Sumas Prairie Explained

Sumas Prairie is a landform in British Columbia, Canada and the State of Washington, United States. Part of the Fraser Lowland, it was created by the draining of Sumas Lake early in the 20th Century, and extends from the Vedder Canal southwestwards into northern Whatcom County, Washington.[1] The British Columbia Highway 1 traverses the former lakebed on the prairie between Abbotsford and Chilliwack.[2]

All of its Canadian portion, except its northeasternmost area around Yarrow, which is part of today's City of Chilliwack, was formerly the District of Sumas, which was amalgamated into the District of Abbotsford in 1972.[3]

thumb|800px|center|View of Sumas Prairie from Lower Sumas Mountain, Abbotsford.

Flooding

Since the draining of the lake, Sumas Prairie has periodically flooded during major spring freshets of the Fraser River, occurring in 1894, 1948, 1972, and 2007. The prairie has also flooded due to extreme rainfall events, occurring in November 1990[4] [5] [6] [7] and November 2021. During the 2021 British Columbia and Washington floods, the Sumas Prairie flooded, forcing evacuation of 1100 homes.[8] Floodwaters came from the Nooksack River in neighboring Washington State, which usually flows towards Bellingham Bay.[9]

On November 19, 2021, Abbotsford mayor Henry Braun announced that the Canadian Army would build a levee to replace a broken dike and prevent the Sumas Prairie from further flooding. He said that this would lead to the flooding of about a dozen homes, but this was the only available option to prevent even more flooding.[10]

See also

References

49.05°N -122.1333°W

Notes and References

  1. https://apps.gov.bc.ca/pub/bcgnws/names/13332.html BCGNIS entry "Sumas Prairie"
  2. Web site: What is Sumas Lake? 100 years ago, Abbotsford had a 134 sq km lake (PHOTOS) Urbanized. 2021-11-18. dailyhive.com. en.
  3. https://apps.gov.bc.ca/pub/bcgnws/names/41490.html BCGNIS entry "Sumas (district municipality)"
  4. Web site: The Fraser River doesn’t pose the only flood threat to Abbotsford. The Abbotsford News. A Nooksack flood in 1990 swamped the Whatcom Road interchange and western portions of Sumas Prairie. Such a flood is expected to take place every 35 years or so. There are worries that a larger flood event would change the course of the river entirely, diverting it north into the channel of the much-smaller Sumas River.. 17 May 2018. 29 November 2021.
  5. Web site: Group tasked with preventing major Fraser Valley flood hasn’t met in seven years. Today In BC. In 1990, the Nooksack River in northern Washington overflowed its banks, with its waters flooding over the border and into Sumas Prairie. The flood cut off Highway 1, and also inundated the towns of Everson and Sumas.. 3 September 2018. 29 November 2021.
  6. Web site: Province was warned breached B.C. dike 'substandard' years before it failed . CBC. As recently as 1990, the Nooksack River overflowed, flooding parts of Washington state and north into Abbotsford's Sumas River basin.. 26 November 2021. 29 November 2021.
  7. Web site: Nooksack River flood risk study gets go-ahead after years of task force inaction. Today In BC. When the Nooksack topped its banks in 1990, its waters inundated parts of Sumas Prairie and closed Highway 1 to traffic for 26 hours.. 2 October 2019. 29 November 2021.
  8. Web site: 2021-11-16. Immediate evacuation order for Sumas Prairie due to landslide in Abbotsford. 2021-11-16. Abbotsford News. en-US.
  9. News: Hauser. Christine. Chung. Christine. 2021-11-16. Evacuations Continue After Mudslides in British Columbia. en-US. The New York Times. 2021-11-16. 0362-4331.
  10. Web site: Canadian Army to build levee in Abbotsford in bid to save Sumas Prairie. 2021-11-19. vancouversun. en-CA.