See Table 1, River at Saskatoon, for a summary of conditions at the Gardiner Dam outlet and downstream in 2006- zero insects in the benthos.
Thesis by my graduate student, Rie Miyazaki, The Effect of Hayachine Dam on Downstream Aquatic Communities, U. of Saskatchewan, Saskatoon, Canada, 2006., 549 pp. see also
Another study of a dam on the Saskatchewan River done in my lab:
Mason, P.G. 1983. Systematics and ecology of Chironomidae (Diptera) associated with Tobin Lake reservoir and the Saskatchewan River. Ph.D. Thesis, Dept. of Biology, University of Saskatchewan, Saskatoon, SK.