esshup,
Your pond example is a good puzzle to solve!
What do you think about trying to have nature do the work? If you see a big rain event coming on the radar that is going to muddy the pond anyway, would it work to deliberately stir up the muck and then let the water flow push some of the crap out of the pond? (Or is the muck generally too dense and will settle out only a foot away from where you stirred it up?)
I was thinking of putting your boat prop just above the muck line, or pulling a small drag harrow through the muck from the shoreline.
Hopefully, the storm water flow through would push some of the sinking muck through the bottom drain. If you liberated some floating muck, then you could add a siphon pulling from just below the surface.
If your fish excluder on either drain was immediately clogging, then could you remove it and build a settling pond with fish trap on the discharge end of your drain pipe?
[Obviously, this muck removal plan is only for a situation where it is permissible to pass "crap" downstream through your discharge pipe.]
I guess this might even work without the storm. Instead of trash pumping to the shore, you could put the pump discharge directly in your pond drain pipe. Open your drain valve and let 'er rip. Then all of your water erosive force would be going to an area designed to handle it, instead of onto a beautifully manicured shoreline.
