Posted on 06/30/2011, 8:59 am, by mySteinbach

Progress is being made reinforcing flood protection along the Souris River by municipal and provincial staff. Some projects will be moving to a 24-hour operation. Motorists and the public are advised to be careful around workers and equipment.

The Village of Wawanesa has requested the City of Brandon to organize a 30-person sandbagging team for tomorrow and Friday, July 1.

There are also four five-member rapid-assistance teams in the RM of Coldwell to assist with sandbagging and dike construction efforts in the area today and tomorrow.

At this time are 2,979 Manitobans are evacuated.

Flood Forecast

Souris River

The U.S. National Weather Service (NWS) today increased the forecast peak flow at Westhope, N.D., to 30,142 cubic feet per second (cfs) on July 4, which is an increase of approximately

300 cfs since their June 27 forecast. A revised Souris River forecast has been developed to account for the increase in the U.S. NWS forecast peak.

The Souris River forecast, taking into consideration the June 29 Westhope forecast by the NWS, weather and flow conditions within Manitoba, is shown in the table below. The lower end of the forecast range was developed assuming favourable conditions, with no further rain, and the upper end of the forecast range was developed assuming unfavourable conditions of 25 to 30 millimetres of rainfall over saturated soils. The upper end of the forecast may change if additional rainfall is forecast.

Forecast flow, water level and date of occurrence were also developed for intermediate locations along the Souris River:

The Plum Creek at Souris decreased 0.25 ft. since yesterday to 1,374.19 ft. A flood warning for all reaches of Pipestone Creek and downstream into the Oak and Plum Lake system, then on Plum Creek to the Souris River including the town of Souris remains in effect.

Assiniboine River

The revised forecast was developed for the Assiniboine River due to the reduced crest seen on the Qu’Appelle River near Welby. The Assiniboine upstream of the Souris River is forecast to experience another peak in the beginning of July. The forecast peak flow, water level and date of occurrence for locations along the Assiniboine River:

Inflow upstream of Portage la Prairie is forecast to remain at or near the current flow of 38,000 cfs for the few couple days before it starts to rise in response to the large flows from the Souris River basin. The inflow into Portage la Prairie is forecast to reach 48,000 to 52,000 cfs between July 8 and 14, assuming a 2,000 cfs benefit from operating the Shellmouth Reservoir to hold more water. The lower end of the forecast range was developed for favourable conditions (no further rain) and the upper end of the forecast range was developed for unfavourable conditions and assumes 15 to 25 mm over saturated soils.

The Shellmouth Dam Liaison Committee supported an operation to reduce outflow by 500 cfs today and continue this daily reduction until July 2. Outflow will reach approximately 800 cfs on July 2 and remain at this level until July 6, when it will begin to rise by approximately 500 cfs per day to return to 3,200 cfs conduit outflow. This operation will reduce the peak flow upstream of Portage la Prairie by 1,500 to 2,000 cfs.

The Qu’Appelle River crested overnight at around 9,700 cfs which is earlier and of a lesser amount than the Saskatchewan Watershed Authority’s recent forecast crest of 11,500 cfs to occur on July 1.

Saskatchewan and Carrot Rivers

Water levels on the Saskatchewan River at The Pas increased 0.2 ft. since yesterday to 855.73 ft., with a flow of 74,500 cfs. The forecast range for The Pas remains at 858 to 859.3 ft. with the peak occurring between July 7 and 12. Flood proofing in the area is being built to accommodate this level of high water.

Forecast peak water levels on the Carrot River are being reassessed.

Wind Set-up Alerts

Environment Canada has issued a strong wind warning for Lake Manitoba, Lake Winnipeg and Lake Winnipegosis. Winds on Lake Manitoba will be southeast 37 km/h today, changing to south 27 km/h tomorrow morning and switching direction to west 27 km/h in the afternoon, then increasing to west 37 km/h for Friday. Winds on the south basin of Lake Winnipeg are south 37 km/h today and will remain there until tomorrow evening when they change to southwest 27 km/h, then change to west 37 km/h for Friday. Winds on Lake Winnipegosis are south 37 km/h today, decreasing to southeast 27 km/h overnight and changing direction to southwest 27 km/h by tomorrow morning before becoming light in the evening, then increasing to west 27 km/h by Friday afternoon.

Wind set-up alerts for today include:

• A high wind set-up for the north shore of Lake Manitoba. This includes communities such as Homebrook, Davis Point and St. Martin.
• A moderate wind set-up for the west shore and east shore of Lake Manitoba, the northwest shore of Lake St. Martin and the west shore of the South Basin of Lake Winnipeg. This includes communities such as Sandy Bay, Meadow Portage, Crane River, St. Laurent, Lundar Beach, Vogar, the Lake St. Martin First Nation, the Little Saskatchewan First Nation and Gimli.

Wind set-up alerts forecast tomorrow include:

• A moderate alert for the west shore of the northern basin, through the Narrows, the east shore, and the southeast corner of Lake Manitoba, and the west shore of the South Basin of Lake Winnipeg. This includes communities such as Meadow Portage, Crane River, Twin Lakes Beach, St. Laurent, Lundar Beach, Steeprock and Gimli.

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