I'm building my own personal pond at the moment. Well,trying to between working and the rain. Anyway I keep getting water under my liner and I'm worried about it putting to much pressure on the liner and tearing the bottom of the liner. I say this because the rock we use around here is pretty jagged and some what sharp for epdm liner. This is a new problem as I stated in another thread. If I run a pipe under the liner and exhaust above grade will the pressure force it out or will I need to pump it out since it will be going uphill?