Search Textbook

Table of Contents
Foreword
Preface
Glossary

Chapter 16: Water Resources

16.43: The Assiniboine Valley Near Virden

This air photo covers part of the Assiniboine Valley shown in figure 16.42. The southward-flowing Assiniboine River 1 is light-toned due to light reflecting from sediment-laden water. An abandoned channel 2 clearly visible here is not seen on the radar image in figure 16.41 because it was completely submerged by floodwater. The tree cover in the flood plain 3 can be identified, but it is not as obvious as the light-toned representation on figures 16.41 and 16.42. The wooded west wall of the Assiniboine Spillway is dark-toned 4, whereas the more sparsely wooded east wall is lighter-toned 5,the same arrangements as on the radar image in figure 16.42 but for different reasons: in this case the light tone results from light reflected from grasses. PR 259 6 is clearly visible, but the pylons of the power lines, so obvious on the radar image in figure 16.42 can only just be discerned using a magnifying glass on the original photo 7. Note also the dike east of the Assiniboine 8 built to contain floodwaters. Clearly it was not successful in 1995 as on both figure 16.41 and 16.42 the dark area representing floodwaters extends right to the east wall of the spillway. Possibly the dike was allowed to deteriorate after the Shellmouth Dam was built upstream in 1967, the landowners having a false sense of security from the existence of the dam. However, although Shellmouth was expected to reduce flooding in the Assiniboine Valley, it was never claimed that it would eliminate flooding.

Figure 16.43: The Assiniboine Valley Near Virden

Figure 16.43: The Assiniboine Valley Near Virden

Figure 16.43

Vertical air photograph: A16429-40

Flight height: 10,300 feet a.s.l.; lens focal length: 152.4 mm

Scale: 1:17,100 (approx.)

Date: October 29, 1958

Location: Township 10; Range 25WI

Map sheets: 1:250,000 62F Virden

1:50,000 62F/15 Virden