Province of Manitoba | Archived News Releases

May 21, 2011

Flood Bulletin #56

Flood Response

There is considerable activity to build sandbag dikes at cottages and residences around Lake Manitoba. Municipalities around the lake are working with residents to survey and mark properties to establish protection levels.
There are approximately 500,000 sandbags in the St. Laurent and Twin Beaches areas.
Super sandbags are being installed in the Delta Beach area to maintain road access.
Sandbagging is continuing around Dauphin Lake and a road has been raised to maintain access. Dauphin Lake is at record water levels and has likely crested. Flows at the outlet of Lake Dauphin at Mossy River Dam were measured yesterday at 3,000 cubic feet per second (cfs). The dam has been fully open continuously since May 2010.
Cottagers are encouraged to put flood structures in place to protect their property and to move cottage contents to safer and higher ground.
The RM of Alonsa has issued a precautionary evacuation notice for 32 residents. Dikes are being built around these homes.
Conditions around the Portage Diversion structures, including the channel dikes, and the Assiniboine River dikes are stable and being monitored closely as river levels gradually fall. The controlled release point at the Hoop and Holler Bend was closed yesterday at noon. There is a remote possibility that the release point could be reopened if there are issues on the Portage Diversion channel or along the Assiniboine River dikes.
Residents in the controlled release area are advised to maintain their flood protection structures for at least another week. The voluntary evacuation for most residents in the area has been lifted. Residents with homes closest to the release point remain evacuated.
A mandatory evacuation for 15 homes around the Portage Diversion channel remains in place.
In Brandon, businesses are beginning to restore operations in the evacuated area around the Corral Centre with the expectation of reopening on Tuesday.
There are 3,409 Manitobans evacuated from their homes. In Brandon there are 1,399 people evacuated.

Flood Forecast

An unstable weather system has resulted in rain in southern Manitoba ranging from 30 millimetres in the Melita area to five mm in the lower Assiniboine River Basin. Rain is expected to continue today and tomorrow.
Due to the current and expected rainfall, several tributaries in both the Assiniboine and the Red River Basin will experience slower declines in water levels or minor rises in the next two to three days. If heavy and widespread rains develop, both the Souris and the Assiniboine rivers will see another crest, but it will be lower than the previous crests this month. Much will depend on how the rainfall is distributed over the watersheds. The impact of the rainfall is being evaluated this weekend as conditions evolve.
Environment Canada has issued a strong-wind warning for both Lake Manitoba and Lake Winnipeg today with east winds at 35 to 40 km/h. Winds on Lake St. Martin, the Shoal Lakes and Lake Pineimuta will be east at 30 km/h. Winds on Oak, Pelican and Rock lakes will be east at 40 km/h, gusting up to 60 km/h today.
Flood warnings are in effect for the Assiniboine River at all points downstream of the Shellmouth Dam; Pipestone Creek, all reaches; Oak and Plum lakes; Plum Creek to the Souris River (including the town of Souris); and the Qu`Appelle River in the St. Lazare area.
A high water advisory is in effect for all major lakes in Manitoba and the Souris River

Lakes

Maps illustrating forecast peak lake levels and water levels that would occur with a sustained 60 km/h wind are available online at www.gov.mb.ca/flooding/index.html. Wave uprush is not illustrated on the inundation maps due to the site-specific circumstances of each property.
Information on how wave uprush may impact individual properties is available at https://www.manitoba.ca/waterstewardship/floodinfo/lakes_information.html#inundation_maps.
Lake levels at Oak and Plum lakes are high and continue to contribute high flows to Plum Creek.
The Fairford River water control structure continues to operate at full capacity due to the high level of Lake Manitoba. Outflows from Lake Manitoba on the Fairford River and further downstream on the Dauphin River are the highest ever measured.

Lake Levels

Lake	Level¹ (ft.)	Change from Last Reading (ft.)	Date of Previous Reading
Lake Manitoba	814.96 (taken May 21)	+0.09	May 20
Lake St. Martin	804.24 (taken May 21)	no change	May 20
Lake Winnipeg³	716.44 (taken May 21)	+0.04	May 20
Lake Pineimuta	806.96²(taken May 20)	+0.03	May 19
Dauphin Lake	859.44 (taken May 21)	no change	May 20
Oak Lake	1,412.04 (taken May 21)	-0.16	May 20
North Shoal Lake	860.47 (taken May 20)	-0.02	May 18
East Shoal Lake	860.90 (taken May 20)	-0.01	May 18
West Shoal Lake	860.85 (taken May 20)	no change	May 18

¹Wind effect eliminated

²Reading may be influenced by wind

³Lake Winnipeg at Gimli

Assiniboine River

Water levels on the Qu’Appelle River at Welby are 17.03 ft. today and are anticipated to increase with the forecast rain on the weekend.
Water levels on the Shellmouth Reservoir are 1,413.30 ft., decreasing 0.21 ft. since yesterday. Inflow into the Shellmouth Reservoir is 6,900 cfs and outflow today is 8,475 cfs.
Water levels on the Assiniboine River at the First Street Bridge in Brandon are 1,180.14 ft., decreasing 0.4 ft. since yesterday. Flows at the First Street Bridge in Brandon are 27,150 cfs, measured this morning. It is estimated that the Assiniboine River water levels at First Street in Brandon will be close to 1,177 ft. by the end of May, a decline of about three ft. from the current level. The flows are being reassessed to include the forecast rainfall in both the Qu’Appelle River and upstream areas.
Inflow upstream of Portage la Prairie is 48,480 cfs. Flows in the Portage Diversion channel this morning are at 30,610 cfs. Flows on the Assiniboine River at the Portage Reservoir control gates are 17,870 cfs.
Water levels in the Baie St. Paul area remain at 799.87 ft., with no change since yesterday.

Souris River

Due to the current forecast rain, the flood watch for the Souris River has been downgraded to a high water advisory.
Water levels on Plum Creek have increased to 1,377.2 ft. today. These high flows will continue and be sustained for a significant period of time due to the high levels of the Plum and Oak lakes.
Water levels on the Souris River at Wawanesa decreased 0.08 ft. since yesterday to 1,155.72 ft. today, with an estimated flow of 14,050 cfs. Based on this weekend’s forecasted rain, the Souris River at Wawanesa is expected to see another crest of approximately 14,000 cfs around May 26. The crest will be well below the earlier crest in April.

For more information, see www.manitoba.ca/flooding. The most up-to-date highway information is at www.gov.mb.ca/mit/roadinfoor 1-877-MBRoads (1-877-627-6237) and on Twitter by following @MBGov.

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Après la publication de chaque rapport sur les inondations, les renseignements sont mis à jour en français dès que possible.

Pour les consulter, allez à www.gov.mb.ca/waterstewardship/floodinfo/forecasts_reports.htmlpuis cliquez sur « Daily Flood Reports».

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