As I was crossing the Donghe bridge today I noticed that the extremely muddy water flowing from the river into the ocean was indeed flowing north in the ocean. I'll be looking for that hinoki.

What we should do is make a trip south of Zhiben to one of the rivers. We don't have to go all the way to Dawu. I know of a good one that's a bit closer, south of Taimali, north of Dawu. Anything coming down from there is indeed from the central mountain range, from Dawu Mt. This river valley I'm thinking of is protected; there's no road access after a few KM. So, there should be plenty of driftwood after a big storm like this.