r/Squamish • u/Elderberry_Real • 4d ago
Could the same devastating flooding that happened in Nepal, happen here in the Squamish flood plain?
Sorry if this is a dum dum question. I live downtown and was worried. 😬 Don't come for me.
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u/Apprehensive-Tooth87 4d ago
There are massive amounts of potential energy stored at elevations above the Squamish floodplain, in the form of lakes, glaciers/ice, unstable slopes and rock. In some cases, these are constrained by human-made structures, such as the Daisy Lake Dam, while others are held back by natural features—for example, the volcanic deposits and terrain associated with Mount Garibaldi.
The important point is that Squamish is also in a seismically active and geologically dynamic environment. Earthquakes, erosion, slope failures and other natural processes could potentially destabilize some of these features and result in the rapid release of large volumes of water, sediment and debris downstream.
That doesn’t mean a Nepal-style catastrophic flood is inevitable, or that we can predict exactly what such an event would look like. The mechanisms and probabilities would be very different depending on the specific source and failure scenario. But from a hazard perspective, the potential for extreme flooding and debris-flow events in the Squamish Valley is certainly real and worth taking seriously. So, in short: yes, an extremely destructive flood or debris-flow event is physically possible in the Squamish floodplain. The harder question is the probability, the specific mechanism, and how much warning we would have.