Flood Facts



  • A flood is when a river or the sea rises so much that it spills over the surrounding land.
  • River floods may occur after a period of prolonged heavy rain or after snow melts in spring.
  • Small floods are common; big floods are rare. So flood size is described in terms of frequency.
  • A two-year flood is a smallish flood that is likely to occur every two years. A 100-year flood is a big flood that is likely to occur once a century.
  • A flash flood occurs when a small stream changes to a raging torrent after heavy rain during a dry spell.
  • The 1993 flood on the Mississippi–Missouri caused damage of $15,000 million and made 75,000 homeless, despite massive flood control works in the 1930s.
  • The Hwang Ho river is called `China’s sorrow’ because its floods are so devastating.
  • Not all floods are bad. Before the Aswan Dam was built, Egyptian farmers relied on the yearly flooding of the River Nile to enrich the soil.
  • After the Netherlands was badly flooded by a North Sea surge in 1953, the Dutch embarked on the Delta project, one of the biggest flood control schemes in history.
  • Even when no one drowns, a flood can destroy homes and wash away soil from farmland, leaving it barren.