I own a Bucyrus Erie 22B and dug a good deal of my pond with water in it using the dragline. It will be a muddy, messy ordeal and to handle the material generated digging two acres while under water. Add to that you will need a 2 to 4 acre spoil area to dump the material and a truck that dumps nearly vertical because mud sticks in the bed when you try to dump it. Personally I believe in drain, dig, refill, restock, etc. There are companys that can dredge it, but it would not be a cheaper avenue to a nice pond. I would guess the mud will kill your fish. Probably not what you wanted to hear but rather a few things you should know.
