A couple feet of water is still disastrous though. You're insurance most likely doesn't cover it and you could be left with tens of thousands of dollars worth of damage easily.
It really depends. In my neighborhood in Louisiana, most yards sloped down to the street. So when the flood was a couple of feet at its deepest, most houses were still fully above the waterline. It's just that the streets were impassable and you needed a boat to get around.
