Looks like I'm in the minority here.
Most ponds around here have stand pipes. If installed correctly & you have good clay soil there shouldn't be a problem. I checked around before I built my new dam for references & pond owners here don't even know what an antiseep collar is. I guess it's this red clay, it compacts like a rock.
My small pond had a stand pipe that rusted & fell. The pipe thru the dam clogged & the pond refilled. All this before I bought the place 19 years ago.
I used a siphon to drain the pond last year & it wasn't easy. After 3 tries with the sipnon stopping and then using a pump I finally got it drained & had to hurry to unstop the original pipe so it wouldn't refill. (There's a good spring feeding)
When I built the dam for my new pond I put in a drain pipe so I would never have to go through that again.
Just thought you ought to hear a different view.
Mike Otto had a piece in Pond Boss mag about pipes through dams.
