Preparations and analysis work continues as a fifth heavy storm threatens to dump additional rain on parts of Manitoba already soaked by floodwaters and four recent rain storms. The storm and its potential impact are being assessed on an ongoing basis.
Decisions about additional flood-protection efforts, including protection that would be required for a possible reopening of the controlled release point at the Hoop and Holler Bend, will be assessed throughout the weekend as more information about the incoming storm becomes available.
Forecast rains for early next week may bring up to 30 millimetres of rain to the Souris and Assiniboine river basins. In May, the Souris River basin has received almost 300 per cent of normal precipitation and areas of the Assiniboine River basin received between 150 and 250 per cent of normal. The maps at www.manitoba.ca/flood show precipitation levels experienced this spring.
On May 18, the Assiniboine River crested at the Portage Reservoir and reached a peak inflow of 52,300 cubic feet per second (cfs). After this peak, flows declined 18,480 cfs to a flow of 33,820 cfs on June 2. Recent storms have increased flows and with this most recent rain, flows on the Assiniboine River at the Portage Reservoir increased 11,400 cfs.
As a result of the next forecast storm, flows into the Portage Reservoir are forecast to reach between 51,000 and 53,000 cfs, depending on future weather.
To manage these flows, the Portage Diversion is expected to run over its design capacity to 34,000 cfs or higher.
Since March, ongoing work has strengthened the Assiniboine River dikes and they are in better condition now than during the May 18 crest that resulted in a controlled release at the Hoop and Holler Bend. The Assiniboine River dikes are being continuously monitored and reinforced to accommodate increased flows.
All efforts will be made to keep Assiniboine River flows in both the diversion channel and the Assiniboine River.
Evacuation alerts have been issued to 45 residences around the diversion channel.
To the east, Winnipeg, Steinbach, St. Anne, Morris and Lac du Bonnet are forecast to receive up to 70 mm of precipitation between June 12 and 15, primarily on Sunday and Tuesday. Soils are not completely saturated in the region east of Winnipeg and may be able to absorb some of the moisture from the forecast rain event on Sunday. Soils may then become saturated and any additional precipitation wiould result in increased run-off. Winds are forecast to be from the south and generally less than 30 km/h for the next few days.
Other Areas
The Town of Souris has declared a state of local emergency due rising water levels on the Souris River. A mandatory evacuation of 22 homes occurred yesterday and an additional 17 homes have been put on a voluntary evacuation order as water has risen against a dirt and sandbag dike. Additional sandbagging is underway to reinforce existing dikes.
Work is underway to shore up the Wawanesa dam using two helicopters to place heavy rock around the structure.
Whitemud River levels are high due to the most recent storm and there is some flooding around Woodside and Westbourne. Some access roads in the area around the community of Woodside are currently under water.
The Manitoba Emergency Measures Organization mobile command centre will be in St-Lazare today, in Deloraine tomorrow and in Glenboro on June 12 to answer questions and take applications for disaster financial assistance (DFA).
Construction and reinforcement of the Ralls Island dike is progressing well. High flows are expected along the Saskatchewan River early next week.
There are currently 2,238 Manitobans evacuated from their homes.
Flood Forecast Summary
A revised forecast has been developed for the Souris River:
• Melita is forecast to reach between 1,411.6 and 1,412.0 ft. by June 16 and 17.
• At the town of Souris, the river is near peak at 1,360.78 ft.
• Wawanesa is forecast to reach between 1,159.2 and 1,160.2 ft. by June 11 and 12.
Lake Manitoba water levels are forecast to reach between 816.8 and 817 feet around mid-July. Lake St. Martin water levels are forecast to reach between 806 and 806.2 ft. around early August, weather dependent.
Wind set-up alerts for today include:
• A high wind set-up alert for the north shore of Lake Manitoba’s North Basin. This includes residents south of PR 328.
• A moderate wind set-up alert for the east and west shores of Lake Manitoba’s North Basin, the east shore of Lake Manitoba’s South Basin, the west shore of Lake Winnipeg’s South Basin, and Oak Lake northeast shores. This includes communities such as Gimli, Dunnottar, Winnipeg Beach, Lundar Beach, Oak Point and Steeprock.
Water levels on the Whitemud River are expected to rise as a result of recent rains. Water levels near Keyes increased 1.44 ft. since yesterday to 953.34 ft. Water levels on Oak Lake remain very high. Water continues to flow over the dikes around part of the lake.
Water levels on the Little Saskatchewan and Oak rivers are now declining at all points including Rivers and Minnedosa reservoirs.
Water levels on the Saskatchewan River near The Pas are expected to reach 855.5 to 857 ft., depending on the weather.
Water levels on Rock Lake declined 0.16 ft. since yesterday to their current level of 1,336.51 ft. The outlet at Pelican Lake has been operating at full capacity since June 5.
The estimated outflow from the Fairford River water control structure is 18,900 cfs today. Today’s flow is the highest on record. The structure continues to operate at full capacity due to the high level of Lake Manitoba.
Water levels on the Saskatchewan River at The Pas increased 0.1 ft. since yesterday to
853.64 ft., with a flow of 64,000 cfs.
Water levels on the Saskatchewan River near The Pas are expected to reach 855.5 to 857 ft. by late June, depending on the weather. The reinforcement of existing dikes and the building of permanent dikes are underway.
Assiniboine River
The flood warning for the Qu’Appelle River in the St-Lazare area remains in effect. Water levels on the Qu’Appelle River at Welby are 16.2 ft. today, decreasing 0.3 ft. since yesterday.
Water levels on the Shellmouth Reservoir are 1,407.9 ft., decreasing 0.15 ft. since yesterday. Inflow into the Shellmouth Reservoir is 2,800 cfs and outflow is 3,900 cfs today.
Operations at the Shellmouth Reservoir will be adjusted over the next few days so conduit outflows equal reservoir inflows. When this is achieved, the water elevation on the reservoir will be static. This operation will help reduce Portage Diversion inflow to account for future weather conditions.
Water levels on the Assiniboine River at the First Street Bridge in Brandon are at 1,179.78 ft., decreasing 0.25 ft. since yesterday. Flows at the First Street Bridge are estimated to be
24,900 cfs.
Inflow upstream of Portage la Prairie is 48,300 cfs. Flows in the Portage Diversion channel are 30,350 cfs. Flows on the Assiniboine River at the Portage Reservoir control gates are 17,950 cfs.
Water levels in the Baie St. Paul area are 799.98 ft., no change since yesterday.
The flood warning for the Assiniboine River at all points downstream of the Shellmouth Dam remains in effect.
Souris River
Forecast rains for early next week may bring up to 30 mm of rain to the Souris River basin.
The flood warning for the Souris River remains in effect.
Plum Creek decreased 0.05 ft. since yesterday to 1,376.76 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.
Water levels on the Souris River at Melita are 1,411.34 ft., Souris is at 1,360.769 ft. and at Wawanesa 1,158.79 ft. Flows on the Souris River at Wawanesa are estimated to be 20,200 cfs today.
