cmanjim, i have the exact same situation. i made a rip rap (rock almost 1/2 the size of bowling balls) barrier across the upper end of my pond. i think it really helps with the sediment. i get a huge amount of water in my pond during a heavy rain, with the barrier i can see muddy water above it but mainly clear below.
The wood dam may be a quick and easy way to do that, and a good blockade too. It wouldnt wash away like rocks in high water either and mey make for easy cleaning when the sediment levels get high in the holding pool. I like scotts method too, and with your wood wall, I would suggest gravel or rock on the other side, to help with erosion and it does act like a filter.
Does the whole creek come into your dam or can you devert it when needed??
Crayfish make great Forage, post some picks and lets see what type they are.
Do you have trout in your dam now or trout in the creek??
