Strange time to start with an in-stream project.........but I guess if you are the ones who issue the permits anything is possible. I assume that the de-watering of the old channel will be taking place slowly and hopefully as many fish as possible will be salvaged before it is completed.
Good point about the electo-fishing difficulties with fry in large substrate bentrod, I do not agree with removing the brush below the hatchery though. I have salvaged suicide and coldwater before dewatering for pipeline crossings or gravel removal and the fry are very hard to get out. Many will be lost on the Chehalis if the old channel is completely dried up no matter what the salvage efforts are.
As for the folks who are saying "about time" etc, they have dug a new channel several times over the past few years to divert the water but it always re-routs itself. If they do a good job with the rip-rap dyking this diversion will probably last more than 1 high water unlike previous attempts.
As for the way the river was back when you could drive right in to Pretty's, I miss it very much as well. I caught my first settlie in that area 16 years ago and can still remember many of the old runs....
Any river fisher has to have a long memory to keep track of all the "Favorite Holes" they have loved and lost over the years...... All the more reason to keep exploring I guess!