During the British Rule Mettur Concrete dam, hydropower projects were built. But after independence India have about 1550 major hydropower dams and thousands of minor dams. The main objectives are as follows:-
- It helps in irrigation facilities.
- It helps in the generation of electricity.
- It helps in the flood control.
- It helps in Employment generation.
- Inland fisheries.
Advantages of Hydropower Projects:
Irrigation facility is available for 60 percent of the total land area. In 1950, irrigation facility was available to only 20 percent of the total land area. This increase was made possible by hydel projects. The food output has therefore, increased considerably.
The food output has increased almost four times the production level at the time of Independence. But this increase is due to many factors like increased irrigation facility, availability of fertilizers, pesticides, technical knowledge, hybrid high yielding seeds etc.
These dams regulate rivers and therefore, prevent floods. By regular floods there was heavy loss of resources like animal’s crops, man and their properties. The floods have been checked to a large extent because of these hydel dam projects. But some dams have been blocked due to heavy silation and their water storing capacity has decreased. This has created problems. Besides providing irrigation and checking floods, these hydel projects help in local transportation recreation, in land fisheries and in the process generate thousands of jobs.
In recent years there has been growing debate on the overall usefulness of constructing big dams.
Large hydel projects are ecologically disruptive, submerge cultivable and rich forest land destroy biodiversity cause soil erosion and siltation. Narmada valley project and Tehri Dam Project the construction of big hydel projects are opposed and brought National agitation.
- The dams have led to the destruction of natural resources like forests and wild animals.
- The big dams have destroyed the riverine system; farmers and fisherman in the downstream areas have lost their livelihood.
- The big dams have caused extensive water logging and in the process million of hectors of productive fend have become infertile.
- The big dams also cause earthquakes because the huge amount of standing water puts enormous pressure on land.
- Construction of big dams has changed the life style of the advises community and hilly people traditionally depended forests for their livelihood. The big dams destroyed their way of life.
- A huge amount of funds are utilized to construct the dams.
- Displaced people do adopt alternative means of livelihood.
- The environmental issues like soil erosion, silation, water logging, salinity, food occurrence and control, deforestation, and loss of habitat for wild life, earth quakes and Tsunami are involved.
- There is a health hazard of the people.