My heart goes out to you. I hate to admit it but I live in fear of leaks. Particularly around the waterfall. Pipes are easy unless they are buried. But the waterfall can be tricky. Still, if you fully encased the entire affair with liner brought up high enough to catch splash and wind surges, then the only possibility for a leak is a hole in that liner, right? I know it's a super pain, but if you bypass and then see no leak, like Dr. Case says you've isolated it. you could then look at the rebuild as an opportunity to improve the look, etc.
Couple small things. One is to check if the liner has pulled away from the spillway in any spot. I'm sure you know to leave enough slack so any settling won't cause this. Two is to add extra layers of scrap liner under the rocks and other materials in the waterfall. you probably did that though.
Couple small things. One is to check if the liner has pulled away from the spillway in any spot. I'm sure you know to leave enough slack so any settling won't cause this. Two is to add extra layers of scrap liner under the rocks and other materials in the waterfall. you probably did that though.