Lynyrd, just a few thoughts on the brush in the creek.
Running water is always fastest 1" below the surface. If you have large tree tops in a pile, then you can bet the water runs pretty fast through that creek. If there is enough current, then non-floating trees/logs will tumble until the water flow slows down enough to let them naturally sink and overcome the current. This creates log jambs, and I bet that's what you're seeing.
As much as I like junk in my pond, I would be very leery of leaving that brush pile in the creek. I've had the best results adding cover at the 1-6' depth. If enough water does come in to breach that log jamb, then the limbs may float and become an issue. Or, they may sink to a depth that doesn't help the fish anyway, and they'll just be rotting wood sitting on the bottom of the pond. Either scenario boils down to a game of chance, and removing the trees eliminates that.
