It wasn’t so much the slides but the slides went into Stillman Creek which went into the Chehalis River. The town of Chehalis was flooded and the slides are getting the blame. Deserved? I don’t know, but I do know that they may have had an effect on the Chehalis River flooding. The rainfall itself was the biggest problem.
Chehalis has always flooded. It is built on a floodplain, and the bottomland has become prime retail real estate for some bizarre reason. There are more buildings and businesses to be flooded than ever, hence the devastation is worse than ever.