Editing Lake Manitoba (section)

===Historical floods===
Unlike a river which can rise and recede relatively quickly, large lakes like Lake Manitoba require months or even years for lake levels to rise and fall. Below are the flood years on record in which Lake Manitoba was above flood stage, as defined by Manitoba Infrastructure and Transportation (MIT), of {{convert|814|ft|order=flip|abbr=on}} ASL. However, beginning around a level of {{convert|813|ft|order=flip|abbr=on}} ASL, localized flooding of agricultural land around the lake can occur.<ref>{{cite web|title=Provincial Flood Control Infrastructure Review of Operating Guidelines: A Report to the Minister of Manitoba Infrastructure and Transportation|url=https://www.gov.mb.ca/mit/wms/wm/pdf/review_operating_guidelines.pdf|publisher=Province of Manitoba|date=August 2015|page=55|access-date=April 24, 2017}}</ref>

{| class="wikitable"
|-
! Year(s)
! Peak lake level (ASL)
|-
! 2011-12
| {{convert|817.2|ft|order=flip|abbr=on}} (2011)<ref>{{cite web|title=Lake Manitoba and Lake St. Martin Outlet Channels Conceptual Design Preliminary Options|url=https://www.gov.mb.ca/mit/floodinfo/floodproofing/reports/pdf/lmb_lsm_outlet_channel_storyboards.pdf|publisher=Province of Manitoba|date=2014|page=17|access-date=April 23, 2017}}</ref>
|-
! 1881-82
| > {{convert|817|ft|order=flip|abbr=on}} (1882)<ref>{{cite web|title=2011 Flood: Technical Review of Lake Manitoba, Lake St. Martin and Assiniboine River Water Levels|url=https://www.gov.mb.ca/mit/floodinfo/floodproofing/reports/pdf/assiniboine_lakemb_lsm_report_nov2013.pdf|publisher=Province of Manitoba|date=October 2013|page=40|access-date=April 23, 2017}}</ref>
|-
! 1954-57
| {{convert|816.6|ft|order=flip|abbr=on}} (1955)<ref>{{cite web|title=2011 Flood: Technical Review of Lake Manitoba, Lake St. Martin and Assiniboine River Water Levels|url=https://www.gov.mb.ca/mit/floodinfo/floodproofing/reports/pdf/assiniboine_lakemb_lsm_report_nov2013.pdf|publisher=Province of Manitoba|date=October 2013|page=25|access-date=April 23, 2017}}</ref>
|-
! 1913
| > {{convert|816|ft|order=flip|abbr=on}}<ref>{{cite web|title=Provincial Flood Control Infrastructure Review of Operating Guidelines: A Report to the Minister of Manitoba Infrastructure and Transportation|url=https://www.gov.mb.ca/mit/wms/wm/pdf/review_operating_guidelines.pdf|publisher=Province of Manitoba|date=August 2015|page=52|access-date=April 24, 2017}}</ref>
|-
! 2014
| {{convert|814.7|ft|order=flip|abbr=on}}<ref>{{cite web|title=Provincial Flood Control Infrastructure Review of Operating Guidelines: A Report to the Minister of Manitoba Infrastructure and Transportation|url=https://www.gov.mb.ca/mit/wms/wm/pdf/review_operating_guidelines.pdf|publisher=Province of Manitoba|date=August 2015|page=23|access-date=April 23, 2017}}</ref>
|-
! 1924
| {{convert|814.2|ft|order=flip|abbr=on}}<ref>{{cite web|title=Lake Manitoba and Lake St. Martin Outlet Channels Conceptual Design Preliminary Options|url=https://www.gov.mb.ca/mit/floodinfo/floodproofing/reports/pdf/lmb_lsm_outlet_channel_storyboards.pdf|publisher=Province of Manitoba|date=2014|page=4|access-date=April 24, 2017}}</ref>
|-
! 1925
| {{convert|814.2|ft|order=flip|abbr=on}}<ref>{{cite web|title=Lake Manitoba and Lake St. Martin Outlet Channels Conceptual Design Preliminary Options|url=https://www.gov.mb.ca/mit/floodinfo/floodproofing/reports/pdf/lmb_lsm_outlet_channel_storyboards.pdf|publisher=Province of Manitoba|date=2014|page=4|access-date=April 23, 2017}}</ref>
|}

*In 1881-82 lake levels were not recorded. However, given the topography around Lake Manitoba, a level of {{convert|817|ft|order=flip|abbr=on}} ASL would be required to cause the lake to drain back into the Assiniboine River, which occurred in both 1881 and 1882. Also, a flow of {{convert|14,835|cuft/s|m3/s|order=flip|abbr=on}} was recorded on the Fairford River in 1881, long before significant channel improvements were made. Based on a rating curve for flows on the Fairford River during this period, the flows correlate with a lake level as high as {{convert|817.5|ft|order=flip|abbr=on}} ASL. Furthermore, in his 1890 study entitled "Report of Exploration of the Glacial Lake Agassiz in Manitoba", Warren Upham states that Lake Manitoba rose approximately {{convert|8|ft|order=flip|abbr=on}} above its lowest level, which records show to be around {{convert|810|ft|order=flip|abbr=on}} ASL, suggesting a peak of {{convert|818|ft|order=flip|abbr=on}} ASL.<ref>{{cite web|title=2011 Flood: Technical Review of Lake Manitoba, Lake St. Martin and Assiniboine River Water Levels|url=https://www.gov.mb.ca/mit/floodinfo/floodproofing/reports/pdf/assiniboine_lakemb_lsm_report_nov2013.pdf|publisher=Province of Manitoba|date=October 2013|page=40|access-date=April 23, 2017}}</ref>
*Lake Levels did not begin to be recorded until 1914. However, in 1913 a flow rate of {{convert|11,500|cuft/s|m3/s|order=flip|abbr=on}} on the Fairford River was recorded, which based on a rating curve for flows during this period would correspond with a lake level of greater than {{convert|816|ft|order=flip|abbr=on}} ASL.<ref>{{cite web|title=Provincial Flood Control Infrastructure Review of Operating Guidelines: A Report to the Minister of Manitoba Infrastructure and Transportation|url=https://www.gov.mb.ca/mit/wms/wm/pdf/review_operating_guidelines.pdf|publisher=Province of Manitoba|date=August 2015|page=52|access-date=April 24, 2017}}</ref>
*On May 31, 2011, during a major wind event, Lake Manitoba was measured at {{convert|820.37|ft|order=flip|abbr=on}} ASL at Twin Lakes Beach.<ref>{{cite web|title=Flood Bulletin #68 - June 3, 2011|url=http://news.gov.mb.ca/news/index.html?archive=today&item=11676|newspaper=Province of Manitoba|date=June 3, 2011|access-date=April 23, 2017}}</ref> As a result of the high water level with wind set-up and wave action, significant damage occurred along the south basin of Lake Manitoba. The 2011 peak flood level is the wind-eliminated peak lake level.