Hydroelectric dams are said to be one of the cleanest and cheapest sources of renewable energy around. They produce no direct waste of their own, and carbon emission rates are considerably low, especially when compared to fossil fuel powered energy plants.
However, hydro dams cannot be considered "green" source of energy, since they tend to have enourmous impacts on local biodiversity, give way to degraded environments, influence geological changes and severely impact local populations.
For instance, an estimated 40–80 million people have already been forcibly evicted from their lands to make way for dams. "These people have often been left economically, culturally and psychologically devastated," says International Rivers (IR), an NGO that pays special attention to hydro schemes around the world.
"In addition to huge social and environmental impacts," IR continues, "dams often fail to meet projected benefits. In November 2000, the World Commission on Dams (WCD) released a highly critical report showing that dams have on the whole generated less power, irrigated less land and supplied less drinking water than projected, while costing significantly more than expected. While dams can prevent some floods from occurring, the WCD found that they can also worsen damages suffered when floods do occur. Better options for meeting energy, water and flood management needs exist."
At the same time, there is a considerable amount of mythology surrounding the actual purpose of hydro dams, whether it's the Belo Monte dam in Brazil or the Tipaimukh Hydro Electric Project in Manipur. Industry professionals and governments often say the new dam would bring much-needed electricity to local city centres and support a growing population. However, in most cases, the electricity is really intended for industrial projects like new mines, and to support populations in other countries.Supporting other countries isn't so bad, but governments aren't upfront about it, because they would face a great deal more criticism and condemnation from the populace.
Whatever the actual benefits of hydro dams are, they don't outweigh the consequences; that is, the enormous burden thrust on to the environment and especially local populations like Indigenous Peoples. It is therefor imperative to speak out against hydro dams and pressure governments to explore better options.