May 31, 2010
Flooding Continues in Southern Manitoba
Extensive over-land flooding continues in many areas of southern Manitoba due to run-off from recent heavy rains falling on saturated ground. Many small streams in areas that received heavy rain are still over their banks, especially in low-lying areas, and much water remains on fields.
Most streams which have particularly high levels are cresting and will begin falling slowly today and more rapidly later this week. This includes the Morris and La Salle rivers, Sturgeon Creek, the Roseau River near Dominion City, the Little Saskatchewan River near Rivers and many other small streams. Flooding should end within a few days but significant water will remain on low-lying areas and fields until next week, even with favourable weather.
Levels of the Red River rose an additional 0.6 to 0.9 metres (two to three feet) from Drayton, N.D., to the floodway inlet during the 24-hour period ending at 9 a.m., today. The total rise for the last three days is now about 3.1 m (10 ft.). Additional rises of about 0.9 m (three ft.) are expected with crests occurring late this week. The river will remain generally within its banks but some flooding of low‑lying lands in the Red River Valley is expected in the St. Jean Baptiste area. Pumping stations in valley towns continue to be operated to assist with drainage. Levels of the Red River in the Selkirk area will rise another 0.6 m (two ft.) or so with the crest about June 5.
The Red River in downtown Winnipeg rose 0.5 m (1.5 ft.) since yesterday and stood at 5.5 m (18 ft.) this morning. A crest near 5.6 m (18.5 ft.) is expected late today or early tomorrow. The early crest is expected due to operation of flood-control works and an expected decline in high flows on smaller streams in the Winnipeg area.
The Red River Floodway was put into operation at 5:30 p.m. yesterday and is reducing levels in Winnipeg. In compliance with the floodway operating rules, natural water levels are being maintained at the floodway inlet. Increased diversions into the floodway will be possible beginning tomorrow as the effect of Portage Diversion operation reaches Winnipeg.
Levels of the Assiniboine River are high but the river will remain within its banks. The river crested at Brandon and Headingley earlier today, but rises continue in the Miniota area and from Spruce Woods Park to Portage La Prairie. The Portage Diversion is being operated to reduce water flows toward Winnipeg. The diversion flow this morning was 2,100 cubic feet per second (cfs) while the flow down the river was 1,300 cfs. Flows in excess of 1,200 cfs will be diverted until river levels subside to 4.3 m (14 ft.) at James Avenue in Winnipeg. The diversions will have little effect on Lake Manitoba levels.
The Shellmouth Reservoir continues to be operated to reduce flow on the Assiniboine River. The level this morning was 428 m (1,404.19 ft.), about 0.5 m (1.5 ft.) above the summer target level. The level is expected to rise to near 428 m (1,405 ft.) due to run-off from recent rain. The inflow this morning was 1,400 cfs and the outflow was 1,200 cfs. The present outflow will be maintained until the reservoir subsides to 427.6 m (1,403 ft.).
In addition to operation of the Red River Floodway, the Portage Diversion, Shellmouth Reservoir and other dams are being operated throughout southern Manitoba in order to reduce levels of lakes and reservoirs and to reduce downstream river flows.
Streams in eastern Manitoba, the Interlake and the Westman region are well above average flow and levels. There is some flooding in the northern Whiteshell and Nopiming parks. Some flooding is also underway in the Turtle and Whitemud river watersheds and on tributaries of the Assiniboine River from St. Lazare to Winnipeg. The Turtle River crested at St. Rose last night.
Weather forecast information shows a few showers may occur later today and tonight but amounts should be minimal. Some showers are expected from late Thursday through the weekend but daily amounts are not forecast to exceed 10 millimetres and this amount of additional rain would not have a substantial effect on river levels.
The latest information on water levels and outlook reports is available at:
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