Flow : approx 37 cms coming into Bark Lake (estimate based on outflow and lake level)
There is no online gauge for the Upper Mad/Opeongo. If you can find out the inflow into Bark Lake, it is usually about 1/3 Opeongo, 2/3 Mad.
Class 3/4/5 The most difficult section of the Madawaska, the Upper Mad can be paddled in several sections, with the lower section accessible by an old rail bed. The section from Whitney to Hermans chute is a class 3/4 run with longer rapids than many southern Ontario runs. Below Hermans are several large, difficult drops, including the seldom-run Little Niagara.
120 cms (combined flow): lots of water on Upper Mad: large wavetrains, long continuous rapids.
Good level on Opeongo as well: plenty of water.
From ice-out to mid-late May. Dam controlled. The season on the Upper Mad is often shortened by difficult access: in early May, the river may be running and ice-free, but the access road is often snow/ice covered, or difficult