Question

What is the use of constructing multi purpose river valley projects?
A.To increase the navigability of the river.
B.To generate hydroelectricity
C.To control flood
D.All of the above

Answer 1

Hint: When Bhakra Nangal Dam was under construction, then Prime Minister, Jawaharlal Nehru called multi purpose river projects ‘ Temples of modern India’, due to the multiple purposes the dams served.

Complete answer:
Multipurpose river valley projects or commonly known as dams were launched after independence. These are built across rivers in order to provide water for multiple purposes. The name multipurpose project clearly suggests that these projects are constructed with the intention to serve more than a single purpose. The purpose served by these projects include, prevention of floods, irrigation for agriculture, generation of hydroelectricity, fish breeding, recreational purposes, inland water navigation, to provide water in deficit areas, and provide water for domestic and industrial use.

The above mentioned reasons clearly suggest that multi purpose river valley projects are very advantageous for our society and economy but the real picture is very different than that because the construction of these multi purpose river valley projects has multiple drawbacks as well. When the river water gets regulated and becomes stagnant due to the damming then it badly affects the natural flow of the river which further results in poor flow of sediments and immoderate sedimentation at the bottom of the reservoir, this severely affects the aquatic flora and fauna of the river. Rivers often get fragmented due to dams and it again severely affects the aquatic wildlife as they fail to migrate. The construction of reservoirs takes place on a floodplain, which is a very fertile land. Due to the construction reservoir, the entire floodplain gets submerged, such a waste of a very healthy and fertile land which could have been very well used for agriculture.

Hence, the correct answer is option (D).

Note:Hirakud dam in Odisha is considered the longest dam in India while Tehri dam in Uttarakhand is considered the highest dam in India. First dam to be constructed in India was Kallanai dam also known as Grand Anicut on river Kaveri in Tamil Nadu, it was built by king Karikala Chola of the Chola dynasty.