No real preps. If your house floods you leave.

But.. know routes and alternates to travel.
Know what areas will flood. Know how to get around when the lower levels go.

My house was up on stilts/piers about 3 feet. We had time but eventually it was flooded out. My sister's books were ruined.
We were able to return. My mothers sewing machine went to the repair guy and he placed the whole thing in a vat of kerosene he had waiting- he healed it.

Now, if you live in a flood zone, you should either be up on piers or have the garage and storage on the first floor and live above. Flooding is no joke.