Design
The Way We Build Cities Is Making Them Flood
But the problem is not what you think.
It sounds like a pretty safe assumption that the people who live in flood plains, or own businesses there, face the highest chances of flooding. This was certainly true during Superstorm Sandy in low-lying coastal areas at the mercy of storm surges. And the Federal Emergency Management Agency calculates flood risk this way all over the country, plotting properties against the geography of flood plains.
And yet here is a map of the Chicago metropolitan area, its flood plains shown by squiggly blue lines: