Jeffrey,
Clicking on your links I only see the Google account sign in screen. A picture would help (“It has a bottom draw with an up pipe on the back side of the dike even with the water line. It also has a drain valve.”) to explain this to those reading your thread. The way I understand it is that your 3” overflow pipe runs through the bottom of the dam inside the pond and outside the back of the dam. From this point there is an upside down 90 degree T with the drain on the horizontal side of T furthest from the dam and a piece of 3” pipe sticking straight up in the air on the upside down vertical T on the backside of the dam. The height of the 3” pipe is 4 inches shy of being level with your emergency spillway when the pond is full. If this is correct what is the source of water for the pond (runoff, spring or stream fed). Do you know the size of your watershed or gallons per minute if it is spring or stream fed?
Heppy
