When I had my pond cleaned out and rebuilt last year, my contractor came in with a tract hoe and cut the dam. He let it drain and dry for a week, then came back in with the dozer and track hoe. They dug all the muck out with the track hoe and used the dozer to spread it out and mix with all the rest of the dirt. They didn't take the dozer into the main part for at least 15 days after the dam was cut, and then only after most of the muck was removed with the track hoe. Hope this helps...
