Flood zone effect?

One Minerva Place: a strong argument for summary execution of architechts

One Minerva Place, Old Greenwich, was built in 2001, and its last sale, to the present owner, occurred in 2006, when it sold for $3.850 million. It's been back on the market since 2015, when it started off at $4.295, a price that's been steadily reduced as the days and months and years go past. Today, it was marked down to $2.995.

While its exterior is butt-ugly, the house is pretty nice inside, so what gives? How can a house in Old Greenwich, in a great neighborhood, lose a million dollars in value in eleven years? My guess is that, because it's in the AE flood zone and was built in 2001, it no longer meets the minimum elevation requirements for that zone, so it's options for renovation and expansion are restricted, probably down to zero.

That may not be so; there may be other reasons for its failure to sell, but the flood zone restrictions seem to me to be the most likely explanation. If so, then thank Town Planner Katie Blankley, and you buyers out there, thank me: I warned you about this colossal loss of value imposed on Old Greenwich owners long ago. 

UPDATE: I'm informed that the house is flood zone compliant, which simply raise the original question: how can a house in this are drop $1 million from its 2006 price?