Once drained and allowed to dry or freeze over the winter, can a dozer get in there and move the silt and muck allowing it to be hauled off? [/quote]

I think a dozer can get in there but how would I go about draining it? I would really hate to do that then I could posibly lose all the fish. I hasve also heard about possibly going too deep and then the pond won't hold water, but how is that when the pond held water all this time?
I have 3 sections that are approx a 1/2 acre each. I have figured out where I could dam it up and then drain it one section at a time. I would think to let it sit for several months so the silt can dry up some. But what type of dam could I build that would keep the water out of the drained area?