From King County Parks via the Cascade Blog, looks like a portion will be shut down for a few weeks:
In order to repair the levee, King County must close its Cedar River Trail from Aug. 16 to Sept. 3 while the work is under way.
The trail will be closed to all use between 154th Place Southeast and 175th Avenue Southeast, just east of Renton’s Ron Regis Park. The trail will be closed 24 hours a day, and there will be no flagged reroute during construction.
Full post is here.