If your brush piles and logs are going to be that deep, you also need to know that some of that will be below the thermal-cline and will not decay as fast due to the lack of O2 down there. Also, the fish will not live in water without O2. I think the minimum is around 3ML. Below that, the water will not support most fish life, so few if any fish would use that area as cover. There are other things to think about as well with deeper water, sunlight, and temps are just a few. Of course, aeration could change that if you are planning on aerating.

In short, there is a lot more to think about besides just where to put your brush piles.

Brian

The one thing is the one thing
A dry fly catches no fish
Try not to be THAT 10%