Mt. Nusatsum

Mt. Nusatsum

Thursday, November 5, 2009

Flood History

Last comment on floods this year (hopefully).

Here is an history of some notable flood events in the last 50 years in the Bella Coola Valley

  • Nov 3-4, 1950 180.3 mm - Flood isolated Hagensborg, plans for new bridge to Salloompt had to be altered.
  • Oct 16-21, 1965 183.1mm - Seven bridges and a section of road washed out.
  • Jan 23, 1965 - Rain on recent fresh snow and freezing level up to 10,000 feet. Two bridges washed out, Hagensborg flooded, telephone exchange knocked out. A Sikorsky helicopter was on standby to evacuate.
  • Jan 21-23 1968 157.5 mm - A total of 186cm of snow had fallen to date, likely snow on the ground of 50-80 cm in the valley, freezing level rose to 3400 metres.  Bella Coola River rose 11 feet. Large flood.
  • Sep 25-26, 1973 103.1 mm.  - Major change in the Big Bend of the river. Upstream of Tatsquan was cut off.  The old channel which had persisted for over a century was filled with sediment.
  • Oct 29 – Nov 1 1978 101.2 mm. - Rip rap at airport eroded, Wilderness Air float plane terminal in the river was damaged and dock area infilled with gravel, Burnt Bridge Creek overflowed along the highway, damage in Salloompt, damage in Thorsen Creek.
  • Dec 7-15, 1980 340.4 mm (7 days) - Airport flooded, highway closed, Nusatsum River flooded the dyke.
  • Sep 26-29, 1988 - 149.8 mm  Salloompt flooded
  • Nov 7,8, 2004 159.5 mm – Many forestry roads washed out.
Source: Rainstorm and Flood Damage Northwest British Columbia 1891-1991 and personal records.

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