Manitoba Water Stewardship

FLOOD UPDATE FOR MANITOBA

April 30, 2006.

Flood sheets showing present conditions and an updated forecast for: Red River, Pembina River, Assiniboine River and Swan River - The Pas Area are attached.

Weather

Unsettled weather with scattered showers is expected over Manitoba for the next five days. Rainfall amounts are expected to be relatively light and unlikely to affect river levels significantly.

Red River

Levels of the Red River declined about one foot at most points from Emerson to the Floodway Inlet during the 24 hour period ending this morning. Levels will continue to decline a little faster day by day based on little precipitation.

As a result of dry weather and relatively rapid river declines this week, PTH 75 re-opened late last Friday afternoon. The highway had been closed to traffic just north of Morris since April 10th. The flooded area in the Red River Valley is rapidly shrinking and the river should be back within its banks before the end of this week.

The Red River level in downtown Winnipeg this morning was 17.3 feet, a decline of about 0.2 feet since yesterday and a decline of three feet from the crest of April 7. Levels in the city will continue to decline slowly based on favourable weather. However it will take several weeks with little precipitation before levels in the City return close to normal. The natural level in downtown Winnipeg today without operation of flood control works would have been 24.1 feet.

The flow in the Red River Floodway this morning was 18,840 cubic feet per second (cfs) while the flow upstream of the floodway inlet was 64,280 cfs. Flows into the Floodway at St. Norbert should decrease to near zero by the end of this week based on favourable weather.

Assiniboine River

The Assiniboine River is still within its banks from Oak Lake to Winnipeg due to operation of flood control works. Extensive flooding of valley lands continues from Shellmouth Dam to Millwood and minor overbank flows are occurring from St. Lazare to Virden. Levels from Miniota to Virden have been relatively steady in recent days but will begin to rise again this week as higher flows arrive from the Shellmouth area. Increases in river levels will spread downstream to Oak Lake and Brandon by the end of the week, causing a shallow inundation of agricultural lands in the river valley. Flooding from St. Lazare to Grand Valley should end by the third week of May with normal weather conditions.

Flooding from Shellmouth to Millwood will more extensive than at downstream points and will last about one week longer due to the smaller channel capacity.

The water level in Shellmouth Reservoir this morning was 1412.0 feet, which is 3.5 feet above the spillway elevation. The reservoir inflow was 6600 cfs, a decline of 800 cfs from yesterday morning. The total outflow was 4850 cfs, of which 4500 cfs was going over the spillway. Flow through the conduit was further reduced to 350 cfs yesterday evening to prevent the total outflow from exceeding 5,000 cfs. It will be reduced to zero later today. The reservoir water level is expected to crest at 1412.2 feet on May 2 based on little precipitation and light winds.

Manitoba Water Stewardship, in consultation with the Shellmouth Reservoir Regulation Liaison Committee, is operating the reservoir to minimize the peak outflow. Controlled conduit outflows have been reduced about three times each day to achieve this. Reservoir and river conditions as well as inflow forecasts are reviewed frequently each day.

Flooding is not expected in Brandon with the possible exception of low lying areas at Curren Park. Locations from Brandon to Winnipeg will experience only minor rises as the river remains well within the banks.

The flow in the Portage Diversion this morning was 3,830 cfs while the inflow to Portage Reservoir was near 9,030 cfs. It is expected that flows in the Portage la Prairie are will change little in the next few weeks based on normal weather conditions.

Flooding of low-lying agricultural lands along the Shell River will continue for another week or so even with favourable weather.

Pembina River

Significant flooding continues on the Pembina River from Rock Lake to Swan Lake, but levels continue to decline.

Water levels at Gretna and at the Aux Marais crossing at the international boundary fell one-third of a foot since yesterday.

Carrot and Saskatchewan Rivers

The level of the Saskatchewan River at The Pas continues to decline very slowly and no further rise is expected with favourable weather.

Levels of the Carrot River from the Saskatchewan boundary to 12 miles west The Pas changed little in the past 24 hours as the river essentially at its crest. Minor flooding has developed in this portion of the river and a few residents are pumping water from their yards. Levels will remain high for the next 2-3 weeks. Levels within 5 miles of The Pas will continue to decline slowly based on little precipitation.

Extensive flooding of agricultural lands in the Pasquia River Valley near The Pas continues with levels in some areas as high as those of the flood last autumn. Pumping to reduce water levels continues at maximum capacity.

Red Deer River

The Red Deer River crested early this week in the Manitoba portion upstream of Red Deer Lake. Long-term residents say that this flood is greater than that of 1955.

The level of Red Deer Lake declined a tenth of a foot since yesterday and is still three feet higher than the crest of 1979. Residents of the community of Red Deer Lake will need to remain relocated for a considerable period of time since it will take 3-4 weeks before levels decline sufficiently for the clean-up to commence.

Hydrologic Forecast Centre,
Water Branch,
Manitoba Water Stewardship

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Water Information

FLOOD UPDATE FOR MANITOBA