Track hoes are like loader tractors, just really handy. You just might end up using it a for more than you think.
Loading on a truck would probably work better than a scraper. The trucks can dump out the back and leave larger piles. The scraper scatters it as it dumps and then can't drive there again without getting stuck. So getting rid of the mud with trucks takes a lot less area.
If there is room behind the pond dam I have done this and it worked well, works best before the mud drys; Get rid of the water. Dig a nice place to sit the track hoe on the dam, where you can easily reach the pond on one side and reach over the back of the dam when you turn 180 degrees. Dig a sump hole on the pond side and throw it over the back of the dam. A lot of mud will actually run into the hole, just keep throwing it over the back of the dam. Use the dozer and start crowding the mud to the hole- the mud runs downhill pretty easy. Runny mud will also keep sliding down the backside of the dam if there is room.
