This particular project was a custom remodel. There was an existing rock structure and massive koi pond. We demo'd out the pond and created a swimming pool. Our artificial rock contractor elaborated on the existing structure. This was not your average waterfall. For a frame a reference, a 5' high x 10' wide real rock waterfall using our most expensive rock type would be around $10,725. A 3' high x 4' wide would be about half that.