Even that is a little misleading (given how bad our intuition about statistics is). A '100 year flood' is flood that has a 1% chance of occurring in any given year (it's independent of what happened 1, 5, or 50 years ago).
Calling it a '100 year flood' makes people think 'oh, good, now we shouldn't have one of those for another ~100 years'. In reality, the odds of a flood of the same magnitude occurring next year are exactly the same as they were this year.
