Water facts: The big picture

Supply Use Crisis areas Health Dams
Click on the tabs above for a statistical view of the world's water

The Hoover Dam on the Colorado river - there are 45,000 big dams in the world, nearly half are in China and more than 6,000 are in the US
Last century saw a dam-building boom - but the pace has slowed as many doubt that the benefits outweigh the human and environmental costs.