There is a local quarry that can deliver river rock by dump truck. I estimate I need 10-15 tons of river rock for my pond. If they deliver it, can I have them dump it directly on top of the pond liner or is that likely to damage it? Note they aren't going to dump carefully, they just backup, tip the bed, and drop off 10 tons at a time. If they have to dump on the lawn nearby the pond instead, I think it would take 3-4 days of shoveling the gravel to move it to the pond.