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Table of Contents
Foreword
Preface
Glossary

Chapter 16: Water Resources

16.56: The Red River Flood, May 1997

The 1997 “Flood of the Century” in the Red River Plains was the largest in the 20th century, possibly exceeded by only the 1826 flood. Much of the Red River Plain was inundated but by this date the structural measures prompted by the 1950 flood were in place. The floodway around Winnipeg existed, as did a dike, the west dike, extending west from the floodway inlet. Also ring dikes had been built around eight communities on the plain (Brunkild, Dominion City, Emerson, Letellier, Morris, St. Adolphe, St. Jean Baptiste, and Rosenort) as well as the Roseau River Anishinabe First Nation. These measures proved to be of great value, preventing flooding of the protected areas and reducing the damage caused. By 1997 radar imaging was an effective sensing mechanism, enabling coverage of the whole of the Red River Plain independent of lighting conditions and cloud cover.

The image shown here covers the central part of the Red River Plain from the Roseau River Anishinabe First Nation in the south 1 to Winnipeg in the north 2. It was obtained on May 11, 1997 at approximately 7:40 a.m.[i] This was slightly after the maximum extent of over-bank flooding which was on May 4. Although the inundated area had declined “significant reduction in inundation occurred only after May 15.”[ii] Areas of standing water have been enhanced with a blue colour.

The blue colouring shows clearly the flooded area, relatively narrow in the south and widening to the north. The course of the Red River can be traced from the southern edge 3, passing west of the Roseau River Anishinabe First Nation 4, east of St. Jean Baptiste 5, Morris 6, and St. Agathe 7, and west of St. Adolphe 8 before reaching the Floodway Inlet 9. The wide blue band east of Winnipeg is the Floodway 10, which at the time carried 48,500 cfs. The flow in the Red River was 93,000 cfs at Ste. Agathe and 104,000 cfs above the floodway. The course of the Red River through Winnipeg with evidence of flooding in some of the meander loops is very evident 11. The Roseau River Anishinabe First Nation, St. Jean, Morris, and St. Adolphe are protected by ring dikes and therefore appear as grey patches on the image. Morris, the largest of the settlements, is most obvious. An area east of it and the Red River is not flooded 12 which provokes the question “why was not a settlement located there rather than where St Morris is located?” The answer may lie in the fact that St. Morris was established and grew during the first half of the 20th century when there was little flooding, and the west bank location had some advantages over the east.

Further west, Rosenort 13 and Brunkild 14 are protected by ring dikes. Ste. Agathe 15 is flooded, although it was protected by a dike on its east (river) side. Also flooded was Grand Pointe 16, located on the Seine River just south of the floodway. “Farther away from the Red River, there is some localized flooding, particularly northwest of Brunkild 17. This flooding is due to melt water ponding on the low parts of sections of land as well as from smaller streams in the Red River Valley.”[iii] A similar explanation can be given for flooded areas west of the Floodway Inlet 18.

The location of the west dike west of the Floodway Inlet is easily detected by the difference between blue flooded areas and grey non-flooded areas 19. The dike built to prevent floodwater getting into the La Salle River 20 and flooding Winnipeg “by the back door” was successful in that respect. However, while it secured flood-free conditions for farmers north of it, those to the south endured flooded fields long past normal seeding time and were thus economically disadvantaged.

Other river channels that can be seen are 1) the Assiniboine River with flooding along some of its meanders west of 21 and within Winnipeg 22; 2) Shannon Creek, the straight blue line west of Morris 23; 3) Roseau River, a right bank tributary of the Red which flows through the Roseau River Anishinabe First Nation 24; and 4) the Rat River which joins the Red downstream from Ste. Agathe 25. However, Marsh River, which flows between the Red and the Rat, is completely obscured by floodwater.

Figure 16.56: The Red River Flood, May 1997

Figure 16.56: The Red River Flood, May 1997

Figure 16.56

Radarsat image

Scale: 1:374,000 (approx.)

Date: May 11, 1997

Location: Central Red River Plain

Map sheet: 1:250,000 62H Winnipeg

Notes

[ii] Wilson, B. A. and Rasid, H. “Monitoring the 1997 flood in the Red River Valley using hydrologic régimes and RADARSAT imagery”. The Canadian Geographer. vol. 9, no. 1., Spring 2005, 100-109.