Big Waterfall Spillway Liner
Once the area is stabilized, compacted, and shaped, the underliner is put in place. A 45 mil. EPDM rubber liner is placed on the spillway over a protective felt liner on the entire falls and styrofoam padding where the support walls are. This will lessen the chances of punctures rubbing. Rocks are then gently laid out to help shape and hold in place.
Also See: How To Build A Waterfall