Manitoba has an abundant supply of surface water with many large lakes and thousands of smaller ones (chapter 2). However, much of the water is in the north or drains to the north where there is a sparse population. In the south dams and reservoirs have been constructed to conserve water in some areas, whereas in other places projects were designed to drain water from the land to make it suitable for cultivation. The province’s rivers offered enormous potential for hydroelectric power, much of which has now been exploited, starting with a small-scale project on the Little Saskatchewan River and progressing to large projects on the Winnipeg, Saskatchewan and Nelson rivers. Two thermal power stations at Brandon and Selkirk on the Assiniboine and Red rivers illustrate the need for an assurred water supply. Flooding has been a problem since the earliest days of the province, especially along the Assiniboine and Red rivers culminating in the 1997 “Flood of the Century” in the Red RiverValley. Dams, diversions and ring dikes are used to divert the floodwaters to less critical areas.
16.39: Flooding in and near the Little Saskatchewan River Valley
This spring photo shows the upper reaches of the Little Saskatchewan River 1 between RidingMountainNational Park, off the photo to the north, and the Keeseekoowenin First Nation 2 in the south. The meanders of the Little Saskatchewan River 3 can be seen but are partly obscured by the fact that the valley floor 4 is flooded and therefore dark-toned. This area is covered by ground moraine with numerous small lakes (sloughs) in the hollows 5. All the sloughs west of the river are mapped as intermittent lakes on the 1:50,000 map of the area[i], but at the time the photo was taken, soon after snow melt, they are all water-filled. The same is true of lakes east of the river with the exception of one large lake in the northeast that is mapped as a permanent lake 6.
Note the variation in lake tone from almost black in the west 7 to almost white—due to specular reflection—in the southeast 8. Note also the difference in land use between the First Nations—almost completely wooded—and the surrounding area—mainly cleared for agriculture.
Figure 16.39: Flooding in and near the Little Saskatchewan River Valley
Vertical air photograph: A15226-8
Flight height: 20,000 feet a.s.l.; lens focal length: 152.26 mm