Can anyone tell me if there’s anything I can add to my pond bottom take make it harder? It’s currently just muck that you sink 6-12” into with every step (see attached pic). The pond builder packed a 2” solid layer on bentonite down, then packed 12” of native soil (consistency of powder) on top of the bentonite. So far, the pond edge, submerged and not, has claimed a boot and a croc, the crock still in the mud beneath the water. Would adding gravel, or pea gravel, to it compromise the bentonite layer if it just sinks through the mud, or…. ?
I think there is zero concern about any gravel placement sinking through and rupturing your bentonite "seal". However, I don't think gravel on "boot sucking" material would help much, unless spread on a fabric barrier and emplaced pretty thickly.
WHY do you need to walk on the damp clay? In a pond with very shallow slopes on the shore line, the clay ten feet outside of the water's edge is probably still going to stay damp in a slowly subsiding pond. During summer, you might get a sun-baked crust on top, but you can still break through that until it gets pretty thick.
If you need access for fishing, perhaps set up some "fishing stations"? Set these up where you (or a kid) can cast to your fish attractor structure.
You could build little "mini docks", drag in tree trunks, or lay out quality ground fabric and cover with gravel to make "finger" walkways into the pond.
Do you own any earth moving equipment? If so, you could build little peninsulas out into the pond 1-2 foot above the slope. (Might need gravel on the slopes and the deeper part of the top that would be underwater at normal pool so wave action does not erode your peninsulas.)
I think one good "poor boy" solution would be to get fabric and the largest surface area pavers available at your local big box hardware store. (Like the cheapest 16x24" pavers.) Install those side-by-side on fabric as far into the pond as you like. A grown man walking with one foot on each paver should barely sink them at all. The deeper ones will get covered with a little silt when your pond level goes up, but you could still easily walk on them when they are underwater a few inches with your muck boots. (They might get slippery though.)
Just throwing out some ideas, to see if any might help you for the actual situation you are observing at your pond.
I don't know if it would compromise the Bentonite layer (I ignorantly doubt it would), but you would have to add quite a bit of gravel to 6" - 12" of soft muck to firm it up. Last winter I ran the cows through a 16' strip they had never walked on before, which quickly created 4" - 6" of soft muck where turf had been. I had to add roughly 1/3 that thickness of gravel to the area to firm it up. I think under water (where it ain't gonna dry any) would probably be worse, and if there is any inflow of silt to the pond, could be an ongoing process.
It might be feasible for a limited area like a beach.
FishinRod I think those are good ideas. If he wants a swimming beach entry area he could allow the pond to drain down 3-4 ft and install a cement beach as wide as a car or truck hood out toward deeper water. Basically a wide cement sidewalk. Then when the pond fills the entry area would be all cement based. There are a few ponds near me including mine that have various designs or versions of a cement beach.
