Crazy,
If it weren't for crazy ideas, then I probably wouldn't have any ideas
Try going to the search function and entering "pond dam piping" under a keyword search (make sure you use the quotes).
This will direct you to lots of threads that discuss a siphon drain system. This may be a perfect application for your pond. The siphon drain allows you to drain the pond when needed. It also allows you to pull off the bad "bottom water" as rains add some water to your pond level. Finally, changing the siphon level will also allow you control of the surface level of your pond.
Draining the pond water from the bottom will also help alleviate the debris problem you encounter in a forest pond. (You will have to be careful to keep leaves out of the siphon, but that is an easier problem.)
Best wishes - Rod
