I only use my dozer for clearing brush. I have never undertaken any serious dirt work projects with it. A good friend of mine has a pond on his ranch that the dam broke during a heavy rain last year. They have not had any rain since then and it is bone dry. I measured the pond on google earth and it is 1.25 acres. He remembers this pond being built when he was kid nearly 40 years ago. Nothing has been done to it since then. It has a lot of silt in it that has washed in over the years and he wants that cleaned out as well as the dam repaired. He doesn't know for sure how much is in there but estimates as much as 5 feet. He is going to pay to have the work done but he wants me to do it instead of hiring someone he doesn't know. He wants a rough estimate on how long it will take. Not doing dirt work on a regular basis I have no idea. If the silt is 5' that works out to about 10,000 yards. Any ideas? I know it is impossible to know without seeing it but I have no clue. The dirt that comes out doesn't have to go anywhere special. It can just be pushed out wherever is most convenient and this is just a cattle ranch it doesn't have to be super pretty when done just functional.
With all the youtube videos of stuck dozers, get out to pond and probe around. There may be 5 feet of silt or 2 feet of crust and 13 feet of shoe sucking mud.
If their is a decent bottom to it, one can get in with an excavator and cut channels to give the water in there a place to go and run out. Did one a number of years ago that was similar to what you are talking bout, washed out dam, silted in. Was able to take the excavator and just work through the silt digging trenches for the water to drain, then was able to get in there a few weeks later with the dozers and push it out. The dam was blown out as well and that needed a full rebuild, engineered specs and a new pipe system installed. Biggest thing if you are doing it on your own, make sure you get good material into the dam itself and compact. Good luck.
What size is your dozer? I'm assuming from the OP that it the pond was not created by damming up a creek and is only fed by rain water run off. If this is correct, then there is a good chance with a little luck that it can be all done with a dozer. As been said above, use good dirt to fix the whole in the dam and make sure you core it out good before you start filling the whole.