Thanks Ken for posting those pics. I guess I'll work on that skill next.

The pipe is around 12" in diameter, need to measure to be exact. Plugging the intake is a good thought but here are my issues with this....first, it is approx 13 feet under the water and I have never even seen it. Secondly, if I plugged the intake then I would not be able to use the valve allowing me to drain the pond to a lower level when desired, ie. during winter to kill moss around banks, working on any issues with dam, future dock building projects, etc. And lastly and most importantly, I saw a snake in the water last week and I don't go anywhere snakes might go. But I agree, plugging the intake would probably be easier.

[Linked Image from i108.photobucket.com]