Well, every year I have to worry about my warehouse being blown down, but I'm not too concerned about the water. I'm on high ground, but I used to live down there in the muck. The wind always had me more worried than the water.
If the house can withstand the wind associated with flooding, and if it's built properly elevated, you can enjoy living there even with frequent floods. It happens all the time to some people, and it doesn't bother them.
You will, of course, have to be able to deal with the inconvenience of being flooded in (or out) and everything that entails, such as using a generator and making sure you're not out stocking up on French toast ingredients just before a storm.
Developments of such elevated houses are going up right now nearby. People have a handle on how to build the things now. They hold up very well. Generally, there is no garage beyond the space under the structure.
Sometimes a steel garage holds up, and sometimes it doesn't.
Is it ill-advised to live in a flood-prone area? Well, sure. It's a pain in the ***, at times. It can also make life interesting. If your house is going to hold up one way or another, though, and if it's not going to get wet, there's a lot less to worry about.
Floods are nasty. I've been through some serious examples, and I've lived in flood plains, but so have many others. Doesn't stop those stilts from being put up, though, and it doesn't stop the parties, or just moving your cars to higher ground before the waters peak.
You need to be walking in with enough cash to build that house to take the water, though, and very carefully determine just how isolated you'll be if a big flood does happen. Not everyone is capable of living like that.
As noted, get a secondary, precision survey. It may lower required expenses, and at the very least will give you a good indicator of what's going on. Moreover, you will be able to have a nice, long chat with someone who knows every inch of water that's risen in the area.
Rain-related floods can only rise so high. They'll fill a basin, and then start to peter out over a wider area. It's not as if it's going to be ten feet higher next year. Those "500 year" floods in the Southeast are about as big as you're going to see without incredibly unlikely factors. A week of saturating rain, a storm surge, the hurricane... Then it comes around again to hit a second time...
That's about as much water as you can dump somewhere before it just starts running off faster than it rises.
Now, in the West and North? Things can be different. Flood states can be tied to other causes that have nothing to do with your own area. They're not as predictable, and the peak levels may not have been reached in recent memory.
I don't know about that stuff; I'm only familiar with flash floods in desert regions and the Southeast hurricane floods.
