The problem with wood piling up against, and endangering, bridges is the fault of the bridges, not the wood. Those bridges all have footings in the river that are just begging to catch debris and be washed away. They are built that way, rather than spanning the river, because it is cheaper. Penny wise and pound foolish if you ask me

BTW, I'd bet that very little of the wood you saw being removed from the Skagit was placed there for fish enhancement purposes.