Extent of Usability of River Water

The central question this section raises is deceptively simple: India's rivers carry enormous volumes of water every year, yet the country faces both floods and droughts, often at the same time in different regions. The problem is not merely the total availability of water, but its distribution — both across the seasons and across the geography of the nation.

Some rivers are perennial, flowing throughout the year, while non-perennial rivers run nearly dry in the summer months. During the rainy season, a large share of this water is lost to floods and simply flows out to the sea. Meanwhile, even as one part of the country drowns in floodwater, another region suffers from acute drought. This paradox forces a genuine question: is India's water crisis a problem of availability, or a problem of management?

The section invites you to think about whether these simultaneous problems can be mitigated by transferring surplus water from basins that have too much to basins that have too little. This is the idea behind inter-basin linkage — moving water from one river basin to another through canals. Several schemes illustrate this approach:

• Periyar Diversion Scheme — one of the earliest examples of transferring water across basins.
• Indira Gandhi Canal Project — carries water to arid regions of Rajasthan.
• Kurnool-Cuddapah Canal — links rivers in Andhra Pradesh.
• Beas-Satluj Link Canal — connects two tributaries of the Indus system.
• Ganga-Kaveri Link Canal — a proposed link between the northern and southern river systems.

But the book pushes you to think critically about such projects. Digging a canal is not enough. The terrain is uneven — much of peninsular India is a plateau, while the northern plains are flat. How would water be lifted from the plains to the plateau? Is there genuinely surplus water in the northern rivers that could be transferred on a regular basis without harming their own ecosystems? These are the practical difficulties that any river-linking scheme must confront.

The section then turns to the major peninsular rivers, giving their essential details. The Godavari is the largest of the east-flowing peninsular rivers. Its principal tributaries include the Pranhita and the Manjra. It is prone to heavy floods in its lower reaches, south of Polavaram, where it cuts through a picturesque gorge. It is navigable only in its deltaic stretch; after Rajahmundry, it splits into several branches and forms a large delta.

The Krishna is the second largest east-flowing peninsular river. It rises near Mahabaleshwar in the Sahyadri hills and has a total length of 1,401 km. Its major tributaries are the Koyna, the Tungabhadra and the Bhima. Of its total catchment area, 27 per cent lies in Maharashtra, 44 per cent in Karnataka, and 29 per cent in Andhra Pradesh and Telangana.

The Kaveri rises in the Brahmagiri hills (at an elevation of 1,341 m) in the Kodagu district of Karnataka. It is 800 km long and drains an area of 81,155 sq km. What makes it distinctive is its rainfall pattern: the upper catchment receives rain during the southwest monsoon (summer), while the lower part receives rain during the northeast monsoon (winter). As a result, the Kaveri carries water throughout the year with far less fluctuation than other peninsular rivers. About 3 per cent of its basin lies in Kerala, 41 per cent in Karnataka, and 56 per cent in Tamil Nadu. Its important tributaries are the Kabini, the Bhavani and the Amravati.

The Narmada originates on the western flank of the Amarkantak plateau at a height of about 1,057 m. It flows in a rift valley, with the Satpura range to the south and the Vindhyan range to the north. Near Jabalpur, it forms a picturesque gorge in marble rocks and the Dhuandhar waterfall. After flowing about 1,312 km, it meets the Arabian Sea south of Bharuch, forming a broad estuary about 27 km long. Its catchment area is roughly 98,796 sq km. The Sardar Sarovar Project has been constructed on this river. The book also mentions the Narmada river conservation mission, "Namami Devi Narmade," and encourages you to gather information about it and discuss it with peers.

The section closes with a frank discussion of the problems in using river water. You are asked to rank the following issues:

1. No availability in sufficient quantity
2. River water pollution
3. Load of silt in the river water
4. Uneven seasonal flow of water
5. River water disputes between states
6. Shrinking of channels due to the extension of settlements towards the thalweg …