Q1. [4] deep exam-ready
Read the following and answer the questions:
After Independence, India invested heavily in multi-purpose river projects. The Bhakra–Nangal project in the Sutluj–Beas basin was used for both hydel power and irrigation. The Hirakud project on the Mahanadi was meant to integrate water conservation with flood control. The Sardar Sarovar on the Narmada was designed to serve four states — Maharashtra, Madhya Pradesh, Gujarat and Rajasthan — providing irrigation to millions of hectares and ensuring water supply to drought-prone and desert areas. However, critics point out that large reservoirs submerge vegetation, disrupt fish migration, cause sedimentation, and have even triggered earthquakes and water-borne diseases. The Damodar, once nicknamed the 'river of sorrow', saw its valley project built to tame its floods — yet the dams have at times triggered floods through excessive sedimentation in the reservoir.
(i) Name two purposes served by the Bhakra–Nangal project. (1 mark)
(ii) How does sedimentation in a reservoir ironically cause the very problem the dam was built to prevent? (1 mark)
(iii) Why are large dams said to fragment rivers, and what impact does this have on aquatic life? (1 mark)
(iv) Despite its benefits, why has the Sardar Sarovar project faced opposition? Suggest one valid concern. (1 mark)
Generated by claude-sonnet-4-6 · 2026-06-26 13:32 · grounding rag
Model Answer
(i) The Bhakra–Nangal project serves two purposes: hydel (hydroelectric) power production and irrigation.
(ii) Excessive sedimentation accumulates at the bottom of the reservoir, reducing its water-holding capacity. This causes water to overflow the dam during heavy rainfall, triggering floods — the very problem the dam was meant to prevent.
(iii) Large dams fragment rivers by blocking the continuous flow of water, creating barriers. This disrupts the migration of aquatic fauna, especially for spawning (breeding), threatening fish populations and disturbing the river's aquatic ecosystem.
(iv) The Sardar Sarovar project faces opposition because large reservoirs submerge existing vegetation and soil, leading to decomposition. One valid concern is displacement of local and tribal communities whose lands are submerged, causing loss of livelihood and habitat.
Source: Chapter 3 — Multi-purpose River Projects and Integrated Water Resources Management
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Explanation
- (i) Direct answer from the textbook; name both purposes clearly.
- (ii) The key word is "ironically" — examiners want you to show the cause-effect chain: sedimentation → reduced capacity → overflow → floods.
- (iii) Use the term "spawning" as it appears in the source; it shows precise textbook knowledge.
- (iv) The passage mentions submergence of vegetation; displacement is a widely accepted concern from the chapter context. State one concern clearly — don't list many vaguely.