not having much experience with bogs or bog plants, the immediate idea that popped into my head was to go get some sort of Sterlite or rubbermaid container from a wally wonderland type place. The kind that is shallow and rectangular - the kind that is made to slide under beds.

Put that into the 3' x 2' area, backfill around it and between the pond and the exposed end of the container with rocks. I could be way off base here as what I'm picturing in my head from your description may be completely different from what the reality is. But, one thing is for sure, you wouldn't have to worry about mud washing out of the wall of a plastic container!! LOL

might put a terrace or a drain pipe around the pond that would dump the unwanted water in a safe place. By holding the outlet at an elevation to hold some water it could still be used as a bog. If you put in a pipe it would need to be sized large enough to carry the expected run off.

those are both really great ideas. i wonder if i can incorperate both of them.. that would be awsome. i could put like an overflow pipe in the container to run into the drain line around the pond. i love that idea. thanks a bunch for your sugestions. i'm going to take a pic tomarrow of the area so you all can see the area i'm talking about.