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Dams (Disadvantages (Damming of rivers causes poor sediment flow causing…
Dams
Disadvantages
Damming of rivers causes poor sediment flow causing excessive sedimentation at the bottom of the reservoir
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Dams fragment rivers making it difficult for the aquatic fauna (fishes) to migrate for spawning (lay eggs)
The reservoirs also submerge the existing vegetation leading to its decomposition over a period of time
Irrigation has changed the cropping pattern of many farmers - they have shifted to water intensive commercial crops
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In Gujarat, the farmers of the Sabarmati basin agitated over the higher priority given to water supply to urban areas especially during drought almost causing a riot
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In 2006, release of water from dams during heavy rains aggravated the flood situation in Maharashtra & Gujarat
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Due to sedimentation, the flood plains are deprived of silt, a natural fertilizer
Multi-purpose projects are also known to cause earthquakes, water-borne diseases , increase pests and pollution
Advantages
Traditionally dams were built to impound rivers and rain water that could be later used for irrigation
Today dams have many uses - irrigation, electricity generation, water for domestic & industrial use, flood control, recreation, inland navigation, fish breeding etc
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The Bhakra Nangal project in the Sutluj-Beas river basin is used for electricity generation & irrigation
The Hirakud project in the Mahanadi river basin is used for electricity generation, irrigation & flood control
Nehru called dams " the temples of modern India" as it supported development of agriculture, village economy, rapid industrialization & urban economy
A dam is a barrier across flowing water that obstructs or retards (slows down) flow often creating a reservoir
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