Avalanche Hazard

Avalanche shoots in British Columbia

A geologic hazard that has been added to several county geologic hazard areas designations is avalanche hazards. With potential future development of mountain valley properties associated with winter recreation, it is not a bad idea to consider this risk. Ideally the hazard will be recognized prior to zoning changes that would allow homes or development in these areas.

The potential areas impacted in Washington State are pretty minimal. I took a look at this potential hazard for one county and found no areas of potential development areas that could be impacted presuming no radical shift in snow fall amounts on the lower elevation areas of the county.

With a few limited exceptions avalanche hazards in Washington State are outside of development areas. I encountered one site that had deposits of large wood, boulders and soil that were a bit perplexing because I was not thinking about avalanche hazard. A review of historic aerials helped. Although no avalanches were reported, the on the ground indicators of a were consistent with a past avalanche out of a high meadow 3,000 above that reached the valley floor. Avalanche hazard assessment requires some consideration of extreme weather events much like landslide hazards, alluvial fan hazards and flood hazards.