May 6, 2011
Flood Bulletin #35
Flood Forecast Summary
- The Assiniboine River forecast has been revised with record flows forecast for the Brandon area at 32,000 cubic feet per second (cfs) between May 12 and 14. The forecast peak water levels are between 1,182.5 and 1,183 feet. The upgraded Brandon dikes are built to provide protection to 1,184 ft.
- Water levels on the Assiniboine River at the First Street Bridge in Brandon are 1,180.4 ft., increasing 0.47 ft. since yesterday, exceeding the record level of 1,180 ft. set in 1923 at the First Street Bridge. These levels are approaching previous historic floods in 1904 and 1882.
- The adjustments to the Assiniboine River forecast were necessary due to inaccurate readings from a faulty gauge on the Qu’Appelle River in Saskatchewan. The gauge and all associated readings have now been rechecked and the forecast adjusted accordingly.
- Flows in the Portage Diversion channel this morning are at 20,000 cfs. Inflows upstream of Portage la Prairie are 38,000 cfs. Flows on the Assiniboine River at the diversion will be held at 18,000 cfs for an extended period of time. Flows further downstream on the Assiniboine River may be higher than this level due to run-off from local flows after rainfall.
- Water levels on the Assiniboine River from Baie St. Paul to Headingley are forecast to receive sustained high flows for an extended period of time. Despite regulation of Assiniboine River flows, inflows from local run-off following any future rainfall may increase water levels in the area a further 0.5 ft. for a few days after the rainfall.
- St-Lazare has crested at 1,292 ft. and is now declining.
- The Assiniboine River forecast for Sioux Valley has also been revised upwards for forecast peak water levels between 1,204.7 to 1,205.2 ft. The Sioux Valley First Nation dikes provide flood protection level to 1,207 ft.
- Flood warnings are in place for streams and rivers in the Dauphin Lake Basin; streams and rivers east of the Duck Mountains; the Souris River from Melita and all downstream reaches; the Assiniboine River downstream of Shellmouth Dam to Portage la Prairie; Pipestone Creek, all reaches; Oak Lake and Plum Lakes; Plum Creek to the Souris River (including the town of Souris); the Qu’Appelle River in the St-Lazare area; and the Assiniboine River downstream of Portage la Prairie.
- A high water advisory is in place for all major lakes in Manitoba.
Flood Response
- In Brandon along 18th Street, Manitoba Infrastructure and Transportation will widen the base of the existing super-sandbag dikes to add a third row of super sandbags. Work is underway to add an additional row of super sandbags behind the existing super-sandbag dike along First Street next week. This will provide additional freeboard protection along the Assiniboine River.
- Residents of the rural municipalities of Cartier, St. Francois Xavier and Headingley along the Assiniboine River are raising their dikes an additional two feet above the existing water level to provide for protection against anticipated rain and potential wind setup. Provincial sandbags are being provided to the municipalities, which are helping to organize the raising of individual dikes over the weekend.
- As a precautionary measure, construction of a 400-metre secondary dike behind a section of the primary, permanent dikes along the Assiniboine River is expected to begin this weekend. The affected section is between Poplar Point and the Baie St. Paul Bridge where ice-induced damage affected some areas of the dike in mid-April.
- The RM of Ochre River near Dauphin Lake has declared a state of local emergency and is doing work along the shoreline to drain overland water and protect area homes. Ten additional residences are being sandbagged and there are a number of homes that still have sandbag protection in place following a fall rainstorm.
- Manitoba Agriculture, Food and Rural Initiatives has been in contact with 34 producers in the Shoal Lakes area. Work is underway to ensure livestock have enough feed and to develop plans to move herds as required due to rising lake levels. Preliminary evacuation plans are also being made with five families, the local municipality and the province.
- Flood-tube barriers are being provided to the Ashern area to protect homes around the Kernsted Beach area from rising Lake Manitoba waters.
- Two private sandbag dikes put up by homeowners outside of the town of St. Lazare’s community ring dike were overtopped, flooding the basements of two homes.
- Approximately 21 long-term care residents of the Wawanesa Health Centre have returned to the facility. It was evacuated on April 14 on a precautionary basis due to high water levels on the Souris River.
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Flood liaison staff are still available to provide provincewide assistance at 1-866-626-4862
(toll-free) or 945-3744 for flood liaison assistance. - There are 1,134 people evacuated from their homes, largely due to loss of road access. All evacuees from the Roseau River First Nation have returned home.
- There are 106 provincial roads affected by flooding, with 70 closed. There are approximately 685 municipal roads closed.
Flood Forecast
Red River
- Water levels just upstream of the Red River Floodway inlet are 763.95 ft., with flows of 73,500 cfs. Flows in the floodway are approximately 34,700 cfs.
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In Winnipeg, the Red River has held a sustained open-water crest at 19.6 ft. for the last two days in Winnipeg at James Avenue. Flows at James Avenue this morning were approximately
58,800 cfs.
Assiniboine River
- Without flood protection provided by the Shellmouth Reservoir and the Portage Diversion, water levels in the Baie St. Paul to Headingley area would be about four to five ft. higher than today’s levels.
- The flood warning for the Assiniboine River from the Shellmouth Bridge to Portage la Prairie has been extended to the Shellmouth Dam area.
- The flood watch for the Assiniboine River downstream of Portage la Prairie has been upgraded to a flood warning.
Souris River
- Water levels at Melita are 1,410.3 ft. today.
- Plum Creek, a western tributary of the Souris River, increased 0.05 ft. since yesterday.
Other Major Waterways
- Many streams throughout the Dauphin Lake Basin and further north in the Lake Winnipegosis Basin declined since yesterday. It is anticipated that Dauphin Lake will be near flood stage over the next few days and is forecast to reach a peak water level of 858.2 ft.
- Streams on the west side of Lake Winnipegosis have exceeded bank-full in many locations. High flows on the Garland River caused significant overland flooding and washed out roads.
- Forecasters have estimated peak wind-eliminated water levels for Lake Manitoba and Lake St. Martin. Lake Manitoba water levels are forecast to reach between 814.2 and 814.6 ft. around June 4. Lake St. Martin water levels are forecast to reach 804.6 ft. or higher around July 1. These forecast elevations are preliminary at this time and may be revised with major weather changes and as computer models are refined.
- Lake Manitoba water levels have risen to 814.18 ft., increasing 0.1 ft. since yesterday. Lake St. Martin water levels have risen to 803.46 ft., increasing 0.05 ft. since yesterday.
- Outflows from Lake Manitoba at the Fairford Dam are estimated at 13,000 cfs as of late yesterday. This flow value is subject to review and will be reassessed later today.
- Open water is visible on the lower half of Lake Winnipeg’s south basin. The risk of shoreline ice pileup today is low on all assessed lakes.
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».