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
If you are going to see the rise in pond level anywhere near where you estimate, you can use that height gain x surface area for a rough estimate of the amount of water that went in and divide it by the time consumed to make it happen.
Don't forget to carry the bum.