When I built my lined ponds I had to hold down one seam with standard 8 X 8 X 16 concrete blocks with the two holes in them. When the pond was filled I went into the pond with scuba equipment and found all of the largest bluegill backed into the holes. One bluegill to a hole. It seemed to me that this corrugated drain tile, if I'm using the correct term, would be an inexpensive way to concentrate the best bluegill in an area that was nearby the small dock being built.
