I hadn't thought about taping a drill to a board; good idea Esshup. I had thought before, that if I was going to drill it I would put clean rock under it. I don't know if it would drain without the rock, but it sure is worth a try. If it doesn't drain, nothing would be lost.
I put 14 unopen bags of sakcrete on the side that would feel the pressure during a siphon event. It's rained over 3" in the last few days, so I would hate to dig it out.
