After experiencing two flash floods in two years, I'm considering investing ~$2000 into modifying my yard's terrain, and building retaining walls, to keep flooding away from the home and vehicles, at least for waters reaching ~2 ft depths.
I saw on the news that some entire towns were horrifically destroyed by flash floods, with both cars and people being swept away.
My concern is, if I invest in protecting my house in this way, what happens to the value of the home if it survives, but the neighborhood does not? Do communities hit by serious disasters usually rebuild or relocate?
I see in the news cases of tornadoes removing parts of neighborhoods, but not all. In that kind of situation, what typically happens to the home value of homes that survived but are left surrounded by ruins?