For the umpteenth time we re-did our pond waterfall. Well, maybe it was four times that we re-thought that waterfall. Each time having to remove bolder after bolder out of the way - very heavy stuff and back breaking work. You see, we kept losing water and couldn't figure out why. Finally I did some serious research. The first three times we "fixed" the waterfall never did we realize the liner was key. We had used the liner for the actual pond section only. We had constructed the waterfall out of three flat pieces of flagstone built in a stair step fashion. We piled rocks all along the sides all the way down the waterfall. Each time we made sure the water was being directed onto the stone pieces and no water was splashing out. Well, I guess that wasn't right. Somehow, even though the flat rocks were pointed downwards and water was flowing into the pond, we were still losing water.
After seeing several pond layouts online, a really good site had all the waterfalls being constructed on top of the liner. Not a separate liner, but the same liner that the pond was built around. We remembered we had rolled the extra liner up when we built the pond. So when we removed all the bolders again and unrolled the liner, we had plenty of length left to place under our waterfall. We then proceeded to replace the bolders this time on top of the liner then rolling the extra liner up on the outsides of the bolders, and low and behold we have not lost any water!
Hopefully this will be the last time we have to build our waterfall....