I have used pond muck (or sludge) to fill in low areas on my property and even made the backside of the dam twice as wide as it was prior to de-mucking. It took the muck a full year to dry up enough to be able to work with it. Otherwise is was like pudding. I would not use it as shoreline where it would come into contact with the water. I don't think it would dry at all and would remain much like quick sand and sluff back into the pond. The muck I had pushed to the back side of my dam sluffed off over night during renovation and about a truck load moved 25 feet and had to be dug back up and moved. It was fine and right where we wanted it when I went to bed, but the next morning it had flowed like lava and was not were I wanted it.

I had much of the muck corn-rowed in an adjacent field were it dried for most of a year and then I was able to scoop it up and put it in low spots in my yard. Some smoothing with the tractor blade, hand raking and grass seed...and it is the greenest parts of the yard.

You can certainly reach out and drag the muck out of the pond and gain some deeper shoreline waters, but I don't think it wise to use it at the shoreline unless more clay-like material is brought in to actually be the shoreline. The muck could be used to fill in between the new shoreline clayish berm and the surrounding yard...but it would still need to dry out before it could be handled.

Welcome to the forums!

Fish on!,
Noel