My thinking on usuing concrete in conjuction with the anti-seep collars is compaction and overkill.
My thought is to use 6 inch Sch 40 PVC for the line running through the dam. The sides of the pipe will act as a drain like Brettski mentioned, but the collars will displace that path. I understand how this works and I'm in agreeement on using them. Using a solid material over a flexible rubber is interesting, but I fail to see the advantage. The flexible rubber is slid over the pipe very tightly creating a water tight seal. Any solid material will rely on glue or a seal of some kind to stop the flow of water. To me, this is a weaker design.
Compaction around this area is a real issue that I'm worried about. No way to do it by hand anywhere close to what I can do with my tractors. I can get real close to it and work around it, but to really get a solid seal and maintain the maximum integrity of the dam, I'm thinking concret would work. It would be a soupy mix more for filling a void than for strength, so a little extra water in the mix wont matter.
When you say your anti seep collars are 48 sq inches, do you mean 48 inches by 48 inches? I was thinking of 24 inches by 24 inches for 576 square inches of surface area minus the six inch pipe going through the middle of it.
Another option that I've wondered about for stoping the flow of water along the drain pipe would be along the lines of creating a small solid seep colar of less than a sqare foot. Glue and silicone it into place, then pouring concrete all around it to totally encapsulate the entire collar.
Thank you for taking the time to help me with this,
Eddie
