Geography · Ch 12 — Water Resources
Surface Water Resources
Surface Water Resources
Surface Water Resources
Surface water is the water that collects on the ground — in rivers, lakes, ponds, and tanks. India’s surface water comes from four major sources: rivers, lakes, ponds, and tanks. Among these, rivers are the most dominant.
The country has about 10,360 rivers and their tributaries, each longer than 1.6 km. The total mean annual flow in all river basins across India is estimated at 1,869 cubic kilometres. However, not all of this water can be used. Only about 690 cubic kilometres of this flow can be put to beneficial use, due to constraints like topography, seasonal variation, and the location of demand.
The utilizable surface water resource of India is 690 cubic kilometres per year — less than half of the total annual river flow.
Along the coast, especially in states like Kerala, Odisha, and West Bengal, lagoons and lakes have formed. These water bodies are generally brackish (salty, but less than seawater). Despite the salinity, they are valuable resources. People use them for fishing and for irrigating certain varieties of paddy crops and coconut. This shows how even brackish surface water supports local livelihoods and agriculture in coastal regions. …
This map is a schematic outline of India showing the country’s major river basins, divided into two categories: those that flow west into the Arabian Sea and those that flow east into the Bay of Bengal. The map is not drawn to scale, but it includes a latitude–longitude grid from 68°E to 96°E and 8°N to 36°N, with the Tropic of Cancer marked across central India. A north arrow and a 0–600 km scale bar are provided for orientation.
The neighbouring countries are labelled: Afghanistan, Pakistan, China (Tibet), Nepal, Bhutan, Bangladesh, Myanmar, and Sri Lanka. The surrounding water bodies — the Arabian Sea, Bay of Bengal, and Indian Ocean — are also named. India’s island territories, Lakshadweep and the Andaman & Nicobar Islands, are labelled as well.
The river basins themselves are shaded in two tones. Dark grey indicates West Flowing basins, and light grey indicates East Flowing basins. The following basins are individually labelled:
- West Flowing: Indus Basin, Sabarmati Basin, Mahi Basin, Narmada Basin, Tapi Basin.
- East Flowing: Ganga Basin, Brahmaputra Basin, Barak Basin, Mahanadi Basin, Brahmani and Baitarni Basin, Subarnarekha Basin, Godavari Basin, Krishna Basin, Pennar Basin, Kaveri Basin.
Four callout boxes with arrows provide additional grouping:
- West Flowing Rivers Group 1: rivers in Kachchh, Saurashtra, and the Luni River.
- West Flowing Rivers Group 2: rivers south of the Tapi.
- East Flowing Rivers Group 1: rivers between the Mahanadi and Pennar.
- East Flowing Rivers Group 2: rivers between Pennar and Kanniyakumari.
The map does not show every river or tributary — it is a basin-level overview. The grouping callouts help you see that not all west-flowing rivers are in one region; they are scattered from the northwest (Indus, Luni) to the south of Tapi. Similarly, east-flowing rivers cover a vast stretch from the Ganga–Brahmaputra in the north to the Kaveri in the south. …