I'm still curious about what is downstream based on the picture posted by Groundcover in post #116? I can't tell if there are reflections of buildings in the stream or if there are actually structures in the water downstream that have restricted the flow of water?
The work spot in your picture looks like a muck spot that a person might sink to their knees in.
A log raft like Mark Twain's characters might have built might be a more dependable work platform if it were on cables that could be positioned up river of the jam so you could ferry yourself and debris back and forth between the jam and the bank.
Once you start clearing the jam, looks like there would be no suitable base to set your ladder on.