Hey guys. This thread is very timely for me. I have been lurking for some time and have read just about every thread on the site...literally. I think I will be looking at a similar situation with my pond (hope to go 120' x 80'). The soil is sandy loam with MANY large rocks and boulders, most of which are actually in a boulder field several feet thick. While I am going to get a backhoe to test several areas for clay, I believe a liner is my only option and hope to cover it with the boulders. Two applicable questions....
1 - What type of machine can you run over the liner once it is down (if any) and/or
2 - Do you have to cover the liner with soil over the entire surface area and then put boulders over top or could I just place boulders over the liner?

Any help you can provide would be much appreciated. I am working on a formal presentation to be given to Victoria to build this pond and I want to make sure I have answers for questions that may arise.