https://phys.org/news/2021-08-disaster.html?utm_medium=email&utm_source=rasa_io&PostID=35536873&MessageRunDetailID= [login to see]
Basically, the answer to the question is the amount of damage in dollars. The sad part of this is one of the things government is supposed to exist for: to stop people from building where they shouldn’t. These flood areas were identified a long time ago. Unfortunately, they made it a game with FEMA Flood Rate Maps that allow people to build where they shouldn’t as long as they have insurance. Does that sound right?