Thanks All for the tips and stories. We are going to drain the pond with pumps (if the leak doesn't do it for us). Requisition magnifying glasses and or microscopes to search for the cracks and fissures -- ie, study the rock bottom real hard. And then come up with a plan. It may be we go with packed and rolled clay on the bottom as a first attempt - we do have some close by that is good material. Or we may decide to go with the liner approach. It will be a tough call. If we go with the liner, I am thinking Reimforced polyethylene - the Pond Gard is just too dang expensive. If we go RPE, we will study burying it. I sure hope we can get it to work because I think it will be beautiful if we do. Pic attached
