It's likely you can still build within a 100 yr flood plain, you'll just need to have an elevation survey done to determine BFE (Base Flood Elevation), with your LFE (Lowest Floor Elevation) of your home and other buildings having to be at least one foot above BFE (so having a basement or walkout would likely be out of the question unless you bring in a LOT of dirt!). You'll then need to have a LOMA (Letter Of Map Amendment) or LOMR (Letter Of Map Revision) done to prove to your mortgage company your home is NOT in a flood plain. This will prevent you from being required to carry flood insurance.
There are other requirements as well, but as far as I know it can still be done (this could all be completely different in TN). Just be sure and do your homework first!
There's also a possibility that a pond/retention pond of some sort (here's where I'm very ignorant) could remove a portion of your property from the 100 year flood plain?
There are Flood Maps available through https://msc.fema.gov/portal/search
. You might also visit with your state's Department of Natural Resources for additional information. Or if you can find an insurance agent who's well versed in flood insurance, they may be able to help as well.
Here's an example of a flood map of my place: http://arcg.is/1LfOWIJ
where you can see the NW portion of my pond is in the Flood Way, and the remaining portion is in the 100 yr flood plain.