Pond Boss Forums Thread Like Summary - Concrete pond construction

Hello fellow pond enthusiasts,

I'm in the process of constructing a pond and would love to get some advice from those with experience in concrete pond construction. The pond has been excavated, revealing a sloping bedrock at the bottom. The sides are steep, almost vertical, and part of the pond structure is above ground, reinforced externally with a thick layer of soil and stone.

I plan to use concrete blocks for the sides, but I want to maintain the natural slope of the bedrock. To do this, I'll need to create a level base or foundation around the sides on the bedrock before setting the blocks. What would be the best approach for building the foundation? Could a circular slab reinforced with rebar work? What would be the best waterproofing agent or coating to apply to the concrete to prevent water leakage and protect aquatic life from the alkali content of the cement?

I'm aiming for a durable and eco-friendly solution that ensures the health of the pond's ecosystem. Any tips, product recommendations, or construction techniques would be greatly appreciated. I know that it would be easier to just use a pond liner but I am optíng not to.

Look at how they make in-ground swimming pools.

If it was mine, I'd not worry about using the bedrock to be the bottom of the pond, I'd shotcrete the whole thing. I would first plan on somehow putting a drain in the bottom so you can drain it out. to clean it. With no dirt on the sides, and no dirt on the bottom, what you are describing is more like an aquarium. With those steep sides, the fish may not have any place to spawn. Without dirt in the bottom, you will have a hard time getting enough plants and bacteria in the pond to deal with fish waste.

So some type of filtration system may be needed.

If you only shotcrete the soil on the sides, how will you ensure that it is sealed to the bedrock so water doesn't leak out between the shotcrete and the bedrock? There will need to be a sire mesh/rebar structure built on the sides to give support to the shotcrete so it stays in place while it is still wet. Again. similar to how they build in-ground swimming pools.

What happens if the bedrock DOES leak? What's plan B to address that problem?