I'm currently considering doing a waterfall that will spill into a swimming pool. I've built lots of ponds, but only one swimming pool application and that was 10 years ago. I remember being perplexed about something. I used an EPDM liner and had trouble with how to seal the liner to the pool lip (coping) so that any water from the water course didn't find it's way under the liner. Do I need to seal the liner to the pool lip with an adhesive and make sure it is cut close so that it doesn't show when folks are looking at the lowest rock just above the water level of the pond ? I plan on letting the rock overhang by several inches and that should help to disquise the liner below. Also, I plan on doing a good job of mortaring the water course so that very little water finds it's way to the liner underneath the rock. Am I on the right track? Has anyone tried doing something different? I don't want to rely totally on mortaring of the water course to keep water off the liner (cracks and crevices are eventually going to allow some water to find it's way below at some point) and I have had situations where water will "crawl" under a rock that serves as the last rock before the water spills into the main reservoir (or pool, in this case) and then eventually under the liner, which would not be good. Thanks!!