ABSTRACT
Hydro power (which accounts for about 6 percent of worldwide energy use) is in itself a relatively cheap, renewable and non-polluting energy source. However the dams built to produce it present a number of serious environmental problems. The reservoirs for large dams are created by flooding vast swathes of land, often inundating valuable forest area, wildlife habitat or wetlands-often entire ecological communities. In warm climates, reservoirs can pose health hazards, increasing the incidence of waterborne disease, such as schistosomiasis, and ‘river blindness’. The quality of water from dams often deteriorates, due to a build-up of salts and chemicals, posing threate to irrigated crops and drinking water supplies.
