I had that done with one of my ponds a few years ago. I believe the term in the business is "dipping." My pond is about .62 acres. However the contract insisted on dropping the water level a few feet to see what he was doing. That was quite simple with a couple of pumps (one gas powered pump pumped 200 gpms).

Anyway he has a massive backhoe/excavator and just went around the pond reaching out as far as he could deepening it and making the banks steeper. It really muddied the water temporarily but did not hurt the fish.

He said we would have to allow the clay that had been scooped up and out to dry out and we waited until next spring. Surprisingly even with heavy rain it did not run back in. We then moved the excavated clay with a bulldozer and reseeded.

Cost was, I believe, $1000.00, but I had two other ponds dug so I'm not sure as everything was added together.

If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.