And flood the land upstream. If the dam breaks suddenly, then the large amount of water held behind the dam can flood the areas downstream too. Broken ice dams are not the only dam problems that can cause flooding. When a large human-made dam breaks or fails to hold the water collected behind it, the results can be devastating. Dams contain such huge amounts of water behind them that when sudden breaks occur, the destructive force of the water is like a great tidal wave. Unleashed dam waters can travel tens of kilometers, cover the ground in meters of mud and debris, and drown and crush everything and creature in their path.
Although scientists cannot always predict exactly when floods will occur, they do know a great deal about when floods are likely, or probably, going to occur. Deep snow, ice-covered rivers, and weak dams are all strong conditions for potential flooding. Hopefully, this knowledge of why floods happen can help us reduce the damage they cause.

1. What does saturated mean in the reading passage