A November to Remember Flooding in Southwestern British Columbia By Mike Pearson, B.C. Ministry of Transportation and Infrastructure
What Happened? It’s not uncommon for southwestern British Columbia
out rip rap armouring along riverbanks, and caused
(B.C.) to get significant rain and snow in November. In
mudslides and rockfall events in mountain passes.
2021, however, B.C. experienced an unprecedented event that saw a series of atmospheric rivers hit the
This resulted in the closure of all major highways
southwestern portion of the province over a 2-week
between the coast and the interior of the province (see
period from November 14 to December 1. Atmospheric
Figure 1). Highway 5 (also known as the Coquihalla
rivers are streams of water vapour in the sky carrying
Highway) was significantly damaged and closed due to
moisture from the tropics and releasing it as rain or
the loss of multiple structures between Hope and
snow at landfall.
Merritt. Highway 1 between Hope and Cache creek was closed in multiple locations due to the loss of structures
This series of events in late 2021 brought more than 540
along the highway including railway overpasses. The
mm of rain to the Fraser Valley and parts of Vancouver
most impacted corridor was Highway 8 between Merritt
Island, creating flooding conditions that overwhelmed
and Spences Bridge where along the 45-kilometre
culverts and dike systems, washed away bridge
highway there were 23 washouts and 7 kilometres of
abutments, damaged retaining wall structures, scoured
the road were simply gone. Highways 3, 7, and 99, also closed due to flooding and mudslides.
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TRANSPORTATION TALK | WINTER 2021-22
Credit: B.C. Ministry of Transportation and Infrastructure
Crews work to repair sites damaged by flooding near the Othello Interchange Peers Creek Bridge on Highway 5.