This is what I call our "drain box" - because I don't know if it has another name.
It's about 10'x12' and runs down to the base of the dam (as near as we can tell). Inside it is a corrugated steel pipe that is about 30" (I'm guessing) in diameter that runs through the dam and dumps into the creek on the other side.
Anyway, it's a kind of a "standpipe" arrangement only the concrete box is the standpipe. I've never seen another one like it.
What's it called? What are the potential issues with it? Keep in mind that we are in the all-hard-red-clay-everywhere-for-100- miles area. Ponds around here almost never leak.
