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Impact of Dams
Dams are a source of water storage and conservation. However, there are
controversies regarding the scale of such dams, large, medium or minor, which
need to be constructed keeping in view of its societal and environmental
impact. With over 5000 minor, medium and major dams already operational,
both positive and negative impacts have been observed from their construction,
operation and maintenance.
Positive Impact
By and large Indian agriculture has been a major beneficiary of dams on all
scales. Estimates indicate that the large and medium dams have
contributed to approximately 25 per cent increase in agricultural production.
Minor dams scattered throughout the country have contributed to 15 per cent
increase in agricultural production.
Multipurpose river valley projects have also contributed to about 20 per cent
power generation in the country, besides flood control, recreation and
water supply for domestic and industrial needs.
Negative Impacts
Disruption ands displacement of affected communities
Large dams on an average affects about a million people, having
tremendous upheaval in the lives, mostly tribal. In addition live stocks are
affected, agricultural lands are submerged and lost, affect the existing heritage
structure by submergence, spread of disease.
Disturbance of ecosystems and loss of biodiversity
This includes :
Loss of forests and wild life habitat, loss or endangering of flora species,
disturbance of aquatic and riparian life, changes in the river morphology and
quality of water and changes in the groundwater regime.
