Just FYI:

The "flood plane or zones" come from the 100 Year Flood surveys done by the Gov't. A home is either in or out of those boundaries outlined in those surveys. Sometimes it's just a little piece of the property, sometimes (although rarely) it's the whole thing.

Since those zones are not updated very often, it is possible to argue that your property no longer lies in that zone by getting (and paying yourself) a topographical survey done. It is not cheap by any means, but if you have to have flood insurance you also know that's not cheap either.

Ultimately it is up to the mortgage holder as to what they feel comfortable with. Some will change their minds while others won't. Every mortgage requires a flood certification to be done PRIOR to final approval for this reason. That cert. comes from the insurance companies study of those 100 yr. flood maps.