I think you should absolutely do it.
I would use the red pipe diagram and extend the pipe further into the pond, close to the bottom, if you can.
They pretty much finished the pond yesterday--just before the rains came. All that is left is the ditch project. The contractor wanted to have the entrance at the bottom of the ditch, and I wanted it at the top (so water would never flow backwards from the pond). I came up with a compromise that will let him put it at the bottom, but do it so that I could come along later and add an elbow at the entrance to raise its level. The project is going to be about $1000 for the digging and about $1000 for the 270 feet of 10" pipe he wants to use. We'll put some rip rap to deflect the flow at the outlet. With a three foot head and a 10" pipe, I expect the flow to be in the range of 1300 gal/min when the ditch is full. That's a lot of water, and it would raise the level of the pond by about 3 inches per hour. I'll post pictures when we start. Thanks to all for the suggestions.
I wish I could figure a good way to measure the actual flow. Any ideas? I thought about burying an old horse water trough at the exit of the pipe, but that seems like too much trouble.
Charles
