April 18, 2009
Flood Media Bulletin #32
Flood Forecast
· Little precipitation is expected over southern Manitoba for the next five days.
City of Winnipeg
· The Red River in Winnipeg had declined to 6.4 metres (21 feet) by this morning and is now 0.46 m (1.5 ft.) below the crest observed on April 16.
· River levels in Winnipeg will decline to about 6.2 m (20.5 ft.) by Sunday morning and will then begin to decline less rapidly as the Assiniboine River flow reaches a minimum and the gates at the floodway control structure are gradually lowered.
· The Red River watershed is saturated at this time and, as a result, river levels would be quickly affected if significant rainfall develops in the coming weeks. It is estimated that the river level could still be at 4.6 m (15 ft.) in mid-May even with normal precipitation from now on. Another crest is quite possible if heavy rain develops during the next three weeks.
· The crest of 6.9 m (22.5 ft.) at James Avenue in Winnipeg was the second highest since major flood control works began operation in 1969. The crest was 7.5 m (24.5 ft.) in 1997.
Lockport to Breezy Point
· Levels in this portion continue to decline slowly. The river level in Selkirk has declined 9.1 centimetres (3.6 inches) during the past two days. Levels will begin to decline a little faster next week.
Emerson to St. Adolphe
· The Red River was at its crest from St. Adolphe to the floodway inlet this morning. Levels will begin a very gradual decline later today.
· The level at Ste. Agathe is expected to crest tomorrow with only a slight further rise.
· There was no change in the level at Morris since yesterday.
· The river rose slightly at Letellier and St. Jean Baptiste due to wind and will decline again by late today as winds decrease.
· The level at Emerson is falling very slowly for the second day after being virtually unchanged for an entire week.
· Residents and flood fighters in the flooded area are reminded that strong winds and wave action can raise water levels by 0.3 m (one ft.) or more and can erode dikes. However, strong winds are not in the forecast for the next few days.
· The Red River is approximately 16 kilometres (10 miles) wide at Morris, well beyond its usual average width of 200 m.
· Levels in the United States portion are continuing to decline slowly.
· So far this spring, the Red River has risen 10.39 m (34.1 ft.) at Morris and 10.36 m (34 ft.) at the floodway inlet.
Floodway Inlet
· Normal operation of the floodway gates continues with adjustments to maintain water levels south of the inlet at natural levels.
· The water level upstream of the floodway inlet this morning was 233.7 m (766.75 ft.), a rise of 5.5 cm (2.2 in.) since yesterday morning. The flow into the Red River Floodway this morning was estimated at 42,500 cubic feet per second (cfs) of a total 96,000 cfs upstream of the floodway inlet.
Assiniboine River
· Flow into Portage Reservoir declined from 17,700 cfs yesterday morning to 16,310 cfs this morning. A gradual decline is expected to continue for the next five days. The flow in the Portage Diversion this morning was 15,780 cfs and the flow in the river downstream was 520 cfs. River flows toward Winnipeg will be increased once levels in the city of Winnipeg are below flood stage.
· Assiniboine River levels from the area of Lido Plage Road to Winnipeg will continue to decline quite rapidly for the next two days and will then fall more gradually.
· Flooding continues along the Assiniboine River from St. Lazare to Brandon. The crest is presently at Brandon. Valley flooding should end within a week or so if there is little rain, but it will take additional weeks for water to drain from the valley floor.
· The outflow from Shellmouth Reservoir remains at 50 cfs. The reservoir water level has risen 21 cm (8.3 in.) since yesterday and stood at 425.5 m (1,396.1 ft.) this morning. The level is expected to rise to at least 426.7 m (1,400 ft) by the end of April. The normal summer level is 427.5 m (1,402.5 ft.)
Souris River
· Levels of the Souris River in Manitoba are beginning to rise more rapidly in the Coulter area. Over-bank flows are still limited to the Coulter area, but will spread to areas further north by late next week. A crest exceeding that of 1999 by about .3 m (one ft.) is expected at the end of April or in early May. Some diking will be required in the south portions of Melita and just south of Souris. Extensive agricultural flooding will occur.
Pembina River
· Serious flooding of the entire Pembina Valley continues.
· The crest presently at La Rivière is 22.9 cm (0.75 ft.) higher than that of 2006. Sandbagging efforts at Holiday Mountain Resort have been successful.
· The river is still overflowing PTH 34 near Swan Lake but the depth of overflow has decreased from .52 m (1.7 ft.) yesterday to .37 m (1.2 ft.) today.
· Levels from Rock Lake to La Rivière are similar to those of 1974, which was among the largest floods in recent decades.
· A peak discharge of 14,000 cfs is expected at Windygates early on Sunday, exceeding the extreme crest of 2006 at this location.
· Rock Lake has declined 24.3 cm (0.8 ft.) since yesterday and was at 408 m (1,338.3 ft) this morning. This crest two days ago was among the highest on record.
· The U.S. National Weather Service is predicting another significant crest at Walhalla based on the crest now approaching Windygates. However, they expected only a minor rise of three cm (1.2 in.) to 6.6 m (21.6 ft,) at Neche on April 22, which is six cm (2.4 in.) higher than that of 2006. Based on this forecast, there would be little boundary overflow unless strong south winds develop during the next 10 days or so.
· Manitoba Water Stewardship and Manitoba Infrastructure and Transportation staff are closely monitoring possible overflows at the international border. Actions have been taken to protect Gretna and Halbstadt from possible flooding due to overflows.
Other Rivers
· Both the Fisher River and the Icelandic River have crested or are presently at their crest. Minor over-bank flows are occurring with flooding in low-lying areas such as the Peguis First Nation and the community of Fisher River. Flooding is expected to end by early next week. Diking has occurred at Peguis Reserve.
· Extensive overland flooding continues in the Interlake region with many roads overtopped or washed out. Conditions will begin to improve next week if the weather is favourable, but some flooding will continue for several weeks.
· All tributaries of the Red River had crested as of this morning, except for areas affected by backwater from the Red River.
· The flood potential for the Westlake area is quite low. Minor localized flooding may occur late next week.
· The flood potential remains low from Swan River to The Pas.
Overland Flooding:
· Overland flooding continues in many portions of southern Manitoba, especially in the Red River Valley and the Interlake, and this will continue through the weekend but should be generally subsiding. Residents in low-lying areas are advised to take precautions against possible sudden rises.
· Further details are provided below and specific forecasted crest stages are shown on the daily flood sheets issued by Manitoba Water Stewardship. This information may be viewed at www.gov.mb.ca/waterstewardship/floodinfo/floodsheet.html.
Flood Response
· Overland flooding continues to be a problem throughout the Interlake. Municipal road washouts and culvert washouts continue to pose a problem. Steamers have been deployed to the Interlake region.
· Additional sandbags are being delivered to Melita where staff from Manitoba Infrastructure and Transportation are constructing a 750 m (2,460 ft.) dike along PTH 3. In addition, the town and the rural municipality are working together to raise the town’s earth dike.
· Sandbags have been sent to the RMs of Pembina, Souris and Argyle.
· There has been extensive flood damage at Peguis with approximately 100 homes affected.
· There are approximately 1,923 people evacuated because of the flood. About 1,266 are from First Nations communities and 657 are registered through the Red Cross. The number is not exact as some individuals or families have evacuated voluntarily but not registered.
Flood information is available at www.manitoba.ca.
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