I haven't been on the Upper Section but I have done the lower and studied the history of the water gauges
http://www.cehq.gouv.qc.ca/suivihydro/g ... ion=080809 (graph of the last 12 months)
http://www.cehq.gouv.qc.ca/suivihydro/g ... ion=080809 (text list day by day for the last 46 years)
http://www.cehq.gouv.qc.ca/depot/histor ... _Q_MAX.txt (monthly maximums 46 years)
http://www.cehq.gouv.qc.ca/depot/histor ... _Q_MIN.txt (monthly minimums 46 years)
http://www.cehq.gouv.qc.ca/depot/histor ... _Q_MOY.txt (monthly average 46 years)
I was on the river late August - early September 2004, levels on the gauge 260 rising to 330cms, that's high for that time of year and it sure felt high.
Summer levels are quite variable, you'll have to have a look at the historical numbers to get a feel for the "normal" for July. I had a quick look at the last link, seems like the super dry 2011 was the only year where levels might actually be considered "very low" and many years the levels are definitely "fairly high".
I'd like to get back for the full river some time, I would be hoping for levels +/- 200cms, at least that's my guess for the best chance I'd actually be able to run some of the bigger rapids or get past with easy lining or liftovers.
The Lester Kovac guide
https://sites.google.com/site/landltrip ... adback2005 was done at 145cms and falling to give that report some context. Possibly important is that lower water would expose more potential camp locations especially on the upper open water sections.