Today, the world's rivers are dotted with more than 45,000 large
dams-dams higher than 15 meters or impounding more than three
million cubic meters of water (WCD 2000).
Dams provide unquestionable benefits-from water supply to power
generation - but they disrupt the hydrological cycle profoundly,
suppressing natural flood cycles, disconnecting rivers from their
wetlands and floodplains, disrupting fish migrations, and altering
the deposition of sediments downstream.
More information: River fragmentation
