By looking here.. https://www.lrl.usace.army.mil/Missi...-Quality-Data/
It appears water column is pretty stable in regards to temp and O2. I don’t think the walleyes will hang around in water with less than 4mg/l of dissolved O2. I don’t think they will follow the smaller forage like the bass will this time of year, moving into Oct. and the bigger baits will be deeper. My guess is 20-30’ or wherever you see bait adjacent to cover.