Water Resources
"Water, water EVERYWHERE, nor any drop to drink." — Coleridge. India has 18% of the world's population but only 4% of the world's freshwater. This IS the water crisis.
1. Water Scarcity — Causes
'Water scarcity is NOT just about PHYSICAL shortage. It is about POOR MANAGEMENT, POLLUTION, and UNEQUAL distribution.'
Causes of Water Scarcity in India
| Cause | Explanation |
|---|---|
| Population growth | More people = MORE demand for drinking, agriculture, industry |
| Agricultural demand | ~85% of India's freshwater is used for agriculture (HIGHLY water-intensive crops like sugarcane, paddy) |
| Industrialisation | Factories use HUGE amounts of water and OFTEN dump untreated waste |
| Urbanisation | Cities suck water from surrounding areas (Bangalore: 200 km pipeline from Cauvery) |
| Over-exploitation of groundwater | India is the LARGEST extractor of groundwater in the WORLD. Tube wells are DEEPENING every year. |
| Water pollution | Rivers carry SEWAGE, industrial waste, chemicals. Ganga, Yamuna are SEVERELY polluted. |
| Climate change | Erratic monsoon — floods in some regions, DROUGHTS in others. LESS snowfall → less river flow in summer. |
| Wastage | UP TO 60% of irrigation water is LOST due to inefficient methods (flood irrigation). |
Common Mistake: Many students say 'India has low rainfall' — FALSE. India's AVERAGE rainfall is ~1,170 mm (one of the HIGHEST in the world). The problem is UNEVEN distribution (Rajasthan: <100 mm, Meghalaya: >1,000 cm).
2. Multi-Purpose River Projects and Dams
2.1 What Are Multi-Purpose Projects?
Dams that serve MULTIPLE functions: irrigation, hydroelectricity, flood control, drinking water, navigation, recreation.
| Project | River | State | Key Feature |
|---|---|---|---|
| Bhakra Nangal | Sutlej | Punjab, HP, Rajasthan | Highest in India (226 m). 'Temple of Resurgent India' — Nehru. |
| Hirakud | Mahanadi | Odisha | Longest dam in India (4.8 km). |
| Damodar Valley (DVC) | Damodar | Jharkhand, WB | Modelled on TVA (USA). Flood control + power. |
| Sardar Sarovar | Narmada | Gujarat, MP, Maharashtra | LARGEST dam in Narmada Valley project. Highly controversial. |
| Tehri | Bhagirathi | Uttarakhand | Tallest dam in India (260.5 m). |
| Nagarjuna Sagar | Krishna | AP, Telangana | One of the LARGEST masonry dams in the world. |
2.2 Dams — Advantages and Disadvantages
| Advantages | Disadvantages |
|---|---|
| IRRIGATION — year-round water for farming | DISPLACEMENT — millions of tribals and farmers lose homes (largest impact) |
| HYDROELECTRICITY — clean, renewable energy | SUBMERGENCE — forests, fertile land, villages go underwater |
| FLOOD CONTROL — regulates river flow | SILTATION — reservoirs fill with silt, REDUCING lifespan |
| DRINKING WATER supply to cities | SEISMIC RISK — large reservoirs can trigger earthquakes |
| NAVIGATION — inland waterways | WATERLOGGING and SALINISATION in surrounding areas |
| TOURISM and recreation | RIVER ECOSYSTEM disrupted — fish migration blocked, deltas SHRINK |
2.3 Narmada Bachao Andolan (NBA)
- MOVEMENT against Sardar Sarovar Dam on the Narmada River.
- LED by Medha Patkar and Baba Amte.
- Key demand: ADEQUATE rehabilitation for displaced families.
- Slogan: 'Kyon banaye bandh, hum sab ko hai andh?' (Why build dams when we are all blind?).
- Outcome: Supreme Court (2000) allowed construction BUT ordered proper R&R (Rehabilitation and Resettlement).
- Moral: Development MUST not come at the cost of human lives and dignity.
3. Rainwater Harvesting
'Rainwater harvesting is the COLLECTION and STORAGE of rainwater for REUSE, rather than letting it run off.'
3.1 Traditional Rainwater Harvesting Methods in India
| Method | Region | How It Works |
|---|---|---|
| Kunds | Rajasthan (Thar Desert) | Covered underground TANK. Collects rainwater from rooftops or specially prepared catchments. Water stays COOL and CLEAN. |
| Tankas | Rajasthan, Gujarat | Traditional TANKS for storing drinking water. Often part of stepwells (baolis). |
| Rooftop harvesting | Urban areas (pan-India) | Rain from roof → pipes → filter → storage tank OR recharge pit. RECHARGES groundwater. |
| Bawdis (stepwells) | Rajasthan, Delhi, Gujarat | Stepped wells that TAP groundwater AND collect rainwater. |
| Kuls / Kuhls | Himachal Pradesh, Uttarakhand | Small DIVERSIFIED channels carry glacial meltwater to villages. |
| Eri / Tank systems | Tamil Nadu, AP | Network of interconnected TANKS that store monsoon rain for irrigation. |
| Virdas | Gujarat (Kutch, Banni grasslands) | Shallow wells in LOW-lying areas that FRESHWATER floats on top of saline water. |
3.2 Why Rainwater Harvesting Matters
- RECHARGES groundwater (critical in over-exploited areas).
- REDUCES urban flooding.
- IMPROVES water quality (dilutes contaminants).
- PROVIDES WATER in water-scarce months.
- LOW-COST and community-driven.
4. AP Context
4.1 Krishna-Godavari Water Disputes
- Krishna Water Disputes Tribunal (KWDT): Dispute among AP, Telangana, Maharashtra, Karnataka. AP claimed MORE water from Krishna based on HISTORICAL usage and catchment area.
- Godavari Water Disputes Tribunal (GWDT): AP vs. Maharashtra, Karnataka, MP, Odisha. Godavari is the LARGEST river in peninsular India.
- KEY ISSUE: The 2014 bifurcation of AP created NEW complexities. Telangana demanded REALLOCATION of Krishna waters. The disputes are STILL ongoing in the Supreme Court.
4.2 Polavaram Project (Indira Sagar)
- River: Godavari (West Godavari district, AP).
- Purpose: IRRIGATION (2.9 lakh acres), drinking water (to Visakhapatnam), hydroelectricity (960 MW).
- Controversy: SUBMERGES 276 villages across AP, Odisha, Chhattisgarh. MAJOR displacement of tribal communities (Koya, Reddy, Konda Reddi).
- NATIONAL project status — Central government funds it.
- Environmental concern: Submerges PAPIKONDA National Park (WILDLIFE sanctuary) — habitat of tigers, crocodiles.
4.3 Traditional Tank Systems in AP
- AP has THOUSANDS of traditional irrigation TANKS (cheruvu).
- These TANKS collect monsoon rain → recharge groundwater → irrigate rabi crops.
- DECLINE due to: neglect, encroachment, siltation, lack of community maintenance.
- Revival efforts: Neeru-Chettu programme (AP govt) — desilting tanks, restoring water bodies.
5. Exam Focus
| Topic | Marks | Frequency |
|---|---|---|
| Water scarcity — causes | 3 marks | HIGH |
| Multi-purpose projects — advantages/disadvantages | 3–5 marks | HIGH |
| Narmada Bachao Andolan | 2–3 marks | Medium |
| Rainwater harvesting methods (tankas, kunds) | 3 marks | HIGH |
| AP-specific: Polavaram, Krishna-Godavari disputes | 3–5 marks | HIGH (state board) |
6. Quick Self-Test
Q1. What are THREE causes of water scarcity in India? A. Population growth, over-exploitation of groundwater, water pollution (any three: agricultural demand, industrialisation, climate change, wastage).
Q2. State TWO advantages and TWO disadvantages of multi-purpose dams. A. Advantages: irrigation + hydroelectricity. Disadvantages: displacement of people + submergence of forests/land.
Q3. What was the NARMADA BACHAO ANDOLAN and who led it? A. Movement against Sardar Sarovar Dam. Led by Medha Patkar and Baba Amte. Demanded proper rehabilitation of displaced families.
Q4. How does ROOFTOP RAINWATER HARVESTING work? A. Rainwater from roof → pipes → filter (to remove debris) → storage tank OR recharge pit (to replenish groundwater).
Q5. Why does India face water scarcity despite HIGH average rainfall? A. Rainfall is UNEVENLY distributed (Rajasthan to Meghalaya). Seasonal concentration (monsoon: 4 months). Wastage and pollution worsen it.
Q6. What is the Polavaram Project and why is it controversial? A. Multipurpose project on Godavari (AP). Controversial because it SUBMERGES 276 villages, displaces tribals, and floods Papikonda National Park.
Q7. Give ONE traditional water harvesting method used in Rajasthan. A. Kund / Tanka — covered underground tanks to store rainwater from rooftops in ARID regions.
7. Common Mistakes & Fixes
| Mistake | Fix |
|---|---|
| 'India has less rainfall' | India has ~1,170 mm average (HIGH). Problem is UNEVEN distribution. |
| Confusing Bhakra Nangal with Hirakud | Bhakra = Sutlej (Punjab). Hirakud = Mahanadi (Odisha). Bhakra is HIGHEST, Hirakud is LONGEST. |
| Thinking NBA is only about Sardar Sarovar | NBA began with Sardar Sarovar but LATER opposed ALL dams on Narmada. |
| 'Dams are always good' | Dams have MAJOR social and environmental costs — displacement, siltation, seismic risk. |
| Mixing kund and tanka | Kund = from rooftop/catchment (covered). Tanka = traditional storage tank (often in stepwells). Both are from Rajasthan. |
