A 100-year flood, like a 100-year storm, is one so severe it has only a 1% chance of hitting in any given year.
Unfortunately, many people believe that if they experienced a 100-year flood this year, they will not see another one like it for 99 years.
It just doesn’t work that way. In reality, the chance of being flooded next year, and the year after that, is the same as it was when the house flooded the first time – 1%
Read more from Robert Mace, Executive Director of the Meadows Center for Water and Environment, here.