So, before signing off, let s look at this. BUT, if you are on a wide enough stream, it is possible to wade without kicking debris directly into the areas you are fishing. On my home stream, the Huron River, standard practice is to wade down the middle and cast to both shoreline areas. In these instances, my downstream cast is quartered, but the principles still apply. Also, fish have a number of senses that aid them in detecting your presence.
Sight is one, but the lateral line and hearing senses are also keen, as are the olfactory senses.
Sloppy wading, whether from up- or downstream, will alert a fish. Since sound travels much better through water than air, I would say that vibrations from walking and wading likely represent at least as big a problem as visual spooking.