Landslides

Risk: Moderate

Landslides include a range of downhill earth movements, including slope failures, and rock falls. Landslides can be extremely destructive and are caused by a number of pre-existing and contributing factors including heavy rainfall or rapid snowmelt, erosion, poor construction practices, freezing and thawing, earthquakes and volcanic eruptions (SLRD, 2015).

Due to the mountainous topography and high levels of annual rainfall, Squamish and the surrounding area are highly susceptible to landslide events. Landslide events are common along the steep valley walls and have resulted in significant alterations to river grades over the past several hundred years. Climate change is projected to increase landslides as an indirect impact of more and heavier rain.

There have been a number of significant landslides in the area around Squamish, including the 2008 Porteau Cove rockfall which closed Highway 99 for 5 days. More recently in 2015, a large rockfall occurred on the Chief. The slide happened just before 12 p.m. PT when what police describe as a 1,000 cubic metre granite slab fell away from the mountain in the North Walls area of the north peak, near a climbing route called Northern Lights.

Video Link