📌 Topic 06 of 6 · Chapter 02 · Drainage Systems
River Basins, Interlinking & Quick Revision
River basin areas, interlinking of rivers, water disputes, complete chapter revision — UPSC & PSC exams.
📊 Major River Basins of India — Area Ranking
| Rank | River Basin | Area (sq km) | Key States |
|---|---|---|---|
| 1 | Ganga Basin | ~8,61,404 | UP, Bihar, WB, MP, Rajasthan, Uttarakhand |
| 2 | Indus Basin | ~3,21,289 | J&K, Ladakh, Punjab, Himachal Pradesh |
| 3 | Godavari Basin | ~3,12,812 | Maharashtra, Telangana, AP, Chhattisgarh, Odisha |
| 4 | Krishna Basin | ~2,58,948 | Maharashtra, Karnataka, Andhra Pradesh |
| 5 | Mahanadi Basin | ~1,41,589 | Chhattisgarh, Odisha |
| 6 | Narmada Basin | ~98,796 | MP, Maharashtra, Gujarat |
| 7 | Cauvery Basin | ~81,155 | Karnataka, Tamil Nadu, Kerala |
| 8 | Brahmaputra Basin | ~1,94,413 (India) | Arunachal Pradesh, Assam |
🔗 Interlinking of Rivers
The National River Linking Project (NRLP) aims to transfer water from surplus river basins to deficit basins through a network of canals and reservoirs.
- Proposed by: National Water Development Agency (NWDA)
- Two components: Himalayan Component (14 links) + Peninsular Component (16 links)
- Ken-Betwa Link: First interlinking project approved; connects Ken river (MP) to Betwa river (UP); benefits Bundelkhand region
- Benefits: Flood control, drought mitigation, irrigation, hydropower
- Concerns: Environmental impact, displacement, interstate disputes, cost
⚖️ Major Inter-State Water Disputes
| Dispute | States Involved | River | Status |
|---|---|---|---|
| Cauvery Water Dispute | Karnataka vs Tamil Nadu (+ Kerala, Puducherry) | Cauvery | SC verdict 2018; Cauvery Water Management Authority formed |
| Krishna Water Dispute | Maharashtra, Karnataka, AP, Telangana | Krishna | Krishna Water Disputes Tribunal (KWDT-II) |
| Godavari Water Dispute | Maharashtra, AP, Telangana, Odisha, MP | Godavari | Godavari Water Disputes Tribunal |
| Narmada Water Dispute | MP, Gujarat, Maharashtra, Rajasthan | Narmada | Narmada Water Disputes Tribunal (1969); Sardar Sarovar height dispute |
| Ravi-Beas Water Dispute | Punjab vs Haryana | Ravi, Beas | SYL (Sutlej-Yamuna Link) canal dispute; unresolved |
🌊 Important Dams of India
| Dam | River | State | Key Fact |
|---|---|---|---|
| Tehri Dam | Bhagirathi | Uttarakhand | Highest dam in India (~261m); one of world’s highest |
| Bhakra Nangal | Sutlej | HP/Punjab | Largest hydroelectric project; “Temple of Modern India” (Nehru) |
| Sardar Sarovar | Narmada | Gujarat | Largest dam by volume in India; Statue of Unity nearby |
| Hirakud | Mahanadi | Odisha | Longest dam in India (~4.8 km) |
| Nagarjuna Sagar | Krishna | Telangana/AP | World’s largest masonry dam |
| Mettur Dam | Cauvery | Tamil Nadu | Largest dam in Tamil Nadu; Stanley Reservoir |
| Idukki Dam | Periyar | Kerala | Largest arch dam in Asia |
✅ Chapter 02 — Complete Revision Checklist
✅ Himalayan rivers = perennial + antecedent; Peninsular rivers = seasonal + consequent
✅ Indus origin = Mansarovar Lake (Tibet); enters India through Ladakh
✅ Indus Waters Treaty (1960) = India: Ravi, Beas, Sutlej; Pakistan: Indus, Jhelum, Chenab
✅ Ganga = longest river in India (2,525 km); origin = Gangotri glacier
✅ Triveni Sangam = Ganga + Yamuna + Saraswati = Prayagraj
✅ Kosi = “Sorrow of Bihar”; Damodar = “Sorrow of Bengal”
✅ Sundarbans = world’s largest delta = Ganga + Brahmaputra = India + Bangladesh
✅ Brahmaputra = Tsangpo (Tibet) → Dihang (Arunachal) → Brahmaputra (Assam) → Jamuna (Bangladesh)
✅ Dihang gorge = deepest gorge in world (~5,500m)
✅ Majuli Island = world’s largest river island = Brahmaputra = Assam
✅ Godavari = longest peninsular river (1,465 km) = “Dakshin Ganga”
✅ Narmada + Tapi = flow west = rift valleys = form estuaries (not deltas)
✅ Hirakud dam = longest dam in India = Mahanadi = Odisha
✅ Tehri dam = highest dam in India = Bhagirathi = Uttarakhand
✅ Nagarjuna Sagar = world’s largest masonry dam = Krishna river
✅ Cauvery dispute = Karnataka vs Tamil Nadu = SC verdict 2018
✅ Ganga basin = largest river basin in India
✅ Ken-Betwa = first approved river interlinking project
✅ Indus origin = Mansarovar Lake (Tibet); enters India through Ladakh
✅ Indus Waters Treaty (1960) = India: Ravi, Beas, Sutlej; Pakistan: Indus, Jhelum, Chenab
✅ Ganga = longest river in India (2,525 km); origin = Gangotri glacier
✅ Triveni Sangam = Ganga + Yamuna + Saraswati = Prayagraj
✅ Kosi = “Sorrow of Bihar”; Damodar = “Sorrow of Bengal”
✅ Sundarbans = world’s largest delta = Ganga + Brahmaputra = India + Bangladesh
✅ Brahmaputra = Tsangpo (Tibet) → Dihang (Arunachal) → Brahmaputra (Assam) → Jamuna (Bangladesh)
✅ Dihang gorge = deepest gorge in world (~5,500m)
✅ Majuli Island = world’s largest river island = Brahmaputra = Assam
✅ Godavari = longest peninsular river (1,465 km) = “Dakshin Ganga”
✅ Narmada + Tapi = flow west = rift valleys = form estuaries (not deltas)
✅ Hirakud dam = longest dam in India = Mahanadi = Odisha
✅ Tehri dam = highest dam in India = Bhagirathi = Uttarakhand
✅ Nagarjuna Sagar = world’s largest masonry dam = Krishna river
✅ Cauvery dispute = Karnataka vs Tamil Nadu = SC verdict 2018
✅ Ganga basin = largest river basin in India
✅ Ken-Betwa = first approved river interlinking project