April 5, 2011
Flood Bulletin #2
Weather and Effect on River Conditions
- Very little or no precipitation has been reported in southern Manitoba in the last 24 hours. The weekend storm brought wet snow and rain amounting to five to 23 millimetres (0.2 to 0.9 inches) in southern Manitoba. Both Pansy and Portage received 23 mm (0.9 in.) while Emerson had 13 mm (0.5 in.) and Winnipeg saw 10 mm (0.4 in.).
- The precipitation was less in the U.S. portions of the Red River with many areas receiving less than five mm (0.2 in.) and only a few areas receiving up to 15 mm (0.6 in.). The storm had little impact on river levels and only resulted in minor flow increase.
- The weather forecast calls for sunny periods mixed with clouds and a chance of precipitation with amounts of up to 10 mm (0.4 in.) on Thursday and Friday in portions of Manitoba. Temperatures will rise gradually to an average of 5 C by the weekend. Temperature forecasts for the next two weeks indicate very gradual rises with temperatures remaining above freezing and slightly higher than normal.
- Due to the recent mild weather and rains, rivers and streams are beginning to flow. Most streams and rivers remain well within their banks but levels are expected to rise gradually as the temperatures begin to warm up. The rate of increases in river and streams will depend on the weather conditions, especially temperature changes and future precipitation amounts.
- Overland run-off has started to cause flooding of agricultural land. However, freezing culverts are not causing as much flooding as in previous years, such as experienced in 2009.
Red River
- The U.S. portion of the Red River between Fargo and Pembina has risen by 0.5 to 0.6 metres (1.5 to two feet) in the last 24 hours. Many locations are either close to or above the flood stage level.
- The Red River at Pembina just upstream of Emerson is under the flood stage by about 0.8 m (2.7 ft.)
- Red River tributaries in Manitoba have risen by up to 0.15 to 0.6 m (0.5 to two ft.) in the last 24 hours. The LaSalle and Morris rivers rose by about 0.3 m (one ft.), while the Seine River rose by nearly 0.6 m (two ft.).
- The river level at Emerson has increased by more than 0.8 m (2.5 ft.) to a level of 236.9 m (777.53 ft.) since yesterday. The flow this morning was 26,000 cubic feet per second (cfs) and well within riverbanks. The flood stage level at Emerson is 238.7 m (783.2 ft.) and the dike elevation is 242 m (794.0 ft.). At Ste. Agathe, the flow is 30,000 cfs.
- Red River at James Avenue stood at 4.6 m (14.97 ft.) this morning after rising 0.3 m (one ft.) since yesterday. The flow is 34,000 cfs. The natural flow into the floodway is 2,000 cfs and the water elevation at the floodway is 228.9 m (751.31 ft.). The floodway gates have not yet been operated.
- At Selkirk, the flow is 38,000 cfs. An ice jam that was reported at Lockport has moved downstream, south of Selkirk Golf Course. So far, there have been fewer ice jams than in previous years and they have caused minimal flooding.
- Based on predicted peaks on the U.S. portions of the Red River, the estimated crest could be late April to early May at Emerson. Arrival time in Winnipeg could be in the first week to early in the second week of May. The crest magnitude will be calculated as weather and river conditions evolve and will be made available as soon as it is determined.
Assiniboine River
- The Assiniboine River has experienced only slight rises as tributaries start reacting to recent warmer temperatures. Water levels have risen by no more than 0.15 m (0.5 ft.).
- Miniota has seen a rise of nearly 0.06 m (0.2 ft.) since yesterday, while Headingley went up by three centimetres (1.2 in.). The flow at Headingley was 2,750 cfs this morning.
- This morning, the Shellmouth Dam inflow was 410 cfs and outflow was 400 cfs. The reservoir level is being maintained at a winter drawdown level of 421.8 m (1,383.8 ft.) until significant snow melts in the watershed.
Pembina River
- There have been only slight water level rises of about less than 1.2 in. (3.05 cm).
Saskatchewan River at The Pas.
- Minimal rises of less than 0.09 m (0.3 ft.) have occurred in the last 24 hours.
Souris River
- The Souris River at Souris has risen by 0.03 to 0.09 m (0.1 to 0.3 ft.) on the Manitoban side. Significant water is flowing from U.S. tributaries due to high moisture levels in the upper Souris watershed.
- Some locations in the U.S. are at flood or above flood stage including Westhope.
Interlake
- The Fisher River has experienced little change since yesterday and no major river levels have been reported in the last 24 hours.
Other Rivers and Lakes
- Generally, minimal changes have occurred in the last 24 hours.
River Ice Conditions
- Active snowmelt and river ice breakup is underway on the Red River as average temperatures rise above freezing point. Note that some locations in the Red and Assiniboine rivers have thin ice due to high water and some ice movement has been reported in Lockport. It is difficult to predict where ice jams will occur.
Flood Preparation and Response
- Work on the Assiniboine dikes is almost complete with some cleanup now taking place.
- Work on the ring dike at Lowe Farm is close to completion and work is progressing on the ring dike at Letellier.
- Amphibex machines will be pre-positioned north of Winnipeg along the Red River and near Portage la Prairie. The third machine will be positioned as needed to break up ice.
- Municipalities are ready and continuing to maintain close contact with Manitoba Emergency Measures Organization and other provincial government departments. The $22 million in new equipment including steamers, flood tubes, rapid response trailers, pumps, cage barriers and related equipment is in place and positioned around the province to respond.
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