sentences:  Rivers have been dammed in order to store water to generate electricity for countries’ economic growth, or for export to neighboring countries to generate foreign exchange earnings.Damming a river section transforms that section into a large pond, reduces the temperature and oxygen content, and increases river-bed erosion and water turbidity downriver.Reservoir operation procedures result in occasional or regular flooding of sandbars, sandbanks, stretches of channel mosaic, and other habitats that would normally be exposed during the dry season, with impacts on nesting bird and turtle species.