Went over and re-checked and learned something new. The flooding on the cycleway is intermittent and depends on the water level of the stream. At present, the cycleway is clear all the way up to the sourthern mouth of the tunnel and then becomes blocked with dirt. Last time I checked (when I made my edits, a few months ago), the water level was over the cycleway. I've got photographs, but I'm not sure what the best way to share them is. So, in conclusion I think you've gotten it right -- the only change needed would be marking the flooded tunnel and ford as intermittent. If that sounds appropriate to you then I'm happy to figure out the best tags to do that.