Thanks for all the replies, guys! Let me start this story over.......
A "friend of a friend" owns the land and built both the marsh dike and a small fishing pond some years ago (~10 years). The marsh and pond have always had water loss problems and neither have held water in the last few years. The landowner lost interest in the project and no longer waterfowl hunts. He did try bentonite patch before, but I don't know any details beyond that (other than it didn't work).
There are numerous shallow water impoundments that are seasonally flooded for waterfowl in this area, so I'm hopeful this problem can be solved.
What/where should I start?
1. identify soil composition
2. get NRCS involved
3. have a local heavy equipment expert review the situation
4. find out who and how the dike was originally built
5. ???
Thanks again for the knowledge!
