Strong north winds are forecast for today and tomorrow in the Lake Manitoba, Lake St. Martin, Shoal Lakes and Dauphin Lake area, resulting in significant wind set-up, wave action and flooding. Winds will be generally north up to 30 km/h until Sunday and then weaken and shift to the south by Monday.
Flood Response
There are three key areas of focus continuing in the Portage la Prairie area. The first is to strengthen the dikes between Portage la Prairie and Headingley, the second is to continue work at the Portage Diversion to manage additional flows, and finally, to continue preparations for the controlled release which is planned for early Saturday morning. This release will take pressure off the Assiniboine River dikes that protect communities between Portage la Prairie and Headingley.
Once the controlled release begins, there will be a flow of approximately 500 cubic feet per second (cfs), increasing to 1,000 cfs. This amount would be continually reassessed and modified as necessary. Based on the current forecast, the controlled release flows would then slowly increase to between 2,500 and 3,000 cfs over the following days. Heavy equipment is stationed around the spill to assist in managing the flow of water.
The flows entering the La Salle River watershed will disperse slowly across fields and then fill behind roads and spill at low points along roads. The overland flows will collect in two major tributaries of the La Salle River known as the Elm River channel and the Scott Coulee. The Elm River channel enters the La Salle system 3.2 kilometres south of Elie and the Scott Coulee enters the La Salle River eight km south and 3.2 km east of Elie.
Elie can expect water levels to affect the southern boundary of the community around two feet in depth (estimated). Given the limited level of topographic information, it is estimated that water will reach Elie in seven to eight days after the release is made. It is likely that flows from the controlled release will enter the La Salle River south of Elie, but water levels on the La Salle will be elevated due to water being pushed up the La Salle River channel. Water will reach the communities of La Salle, Sanford and Starbuck after this time, when it is anticipated that these communities will see reduced flows in the range of 1,500 to 2,500 cfs from the controlled release as water will be stored behind roads.
Flood-protection maps showing the impact of 4,000 cfs flows are available online for La Salle, Sanford and Starbuck. The maps show these communities will experience limited effects in most areas. The communities are actively putting in additional precautionary flood-protection measures.
Flows on the Assiniboine River into the Portage Reservoir have increased to 51,260 cfs from 50,700 cfs since yesterday. The Portage Diversion flow is 33,260 cfs at this time. Flow in the river downstream of Portage la Prairie is 18,000 cfs. The Portage Diversion is being monitored continually.
Provincial crews and hundreds of Canadian Forces continue to fortify dikes along the Assiniboine River. Helicopters are bringing sandbags into hard-to-reach areas and the dikes are being monitored and repaired on a 24-hour basis. The dikes are under heavy pressure from river flows and work is underway continuously to shore them up.
Sandbag machines are running in Portage la Prairie, St. Laurent, Crane River and Winnipeg to provide filled sandbags. The City of Winnipeg is also running two machines with hundreds of their employees to support flood-fighting efforts west of the city.
Approximately 80,000 sandbags are being sent to Lundar Beach and the RMs of Portage la Prairie and Siglunes.
Significant sandbagging efforts are underway at Dauphin Lake and at Twin Beaches on Lake Manitoba.
Brandon
In Brandon, hay bales are being put up against the dikes to protect against debris in the river and provide additional protection along 18th Street.
First Street remains closed and work is continuing to try and reopen the road.
In Brandon, there are 1,353 people evacuated.
Dikes are being closely monitored and reinforced as required.
Other areas
Dike construction is underway around Lake St. Martin to put flood-protection measures in place at the Lake St. Martin First Nation and the Little Saskatchewan First Nation.
In the Souris area, additional homes are setting up flood-protection measures due to rising waters on the Plum Creek. Flood-protection efforts are also underway to protect homes against rising waters near Oak Lake.
The dikes at St-Lazare have been successfully raised in areas of the community ring dike and sandbag dikes outside of the community.
The 42 residents of the St. Adolphe Personal Care Home who had evacuated on April 20 returned to the facility on Thursday.
The south closure on PTH 75 will open today to local traffic only to St. Jean Baptiste. PTH 75 north of Morris is still closed.
The south closure of the St. Adolphe ring dike opened yesterday, but the north closure remains in place.
An email has gone out to all government employees requesting volunteers who can work additional hours and assist with flood-fighting efforts. There are currently over 700 provincial government staff working on the flood response.
There are currently 3,329 Manitobans evacuated from their homes. People who have evacuated are encouraged to register at the reception centre or contact the Red Cross at 1-888-662-3211.
There are currently 115 provincial roads affected by flooding, with 72 closed. There are 770 municipal roads closed.
Assiniboine River
Water levels on the Shellmouth Reservoir are 1,414.38 ft., decreasing 0.09 ft. from yesterday. Inflow into the Shellmouth Reservoir is approximately 11,200 cfs. The Shellmouth Dam will be operated to maintain outflows below 12,000 cfs today and will be reduced to 11,500 cfs later today by reducing the conduit flow to 1,000 cfs. This operational plan will prevent Shellmouth outflows from further increasing crests downstream to Brandon and Portage la Prairie.
Water levels on the Qu’Appelle River at Welby decreased 0.19 ft. since yesterday to 18.25 ft. Flows on the Qu’Appelle reached 11,936 cfs yesterday.
St-Lazare’s water levels have increased 0.28 ft. since yesterday to 1,289.76 ft. St-Lazare’s community flood-protection level is 1,294.4 ft. and has been increased by approximately one foot.
Miniota’s water levels have increased 0.13 ft. since yesterday to 1,247.34 ft.
Water levels at Sioux Valley are 1,203.85 ft., decreasing 0.08 ft. since yesterday. Dikes at the Sioux Valley First Nation are providing flood protection to 1,207 ft.
Water levels on the Assiniboine River at the First Street Bridge in Brandon were 1,182.50 ft., decreasing 0.05 ft. since yesterday. Flows at the First Street Bridge in Brandon were 36,000 cfs, measured this morning.
Forecasters are estimating that flows may increase to 39,000 to 41,000 cfs and between 1,183.4 to 1,183.8 ft. at the First Street Bridge in Brandon between May 18 and 20. It is estimated that flows on the Assiniboine River at Brandon will be sustained for a long period of time.
Flows on the Assiniboine River at Holland are 52,700 cfs today.
There is currently more water being diverted through the Portage Diversion than what is currently flowing in the Red River floodway channel.
Water levels in the Baie St. Paul area have increased to 800.21 ft. Water levels in the Lido Plage area increased 0.07 ft. to 780.48 ft.
Red River
Water levels just upstream of the Red River floodway inlet decreased 0.26 ft. since yesterday to 763 ft., with flows of 66,900 cfs. Flows in the floodway were approximately 30,800 cfs.
Water levels on the Red River at James Avenue in Winnipeg have decreased 0.24 ft. since yesterday to 18.84 ft. Flows at James Avenue this morning were approximately 56,600 cfs.
Flows entering the La Salle River watershed from the controlled release will initially be low, then gradually increased to a range of 2,500 to 3,000 cfs. The La Salle River is a tributary which flows into the Red River downstream of the floodway inlet. It is anticipated that water level rises on the Red River would be as much as 1.5 ft. at James Avenue at the highest projected La Salle River inflow.
Should an uncontrolled breach occur on the south Assiniboine River dikes, as much as 15,000 cfs could flow into the La Salle River watershed.
Souris River
In response to recent precipitation, increased run-off in southeast Saskatchewan and near-capacity reservoirs, releases into the Souris River at Estevan, Sask., have increased, contributing approximately 7,300 cfs to the Souris River. These flows will take approximately four weeks to to reach Manitoba and are expected to extend the duration of high flows on the Souris River but are unlikely to increase water levels above what has been seen in previous peaks.
Water levels at Melita are 1,409.99 ft. today, decreasing 0.08 ft. since yesterday.
Water levels in Oak Lake are 1,412.17 ft. Water levels on Plum Creek have increased 0.85 ft. since yesterday to 1,377.52 ft.
The Souris River at Wawanesa is estimated to reach 16,000 cfs today with a water level of 1,156.43 ft. Forecasters have assessed the impacts of recent rains on the Souris River. The Souris River at Wawanesa may reach 16,000 cfs to 17,000 cfs between May 13 and 15.
Dauphin Lake, Swan Lake and Lake Winnipegosis Basins
Since yesterday, water level changes at tributaries in the Swan Lake, Dauphin Lake and Lake Winnipegosis basins include, the Roaring River decreased 0.73 ft., the Swan River decreased 1.08 ft., Wilson Creek decreased 2.06 ft., the Turtle River decreased 2.5 ft., the Ochre River decreased 1.57 ft.; and the Valley River increased 1.13 ft.
Lakes
Lake levels have reached or are approaching flood stage at many Manitoba lakes. Lakes above flood stage or are flooding due to persistent north winds include both basins of Lake Manitoba, Oak Lake, Lake St. Martin, Lake Pineimuta, Dauphin Lake, Lake Frances, North, East and West Shoal Lakes, Dennis Lake, Fish Lake and other lakes throughout the Interlake and southcentral part of Manitoba.
Due to these high water levels, Manitoba Water Stewardship has created inundation maps illustrating the forecast high water levels for many inhabited areas around Lake Manitoba. Two sets of maps will be available. Wind-eliminated and winds set-up maps for Alonsa, Lakeview, Siglunes, Coldwell, Portage la Prairie, Westbourne, Dog Creek First Nation, Sandy Bay First Nation, Woodlands, Eriksdale and St. Laurent.
Manitoba Water Stewardship is creating more maps for the Lake St. Martin and Lake Pineimuta area that will be made available as soon as possible.
For more information, please see www.manitoba.ca/flooding and find the most up-to-date highway information at www.gov.mb.ca/mit/roadinfo or 1-877-MBRoads (1-877-627-6237) and on Twitter by following @MBGov.
