April 19, 2006
Weather
A slow-moving storm system over the United States dropped 40 to 50 mm of precipitation on eastern Saskatchewan yesterday, with some areas receiving heavy snow. Areas of western Manitoba from the U.S. border to The Pas received 10 to 30 mm of rain. The Red River Valley in Manitoba and the United States received five to 10 mm of rain. Some additional showers may occur in the next few days as the system weakens, but little precipitation is expected in Manitoba from now through the weekend.
The greatest impact of the rain will be felt in the Assiniboine River watershed where additional releases from Shellmouth Reservoir will be necessary to accommodate increased run-off from rains in Saskatchewan. These releases, combined with rising tributary flows downstream of the reservoir, may cause flooding of agricultural valley lands from Shellmouth to Brandon during the next few weeks.
However, this flooding will not exceed what would have been the natural peak flooding level experienced in the absence of the reservoir. It is expected that no dwellings or other infrastructure will be flooded. This operation will provide some ability to protect agricultural lands and allow seeding to take place earlier.
Operation of the Portage Diversion will prevent flooding from Portage la Prairie to Winnipeg.
Red River
The Red River is very near its crest at all Manitoba points. Additional rises of about one inch have occurred from Morris to Ste. Agathe since yesterday morning. Some of these rises may be due to wind effects over the flooded area south of Morris. A further rise of 0.1 feet may occur at Ste. Agathe, otherwise levels should remain steady for the next few days.
The river has declined 0.2 feet at Emerson since yesterday morning and will begin to decline slowly in the Morris area toward the end of this week. It will be 10 to 12 days until major roads in the flooded area will emerge.
The Red River level in downtown Winnipeg this morning was 18.33 feet, a very slight rise since yesterday. Levels in the city are expected to remain between 17.5 and 18.5 feet for the next two weeks.
The flow in the Red River Floodway this morning was 32,600 cubic feet per second (cfs) while the flow upstream of the floodway inlet was 78,500 cfs.
Assiniboine River
The Assiniboine River is presently within its banks at all points due to operation of flood control structures.
Run-off from yesterday’s rain and snow will cause significant rises in the river during the next few weeks.
Because of increased run-off from rains in Saskatchewan, flooding of agricultural valley lands from Shellmouth to Brandon will occur during the next few weeks. This is due to the increased inflows to the reservoir and rising tributary flows downstream of the dam. Flooding is not expected at Brandon with the possible exception of low-lying areas at Curren Park.
Outflows from Shellmouth Reservoir will be increased to prevent uncontrolled spillway overflows from occurring. An operation plan is being formulated in collaboration with the Shellmouth Reservoir Regulation Liaison Committee, which includes stakeholders along the river.
The flow in the Portage Diversion this morning was 5,000 cfs while the inflow to Portage Reservoir was near 10,500 cfs.
Flooding of low-lying agricultural lands has developed along the Shell River in the Roblin area and will continue for several weeks. Flooding of low-lying areas in the river valley could also occur in the Inglis area, beginning later this week.
Souris River
Minor flooding of farmlands in the Souris River valley from Coulter to Melita will continue for two to three weeks. The river has crested at Melita, but a minor rise may occur next week due to yesterday’s storm.
Pembina River
Significant flooding continues on the Pembina River from Rock Lake to Windygates, but levels will continue to decline.
Water levels at the Aux Marais crossing at the international boundary have stabilized and wave action will be further reduced due to winds shifting to the north tomorrow.
Whitemud and Turtle Rivers
Some flooding continues along the Whitemud River in the Woodside area and near the Big Grass Marsh. Levels will fall very slowly during the next two weeks.
Carrot and Saskatchewan Rivers
Levels of the Saskatchewan River at The Pas have changed little from yesterday, but may rise later this week due to increased flows coming from Saskatchewan and some local run-off from rainfall. The second crest, which is expected between April 24 and April 26, should be lower than last Saturday’s crest.
Levels in the Carrot River west of The Pas have begun to rises as more water arrives from Saskatchewan. There is no change in the forecast with a crest still expected between April 23 and April 25. There will be flooding of some farmland near the river and a few homes may require diking.
High levels on Grace Lake continue near The Pas, but water is being controlled by an emergency dike.
Agricultural lands in the Pasquia River Valley near The Pas have been flooded and pumping continues to reduce levels.
Swan and Red Deer Rivers
The river level at Swan River continues to decline slowly. A minor second crest may occur at Swan River late this week because of the rain, but it will be lower than the first crest and should not cause flooding in town.
The Red Deer River continues to rise at Erwood in eastern Saskatchewan and will reach levels several feet higher than previous crests in Manitoba during the next few days. The crest is expected in Manitoba this weekend. Landowners along the river are advised to take appropriate actions to protect property.
The Red Deer Lake has risen 2.8 feet and has now reached the previous record high level set in 1979. It is expected to rise a foot further with a crest during the middle of next week. The community of Red Deer Lake is diking low-lying homes to protect against the rise plus possible wave action.
Other Central and Northern Manitoba Waterways
Most streams flowing off the Riding and Duck mountains and the Porcupine Hills have risen due to yesterday’s rain but are expected to remain well within their banks. Larger streams in the area, such as the Shell and Little Saskatchewan rivers are still rising and will experience some flooding from now through next week.
Boating Safety
All operators of boats and personal watercraft should avoid flooded rivers and streams in Manitoba. Unpredictable currents, floating debris and submerged obstacles make flooded waterways unsafe for boating.
There are restrictions to navigation caused by the operation of the floodway gates south of Winnipeg as well as the potential for turbulent waters at or near the outlet structure north of Winnipeg. Caution should be exercised at all provincial water control structures.
Road Closures
PTH 23 just west of Morris is closed to all traffic. The road is signed and marked.
PTH 75 remains closed from the Perimeter Highway at Winnipeg to PTH 14 south of Morris. Alternate route detours for truck and through vehicle traffic travelling to U.S. I-29 is available online at http://www.gov.mb.ca/tgs/hwyinfo/2006floodstage1.pdf.
Many provincial highways and roads in southeastern Manitoba are currently affected by overland flooding. Motorists are advised to check road conditions before travelling.
Road closure information is updated 24 hours a day and posted on the provincial website at http://www.gov.mb.ca/roadinfo or by calling 204-945-3704 or 1-877-MBRoads (1-877-627-6237).
General Information
People who live in flooded areas and rely on well water will be able to have water quality tested at no charge. As a precautionary measure, the Office of the Chief Medical Officer of Health for Manitoba advises that all people using water from wells or other sources that may be affected by flooding should boil their water before using it or find alternative supplies of drinking water until flooding subsides.
For further information, visit http://www.gov.mb.ca/flood.
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