That's why we're taking action. Over thousands of years, dams have been created to manage flood waters, harness water as hydropower, and supply water to drink or to irrigate fields. At least 45,000 large dams have been built to meet an energy or water need. Nearly half of the world's rivers have at least one large dam. In the last fifty years, however, experts have discovered negative environmental and social impacts of dams.
Dams are the main reason one-fifth of the world's freshwater fish are now endangered or extinct.
Large dams are causing much destruction worldwide, fragmenting and transforming the world's rivers while displacing an estimated 40-80 million indigenous people. The numbers of indigenous people shrink as their ecosystems collapse, leading to an irreplaceable loss of culture and language, wisdom and medicinal plant knowledge.