South Saskatchewan River
The South Saskatchewan River is a major river in Canada that flows through the provinces of Alberta and Saskatchewan. For the first half of the 20th century, the South Saskatchewan would completely freeze over during winter, creating spectacular ice breaks and dangerous conditions in Saskatoon, Medicine Hat and elsewhere. At least one bridge in Saskatoon was destroyed by ice carried by the river. The construction of the Gardiner Dam in the 1960s, however, lessened the power of the river by diverting a substantial portion of the South Saskatchewan's natural flow into the Qu'Appelle River. By the  1980s many permanent sandbars had formed due to the lowering of the level of the river. From the headwaters of the Bow River, the South Saskatchewan flows for . At its mouth at Saskatchewan River Forks, it has an average discharge of and has a watershed of , 1,800 of which are in Montana in the United States and in Alberta and Saskatchewan. Course. The river originates at the confluence of the Bow and Oldman rivers north of Grassy Lake, Alberta at the incorporated community of Bow Island, not to be confused with the town of Bow Island, Alberta. The waters of  these two rivers, in turn, originate from winter snowpack and rainfall in the Rocky Mountains near the British Columbia and Montana border. Glacier and snowmelt from the Rocky Mountains and foothills contributes nearly 90% of the annual flow, with most of that contribution during July and August. The Red Deer River is a major tributary of the South Saskatchewan merging east of the Alberta-Saskatchewan border. The Lake Diefenbaker reservoir was created with the construction of the Gardiner and Qu'Appelle River dams in Saskatchewan. Water from the South Saskatchewan flowing through the dams provides approximately 19 percent of the hydro -electricity generated by SaskPower. Downstream from the dam the river flows north through Saskatoon and joins the North Saskatchewan River east of Prince Albert at the Saskatchewan River Forks — thus forming the Saskatchewan River. For approximately near Saskatoon, the Meewasin Valley Authority is responsible for conservation of the river environment. Numerous lakes in the Saskatoon area were formed by oxbows of the South Saskatchewan River, most notably Moon Lake and Pike Lake. A 2009 report, produced by WWF-Canada which analysed the river flow on 10 major Canadian rivers reported that the South Saskatchewan River was the most at risk . Climate change, agricultural and urban infrastructure water use, and dams producing hydroelectricity, have all combined to reduce the flow of the South Saskatchewan River by 70 percent. Developers and governments have been cautioned to protect and restore the river with sustainable projects and limit water diversion. Dickson Dam regulates water supply downstream on the Red Deer River; the Bassano Dam and 11 other dams divert water on the Bow River and in the Bow River basin; and the Oldman River Dam and Waterton-St. Mary Headworks System manage water flow downstream of the Oldman River. The proposed Meridian dam west  of Leader and north east of Medicine Hat was cancelled due to project costs outweighing the irrigation benefits. Islands. Partial list Geology. Sections of the riverbank along the South Saskatchewan River are prone to slumping. Since its founding, the city of Saskatoon has dealt with a number of slope failures. Controlling riverbank development was a factor in establishing the Meewasin Valley Authority in 1979. Fish species. Fish species include walleye, sauger, yellow perch, northern pike, lake trout, rainbow trout, goldeye, lake whitefish, cisco, lake sturgeon, burbot, quillback, longnose sucker, white sucker and shorthead redhorse.