I've never seen where the water is coming out. It's probably going through the dam, which is covered in deep grass. When the level drops to a certain point, the seepage nearly stops. I don't know what depth still remains, but I'm guessing it's not more than a few feet. Neighbors who were around here when the pond was built said they've never seen it go dry. Being bullheaded, I will probably give bullheads a try, if I can get some.
