Flood insurance is only available through the federal government. I stand to be corrected but it was kind of a racket back in the day to get flooded, rebuilt a much bigger and nicer home, get flooded again and do the same.The problem with a flood damaged home, is that if it happened once, it's pretty likely to happen again. And insurance companies won't cover some flood-prone areas.
Now, if I remember right, they rebuild one time and then the cost of federal flood insurance goes up by a good amount. If it floods again, the cost again goes up. I'm not sure when it reaches the point of "it's not worth it any more".
We have some folks in the insurance industry on here. Hopefully one will kick in with some facts.