Original CAPF digest of India's drainage: the Himalayan and Peninsular river systems, the major rivers and tributaries, lakes and the river-water disputes
India's rivers fall into two great groups, Himalayan (perennial, fed by snowmelt and rain) and Peninsular (mostly seasonal, fed by rain). Most drain into the Bay of Bengal; the Indus, Narmada, Tapi and the rivers of the western coast drain into the Arabian Sea.
These are older than the mountains in places (antecedent), cut deep gorges, and carry heavy silt to build large plains and deltas.
Older, with graded, shallow valleys; rain-fed and seasonal. Most flow east into the Bay of Bengal; two major ones flow west through rift valleys into the Arabian Sea.
| River | Source | Mouth | Notes |
|---|---|---|---|
| Mahanadi | Chhattisgarh | Bay of Bengal | Hirakud dam. |
| Godavari | Trimbak, Maharashtra | Bay of Bengal | The longest Peninsular river ("Dakshin Ganga"); tributaries include the Pranhita, Indravati, Manjira. |
| Krishna | Mahabaleshwar | Bay of Bengal | Tributaries: Tungabhadra, Bhima, Koyna. |
| Kaveri (Cauvery) | Brahmagiri (Karnataka) | Bay of Bengal | Subject of the long Karnataka-Tamil Nadu water dispute; the Sivasamudram falls. |
| Narmada | Amarkantak | Arabian Sea (Gulf of Khambhat) | Flows west through a rift valley; the Sardar Sarovar project; Marble Rocks, Dhuandhar falls. |
| Tapi (Tapti) | Satpura (Madhya Pradesh) | Arabian Sea | Flows west through a rift valley, parallel to the Narmada. |
The Narmada and Tapi flow westward through rift valleys (between the Vindhyas and Satpuras), which is why, unlike most peninsular rivers, they do not form deltas but estuaries.
Inter-state river-water disputes are adjudicated under the Inter-State River Water Disputes Act, 1956 (tribunals): the Kaveri (Karnataka-Tamil Nadu-Kerala-Puducherry), the Krishna, the Ravi-Beas (Punjab-Haryana) and the Mahadayi are recurring examples. Article 262 of the Constitution empowers Parliament to provide for such adjudication. This is a strong polity-geography crossover for the essay and interview.
Rivers are at the heart of two security-sensitive issues: the Indus Waters Treaty (1960) with Pakistan, periodically strained, and the management of the Brahmaputra, whose upper course lies in China, raising trans-boundary data-sharing and dam-building concerns. River floods (Kosi, Brahmaputra) are perennial disaster-management challenges that draw in the CAPFs and the NDRF.