 1st Century B.C. | Sophisticated water harvesting system channelling flood water of the Ganga | Sringaverapura, near Allahabad |
| Chandragupta Maurya era | Dams, lakes and irrigation systems extensively built | Pan-India |
| Ancient period | Sophisticated irrigation works | Kalinga (Odisha), Nagarjunakonda (AP), Bennur (Karnataka), Kolhapur (Maharashtra) |
| 11th Century | Bhopal Lake — one of the largest artificial lakes of its time | Bhopal |
| 13th–14th Century | Tank in Hauz Khas constructed by Allauddin Khilji (Khalji) for supplying water to Siri Fort area | Delhi |
Source: Dying Wisdom, CSE, 1997
4. Multi-Purpose River Projects and Integrated Water Resources Management
Dams were traditionally built to impound rivers and rainwater for irrigation. Today, dams are built for multiple purposes — hence called multi-purpose projects.
🔵 Definition of a Dam (NCERT)
A dam is a barrier across flowing water that obstructs, directs or retards the flow, often creating a reservoir, lake or impoundment. “Dam” refers to the reservoir rather than the structure. Dams are classified by: structure (timber, embankment, masonry), purpose, or height (low, medium, high / large and major dams).
Uses of Multi-Purpose Projects
- Irrigation
- Electricity generation (hydel power)
- Water supply for domestic and industrial uses
- Flood control
- Recreation
- Inland navigation
- Fish breeding
Key Multi-Purpose Projects
| Project | River / Basin | State(s) | Key Use |
|---|---|---|---|
| Bhakra-Nangal | Sutluj-Beas river basin | Punjab/HP | Hydel power + irrigation |
| Hirakud | Mahanadi basin | Odisha | Conservation + flood control |
| Sardar Sarovar | Narmada River | Gujarat (+ Maharashtra, MP, Rajasthan) | Drought-prone area irrigation; 18.45 lakh ha in Gujarat; 2,46,000 ha in Rajasthan desert districts; 37,500 ha in tribal Maharashtra |
💬 Jawaharlal Nehru’s Quote
Nehru proudly proclaimed dams as the ‘temples of modern India’ — integrating development of agriculture and the village economy with rapid industrialisation and growth of the urban economy.
🎵 Bhadu Song – Damodar Valley (NCERT Sidebar)
“Oh! Damodar, we fall at your feet / Reduce the floods a little…” — This popular Bhadu song from the Damodar valley region narrates the troubles faced by people owing to the flooding of Damodar river, known as the ‘river of sorrow’.
India: Major Rivers and Dams (NCERT)
Disadvantages / Problems of Multi-Purpose Projects
| Problem | Explanation |
|---|---|
| Poor sediment flow | Regulating rivers → excessive sedimentation at bottom of reservoir → rockier stream beds → poorer aquatic habitats |
| Fragmentation of rivers | Difficult for aquatic fauna to migrate, especially for spawning |
| Submergence of vegetation | Reservoirs on floodplains submerge vegetation and soil → decomposition |
| Floods triggered | Ironically, dams built to control floods have triggered floods due to sedimentation; mostly unsuccessful in excessive rainfall events |
| Soil erosion | Floods caused extensive soil erosion; flood plains deprived of silt (natural fertiliser) → land degradation |
| Induced earthquakes | Multi-purpose projects observed to induce earthquakes |
| Water-borne diseases | Caused water-borne diseases, pests and pollution from excessive water use |
| Changed cropping pattern | Farmers shifting to water-intensive and commercial crops → salinisation of soil |
| Displacement | Large-scale displacement of people; loss of livelihood |
| Inter-state disputes | E.g., Krishna-Godavari dispute — Karnataka and AP objected to Maharashtra’s diversion of more water at Koyna |
📗 Pradhan Mantri Krishi Sinchayee Yojana (PMKSY)
Objectives: Enhance physical access of water on the farm; expand cultivable area under assured irrigation (Har Khet Ko Pani); improve on-farm water use efficiency (Per Drop More Crop); introduce sustainable water conservation practices.
🔵 Sardar Sarovar Dam – Key Facts (NCERT ‘Do You Know’)
Built over the Narmada River in Gujarat. One of the largest water resource projects of India — covering four states: Maharashtra, Madhya Pradesh, Gujarat, Rajasthan. Will provide irrigation to 18.45 lakh ha covering 3,112 villages in 15 districts of Gujarat; 2,46,000 ha in desert districts of Barmer and Jalore (Rajasthan); 37,500 ha in tribal hilly tract of Maharashtra. About 75% of command area in Gujarat is drought-prone; entire command in Rajasthan is drought-prone. Source: Sardar Sarovar Narmada Nigam Ltd.
5. Rainwater Harvesting – Traditional and Modern Methods
Water harvesting system was considered a viable alternative — both socio-economically and environmentally — to multi-purpose projects. Ancient India had an extraordinary tradition of water-harvesting alongside sophisticated hydraulic structures.
Traditional Water Harvesting Techniques (Region-wise)
| Region / State | Traditional Method | Purpose |
|---|---|---|
| Hill and mountainous regions (Western Himalayas) | Guls / Kuls — diversion channels | Agriculture |
| Rajasthan (general) | Rooftop rainwater harvesting using ‘matkas’ | Drinking water storage |
| Rajasthan — Bikaner, Phalodi, Barmer | Underground tanks — Tankas (built inside main house or courtyard; connected to sloping roofs via pipe) | Drinking water; first spell not collected (cleans roofs); subsequent showers stored |
| Jaisalmer, Rajasthan | Khadins — agricultural fields converted to rain-fed storage | Moisten soil for agriculture |
| Other parts of Rajasthan | Johads | Water storage |
| Bengal flood plains | Inundation channels | Irrigate fields |
| Meghalaya | Bamboo Drip Irrigation System (200-year-old) | Irrigation — tapping stream and spring water via bamboo pipes; 18–20 litres enters system; reduces to 20–80 drops/min at plant site |
📌 Tanka – Key Facts
Rainwater or ‘palar pani’ — considered the purest form of natural water in Rajasthan. One household in Phalodi had a tanka: 6.1 m deep, 4.27 m long, 2.44 m wide. Tankas stored water till next rainfall — reliable source when other sources dried up. Many houses built underground rooms adjoining the tanka to beat summer heat. In western Rajasthan today, practice is declining due to availability of water through the perennial Indira Gandhi Canal.
Fig. 3.7: Bamboo Drip Irrigation System, Meghalaya (NCERT) — A 200-year-old tradition of tapping spring water using bamboo pipes by gravity.
Modern Adaptations of Rainwater Harvesting
| Location | Method / Achievement |
|---|---|
| Gendathur village, Mysuru, Karnataka | ~200 households installed rooftop rainwater harvesting; village earns distinction of being ‘rich in rainwater’; annual precipitation 1,000 mm; 80% collection efficiency; ~10 fillings/year → each house collects ~50,000 litres; total from 200 houses = 1,00,000 litres |
| Shillong, Meghalaya | Rooftop rainwater harvesting is the most common practice; 15–25% of total household water need comes from it — despite Cherapunjee and Mawsynram (55 km away) receiving highest rainfall in world, Shillong faces acute water shortage |
| Tamil Nadu | First state in India to make rooftop rainwater harvesting structure compulsory for all houses; legal provisions to punish defaulters |
| Kaza village (Spiti) | A kul leads to a circular village tank; water released as and when required |
⚠️ Interesting Fact (NCERT) – Shillong Paradox
Cherapunjee and Mawsynram — situated just 55 km from Shillong — receive the highest rainfall in the world, yet the state capital Shillong faces acute shortage of water. This is a perfect example of water scarcity existing even in high rainfall areas — due to lack of storage and management.
6. NCERT Exercise Answers
MCQ 1(i) – Water Scarcity Classification
| Region | Status | Reason |
|---|---|---|
| (a) High annual rainfall | Not suffering | Adequate water availability |
| (b) High rainfall + large population | Suffering | Greater demand; over-exploitation; unequal access |
| (c) High rainfall but highly polluted water | Suffering | Qualitative scarcity — water unfit for use |
| (d) Low rainfall + low population | Not suffering | Demand matches limited supply |
MCQ 1(ii) – Not an Argument in Favour of Multi-Purpose Projects
Answer: (c) Multi-purpose projects lead to large scale displacements and loss of livelihood — this is a disadvantage/criticism, not an argument in favour.
1(iii) – Corrected False Statements
- Corrected (a): Multiplying urban centres with large and dense populations and urban lifestyles have added to water and energy requirements and further aggravated the problem of water scarcity — NOT helped in proper utilisation.
- Corrected (b): Regulating and damming of rivers does affect the river’s natural flow — causing poor sediment flow, excessive sedimentation and rockier stream beds.
- Corrected (c): Today in Rajasthan, the practice of rooftop rainwater harvesting is on the decline as plenty of water is available due to the perennial Indira Gandhi Canal — though some houses still maintain tankas.
How Water is a Renewable Resource
Water is renewed through the hydrological cycle — water evaporates from oceans, rivers and lakes, forms clouds, precipitates as rain/snow, runs off as surface run-off, infiltrates as groundwater, and returns to oceans — continually renewing itself.
📝 Practice MCQs – UPSC / State PCS Standard
Q1. Water scarcity in most cases is caused by which of the following?
- A. Low annual rainfall alone
- B. Absence of rivers and lakes
- C. Over-exploitation, excessive use and unequal access among different social groups
- D. Natural hydrological cycle imbalance
✅ Answer: C | Even high-rainfall areas can face water scarcity due to population pressure, pollution and unequal access — as evident from cities like Shillong.
Q2. The Bhakra-Nangal project is located on which river basin and serves which dual purpose?
- A. Mahanadi basin — flood control and irrigation
- B. Sutluj-Beas river basin — hydel power production and irrigation
- C. Narmada basin — drinking water and irrigation
- D. Godavari basin — hydropower and navigation
✅ Answer: B | The Hirakud project in Mahanadi basin integrates water conservation with flood control. Bhakra-Nangal is in Sutluj-Beas basin for hydel power + irrigation.
Q3. Which of the following is NOT a use of multi-purpose river projects?
- A. Flood control
- B. Fish breeding
- C. Inland navigation
- D. Mining of river bed minerals
✅ Answer: D | Multi-purpose projects serve: irrigation, electricity, domestic/industrial water supply, flood control, recreation, inland navigation, fish breeding. Mining is not a use.
Q4. ‘Palar Pani’ refers to which of the following?
- A. Canal water from Indira Gandhi Canal
- B. Groundwater in Rajasthan
- C. Rainwater — considered the purest form of natural water in Rajasthan
- D. River water from the Luni river
✅ Answer: C | ‘Palar pani’ is the local term for rainwater in Rajasthan, stored in underground tankas — regarded as the purest form of natural water.
Q5. Tamil Nadu’s distinction regarding rooftop rainwater harvesting is:
- A. It receives the highest rainfall and thus collects the most rainwater
- C. It is the first state in India to make rooftop rainwater harvesting compulsory for all houses with legal provisions to punish defaulters
- D. It invented the bamboo drip irrigation system
✅ Answer: C | Tamil Nadu made rooftop rainwater harvesting structure compulsory to all houses across the state — a landmark legal step in water conservation.
Q6. Ironically, dams built to control floods have sometimes triggered floods due to:
- A. Increased river velocity below the dam
- B. Sedimentation in the reservoir reducing its water-holding capacity
- C. Mismanagement of irrigation canals
- D. Seismic activities near the dam
✅ Answer: B | NCERT explicitly states dams triggered floods due to sedimentation in reservoir; big dams mostly unsuccessful in controlling floods during excessive rainfall.
Q7. The Bamboo Drip Irrigation System is a 200-year-old indigenous tradition of which state?
- A. Assam
- B. Manipur
- C. Meghalaya
- D. Nagaland
✅ Answer: C | In Meghalaya, bamboo pipes tap stream and spring water; 18–20 litres enters the system and reduces to 20–80 drops per minute at the plant site.
Q8. Consider these statements about Atal Bhujal Yojana:
1. It covers 8,220 Gram Panchayats in 80 districts of seven states.
2. These states account for about 37% of water-stressed blocks in India.
3. Its key goal is smart water management and shift from consumption to conservation.
Which are correct?
1. It covers 8,220 Gram Panchayats in 80 districts of seven states.
2. These states account for about 37% of water-stressed blocks in India.
3. Its key goal is smart water management and shift from consumption to conservation.
Which are correct?
- A. 1 and 2 only
- B. 2 and 3 only
- C. 1, 2 and 3
- D. 1 and 3 only
✅ Answer: C | All three statements are accurate as per NCERT ‘Do You Know’ box (Source: Annual Report, Ministry of Jal Shakti, GoI 2022-23).
Q9. Which of the following is correctly matched — Traditional water harvesting method and its region?
- A. Khadins — Bengal flood plains
- B. Guls/Kuls — Rajasthan arid region
- C. Johads — Rajasthan; Guls/Kuls — Western Himalayas
- D. Tankas — Meghalaya; Inundation channels — Rajasthan
✅ Answer: C | Johads and Khadins: Rajasthan | Guls/Kuls: Western Himalayas | Inundation channels: Bengal flood plains | Tankas: semi-arid Rajasthan (Bikaner, Phalodi, Barmer).
Q10. Which of the following is an ecological consequence of large-scale irrigation from multi-purpose projects?
- A. Increase in forest cover due to water availability
- B. Salinisation of soil due to shift to water-intensive crops
- C. Reduction in groundwater extraction
- D. Improvement in river aquatic biodiversity
✅ Answer: B | Irrigation changes cropping patterns; farmers shift to water-intensive and commercial crops → salinisation of soil is a major ecological consequence noted by NCERT.
