I'm going to the experts here for some advice. I've posted before under a different user name and got some great help from Cecil. It's good to be back and thanks in advance to everyone for your help.

Here's the situation: Four acre pond in NE Indiana was dug about 50 years ago on an old bog/swamp. The dozer operator uncovered a mastadon skeleton when it was dug if that helps tell you what kind of bottom we're dealing with. Story goes that the ground was so unstable the dozer operator quit digging because he thought he was going to sink his dozer and never get it out. As a result, the pond was only dug to a max of eight feet at one end and about three feet at the other. Probably averages 4-5 feet in between - muck bottom of course and add 50 years of sediment to that.

Pond is aerated (inedaquately) and has always been a good fishery. It has also always been choked with weeds - particularly coontail. Grass carp were introduced and added until we experienced the other extreme - all vegetation eliminated. Planktonic algae blooms like crazy created murky water and the LMB really suffered. Long story short - rotenoned the entire pond two years ago and started over. Pond is restocked but now has a serious filamentous algae problem. There are 25 grass carp in the pond but I can't tell if they are controlling the weeds because the FA is so thick.

I know the issue is nutrient rich water creating the algae problem and lack of depth creating the weed problem. Seems like deepening and removing sediment could solve those issues. Here are my questions:

Is there a solid bottom under there somewhere? I don't know how deep swamps/bogs go. I wouldn't want to start digging only to find that there's no clay until we're 40 feet down.

What's the best option for sediment removal? The "new" hydraulic suction method, mechanical dredging, or draining and excavating?

Looking forward to hearing your thoughts on this one.