I have an acquaintance here in SE Virginia that had a low lying marshy, wet area on his 25 acre property. He wanted to dig a pond, and thought that would be the ideal location. The water table around here is very high, often just a few inches below the surface, and many people have "water table only" ponds that stay pretty full all year.

He called the Army COE. They came out and looked at the site. They looked around and said that he could not build a pond, but they were going to take three acres of his property (including the marshy area) for a conservation easement. They gave him "market" price for the three acres. Now he has a three acre area in the middle of his property that is owned by the state. And no pond.....