There really aren't that many runnable rapids in the south channel and I wonder how many can be done without lining in late September. The rain that Mike mentions may help a bit but at the best of times, it is a portage-heavy route with the occasional rocky ride.
If you are starting from Katherine you have the following to deal with -
1. the set just as you leave Katharine - bouldery but do-able #13 in the Wilson count
2. the next set - a definite 240-meter portage on river left
3. Cabin Falls - a river left portage
4. Bridal Veil Falls - a 410-meter portage
5. a sequence of 3 sets of rapids which Wilson labels "Temptation Alley". He notes that it is “a classic boulder bash with three separate runs”. and that “all can be lined in the summer”. Last September around this time we decided to forego the 900-meter portage and go down the "alley". We spent an hour and a half lining and hauling our canoe through this section. Bad choice!
6. Fatman's Falls - another 120-meter portage
7. set of rapids just below Fatman's - #16 in Wilson's book - we lined the top ledge and lined and ran the rest in shallow water.
8. two final CI bouldery sets of rapids that we floated our way through. Your hope for "some of the less challenging rapids to avoid lining" may come down to these two. See the following Ottertooth page for notes on the south channel.
http://www.ottertooth.com/Temagami/Wils ... hannel.htmGood luck with your late September run down the South Channel. You still have a week and a half for more rain to up the water levels a titch more!