I suspect that some bureaucrat coveted the property, either for themselves or for a crony or there is some personal pique against the Sacketts.
There is some rotten individual(s) behind this somewhere at the state level or below.
The way they determine this “wetlands” designation seems to be by flying over a given area and then designating lower elevation patches as “wetlands.” I looked at a property in Northeast Florida that was perfectly dry, in a moderately built-up area and far from any water but which had recently been designated as “wetlands” (thereby destroying its value) in a recently produced map.
I’m not sure it’s so much for the personal gain of the bureaucrat as for the ideological program of the EPA as a whole, which is that human beings are bad and human habitation is evil. Both the EPA and its ideological bent have become much stronger since the arrival of Obama, and if they could, they would declare the entire US unbuildable land.