Jeff, what you have shown in the diagram is a drop structure. A stand pipe riser is located on the back side of the dam and it's height is equal to the height of the pond and pool level. From your description of water shed I would not think you need a very big pipe for the over flow. A 6 inch pipe is much cheaper than a 12 inch when using pvc. A 4 inch is even cheaper. Unless you really think you'll drain down the pond often the most economic method would be to just run a pipe straight thru the dam sloping from pool elevation to the ground level at the back of the dam toe. Good Luck.

Last edited by rockytopper; 07/09/08 12:30 PM.

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