Here's what we did when we installed our bog and pond 2 years ago. We are on a slight slope, so the top most pit is the bog, which drops in to a middle pond, which drops in to a lower pond. Disregard the black plastic edging ... we are phasing that out little by little.
Here is the underneath parts. Cinder blocks, filled with clay and pounded with rebar.
Here, we've added capstones, which we fastened to the cinder blocks with construction adhesive. We covered all the sharp edges with bubble wrap and duct taped it down.
Another view. The lower channel in the middle of the cinderblocks is where the bulk of our waterfall comes down.
We covered all of this with 1 continuous liner. We also covered the edges with Rock On a Roll (note that we have since taken all the RoaR out and are redoing our edges.
For the part of the wall below the waterfall, there was exposed liner above the waterline. Rock on a Roll to the rescue. Still need to clean up the funky corner, but you get the idea:
Does this help at all?
