A 100-year flood is a flood event that has a 1%, or 1 in 100 chance of occurring in any given year. It does not mean that it will occur once every 100 years.

A 500-year flood is a flood that has a 0.2% chance of occurring in any given year. It does not mean that it will occur once every 500 years.

The clock for floods resets each year. Just because there was a 50 year flood event in 2009 does not mean that a flood that large or larger can’t happen for another 50 years. There is still a 2% chance of having a flood that large or larger any following year. This applies to all flood events (10-year, 50-year, 100-year and 500-year events).

Slide to see conditions before and after the project.

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