231:. The Flood of 2011 surpassed these totals, causing flooding to Lake Manitoba and peaked at 817.2 feet (249.1 m) above sea level, 5 feet (1.5 m) above the normal operating range . This led to flood fighting efforts shifting from the Assiniboine River to Lake Manitoba. A technical review of the 2011 flood completed in October, 2013 concluded that the net effect of artificial works (Fairford River improvements and the Portage Diversion) was a rise of 0.3 feet (0.091 m) on the lake. However, the rise occurred in weeks, rather than years as would occur in natural conditions.
217:
the increased capacity of the diversion and the duration of its use, it increased water levels on Lake
Manitoba significantly, more than the 1976 Assiniboine River Flood, which resulted in approximately 1,420,000 acre-feet (1.75 km) of water being diverted. In 2011 a total of 4,768,000 acre-feet (5.881 km) was diverted into the lake. The Manitoba Government's projections indicated that excluding the outflows of Lake Manitoba through the
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It was determined by the
Manitoba government that the capacity could be increased to 32000-34000 cu ft/s by building up the banks of the Portage Diversion, depending on hydraulic resistance on bridges along the channel. This would reduce the flows on the Assiniboine River somewhat, but still not
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With the diversion of water from the
Assiniboine using the Portage Diversion into Lake Manitoba, the water level on the lake increased. Increasing the capacity of the Diversion put surrounding residences in danger of being flooded, also prompting an evacuation of Delta Beach on Lake Manitoba. Due to
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as between the
Portage Diversion (34,000 cu ft/s (960 m/s)) and the Assiniboine River Channel (up to 20,000 cu ft/s (570 m/s)) could have handled the floodwater. The controlled breach has carried no more than 400 cu ft/s (11 m/s) and flooding was modest.
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15,000 cu ft/s (420 m/s), while over 800 homes would be affected by the waters. Military personnel were assigned to build flood protection in
Brandon, on the Assiniboine River west of Portage la Prairie, and for residences that were at risk of flooding due to the controlled breach.
119:
dikes. After a heavy snowfall on April 29 and 30 over much of the
Assiniboine River watershed the crest forecast for Brandon was revised upward well above the flood of 1976. The river peaked at about 36,700 cu ft/s (1,040 m/s),60% higher than the previous highest recorded peak of
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that flows through the city. The Souris River starts in
Saskatchewan and makes its way south across the border and then back north into Manitoba. The Souris River then eventually joins up with the Assiniboine River past Brandon which could again raise water levels on the Assiniboine due to the
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The intentional breach and overland flooding began on
Saturday May, 14. The resultant flooding was very slow moving and was expected to take several days to reach the La Salle River. The waters intentionally spilled from the Assiniboine were expected to cover 185 square kilometres
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The controlled breach of the dike was estimated to flood approximately 225 square kilometres (87 sq mi). This option was chosen as opposed to risking an uncontrolled breach, which could release as much as 500 square kilometres (190 sq mi) with flows of up to
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enough for the dikes to hold. It was also determined that a controlled release of water from the
Assiniboine in the range of 2000–6000 cu ft/s should be created downstream of the Portage Diversion in order to reduce flows on the river, and divert the water into the
111:. Dikes were built up to protect against the rising floodwater, but unfortunately some residences were not spared as their protective dikes were overwhelmed. The flood continued downstream, spilling over its banks and flooding campgrounds and fields in the flood plain.
182:
swollen Souris and the possibility of Lake
Manitoba raising up again. Preparations are under way for the communities along the Souris to raise dikes and evacuations have begun. The province has said it will push the limits of the flood protection again.
174:. This amount of water would overwhelm the dikes downstream, along the Assiniboine River, which were only built to allow for a channel capacity of about 10,000-11,000 cu ft/s before spilling over. Otherwise breaching of dikes would occur.
203:(71 sq mi) and flood a possible 150 homes. The Expected crest at the Portage Reservoir was then downgraded to around 52,000 cu ft/s (1,500 m/s), leading some engineers to question the necessity of the breach at
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was caused by above average precipitation in Western Manitoba and Saskatchewan. This was a 1 in 300 year flood that affected much of Western Manitoba. The flooding in Manitoba was expected to mostly involve the
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158:, is only approximately 25,000 cu ft/s (710 m/s), which would mean that between 29000-31000 cu ft/s of water would flow toward communities such as Poplar Point,
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The 2011 flood first began in the fall of 2010 with several major rainfall events and generally wet conditions. Initially, it was predicted that the flood along the
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troops from the Canadian military to help with the flood fighting efforts. The last time the military was called in to help fight a flood in Manitoba was the
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was emptied in preparation, to store water for the coming spring flood. With more and more precipitation, the estimates on the flood were revised upwards.
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watershed, resulting in more manageable river levels along the Assiniboine River. The exact location decided on was at the Hoop and Holler Bend.
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115:, Manitoba's second largest city, prepared well in advance of the anticipated flood building up both earthen dikes as well as sandbag/
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Downstream of Brandon, the Manitoba Government forecast that between 54000-56000 cu ft/s of water would enter into the
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Shortly thereafter a state of emergency was declared in Brandon as well as other municipalities across Manitoba. Premier
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23,000 cu ft/s (650 m/s) in 1923. The 2011 event is estimated to be a 1 in 300-year flood.
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https://www.gov.mb.ca/mit/floodinfo/floodproofing/reports/pdf/assiniboine_lakemb_lsm_report_nov2013.pdf
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On June 22, 2011 the city of Minot in North Dakota issued an evacuation of 12,000 residents due to the
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2011 Flood:Technical Review of Lake Manitoba, Lake St. Martin and Assiniboine River
367:"Quebec government poised to increase funding for flood-hit people and businesses"
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but instead the more severe flooding was found on the Assiniboine in the west.
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resulted in an increase of 1.22 feet (0.37 m) in the level of the lake
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would be similar to the flood of 1995. During the winter of 2010–2011 the
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348:"Evacuees wait to return home as Brandon faces one-in-300-year flood"
154:. The capacity for the Portage Diversion channel, which drains into
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which was located near the confluence of the Assiniboine River and
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328:"Brandon residents cope with state of emergency due to flooding"
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The first major settlement to experience the floodwater was
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249:"Man rescued from Assiniboine, another presumed drowned"
592:"Daily Water Levels and Forecasts for Manitoba Lakes"
432:. Government of Manitoba. May 9, 2011. Archived from
575:"Daily Water Levels and Forecasts – Manitoba Lakes"
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653:
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564:Calculated from Water Survey of Canada Data
514:"Province miscalculated flooding: engineer"
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475:"Water flows through Manitoba dike breach"
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387:"Provincial State of Emergency Declared"
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580:. Government of Manitoba. May 10, 2011.
463:. Government of Manitoba. May 10, 2011.
418:. Government of Manitoba. May 11, 2011.
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495:"Controlled spill slows river's rise"
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270:"Manitoba breach flooding downsized"
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13:
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365:St-Arnaud, Pierre (May 10, 2011).
127:Assiniboine River at Brandon Peaks
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301:. March 25, 2011. Archived from
292:"Media Bulletin – 25 March"
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247:Kevin Rollason (May 14, 2011).
186:Intentional breach and flooding
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135:requested from Prime Minister
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1:
677:Natural disasters in Manitoba
512:Bill Redekop (May 18, 2011).
395:. May 9, 2011. Archived from
268:Unattributed (May 15, 2011).
234:
662:2011 floods in North America
272:. United Press International
77:2011 Assiniboine River flood
35:2011 Assiniboine River flood
7:
10:
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599:Manitoba Water Stewardship
534:"Water Stewardship Report"
166:, before joining with the
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697:Westman Region, Manitoba
682:2011 disasters in Canada
212:Effects on Lake Manitoba
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205:Hoop & Holler Bend
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43:April 2011 – June 2011
29:considered for merging
227:May 28, 2016, at the
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461:"Flood Bulletin #41"
430:"Flood Bulletin #40"
416:"Flood Bulletin #43"
179:swollen Souris River
141:1997 Red River flood
105:St. Lazare, Manitoba
98:Shellmouth Reservoir
82:2011 Red River Flood
69:>$ 1 billion
634: /
519:Winnipeg Free Press
254:Winnipeg Free Press
160:St. Francois Xavier
36:
399:on March 31, 2012.
308:on October 4, 2011
152:Portage la Prairie
129:
34:
667:Assiniboine River
148:Portage Diversion
94:Assiniboine River
73:
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687:2011 in Manitoba
672:Floods in Canada
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601:. July 1, 2011.
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501:. May 15, 2011.
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483:. May 14, 2011.
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354:. May 10, 2011.
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336:. May 12, 2011.
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299:RM of Macdonald
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229:Wayback Machine
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150:reservoir near
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66:Property damage
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219:Fairford River
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193:La Salle River
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137:Stephen Harper
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638:49.6°N 99.5°W
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156:Lake Manitoba
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133:Greg Selinger
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117:Hesco bastion
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24:Infobox event
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548:. Retrieved
541:the original
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438:. Retrieved
434:the original
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397:the original
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352:CTV Winnipeg
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333:CTV Winnipeg
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310:. Retrieved
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643:49.6; -99.5
641: /
88:Early signs
18:‹ The
656:Categories
550:August 23,
440:August 23,
235:References
164:Headingley
172:The Forks
168:Red River
27:is being
499:CBC News
480:CBC News
225:Archived
52:Manitoba
48:Location
31:. ›
20:template
629:99°30′W
626:49°36′N
312:May 14,
276:May 16,
113:Brandon
162:, and
58:Deaths
595:(PDF)
578:(PDF)
544:(PDF)
537:(PDF)
306:(PDF)
295:(PDF)
552:2017
442:2017
392:CJOB
314:2011
278:2011
75:The
40:Date
170:at
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450:^
405:^
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369:.
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61:1
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