Here are a few links:
Public notice document
http://a123.g.akamai.net/7/123/11558/abc123/forestservic.download.akamai.com/11558/www/nepa/102429_FSPLT3_3951239.pdf

The actual FEA document from the forest service
http://a123.g.akamai.net/7/123/11558/abc123/forestservic.download.akamai.com/11558/www/nepa/102429_FSPLT3_3950878.pdf

The main point of concern.
https://www.google.com/maps/dir/47.6632777,-120.2246838/47.9155331,-120.4963181/@47.9148408,-120.4959978,203m/data=!3m1!1e3!4m2!4m1!3e0

I am 98% sure that riprap B is located at this point, which is directly above the last drop on the iv+ section of the Entiat.

I am going to write an email to the FS saying this:

objections-pnw-okanogan-wenatchee@fs.fed.us
Subject:
Objection regarding Upper Stillwaters and Story A Restoration Project

I am writing to comment on the Final Environmental Assessment document for the Upper Stillwaters project. The location of the Riprap Enhancement B site is directly above a regularly run whitewater rapid on the Entiat river. I am concerned that the location of this structure may pose a safety hazard for kayakers on this section of river.

A description of this run is located at:
https://www.americanwhitewater.org/content/River/detail/id/2114/

I hope that there is still time to evaluate these locations with whitewater kayaker's safety and river use in mind.