The North Shore Mountains rise from Burrard Inlet and are characterized by numerous steep channels. This terrain, combined with the wet coastal climate, makes the North Shore vulnerable to landslides and debris flows.
A landslide is the downward and outward movement of debris, such as rocks, boulders, soil, sediment or logs. Materials may move by falling, toppling, sliding, spreading or flowing. The rate of movement can range from virtually imperceptible to greater than 100 km/hour, and the volume of debris can range from a few cubic metres to millions of cubic metres.
Landslides can be caused by many factors, including heavy rain, rapid snowmelt, erosion, human modifications of land, earthquakes, and volcanic eruption.
How to prepare
Start with the fundamentals of landslide preparedness:
- Make an emergency plan. Consider the needs of all household members, including pets
- Make an emergency kit
- Sign up for Alertable, the public emergency notification system used on the North Shore
- Limit the time that you spend in potential landslide areas, specifically during periods of fast snow melt or heavy rainfall
- Never stop your vehicle in a section of highway that has been marked as a landslide zone
- Be aware of when landslides are more likely to happen, such as during periods of heavy rainfall or atmospheric river events, fast snowmelt, or changes in temperature from below freezing to above freezing
Recognize landslide indicators
If you observe signs of an active landslide or debris flow, move to a safe location and call 9-1-1. To report potential landslide indicators, contact your municipality’s public works department or call the Province’s 24-hour toll-free number at 1-800-663-3456.
- Rapid changes or pulses in stream flow (e.g., changes in volume) or pulses of sediment (e.g., changes from clear to murky water)
- Abnormally dirty water
- Accumulation of large logs or debris
- Rapid accumulation of sediment or bed-load along a flat section of a creek channel
- Tension cracks near the top of a slope
- Falling rocks or boulders or flowing or sliding soil. This may precede a much larger landslide
Prepare your home
If your home or property is in a landslide risk area, there are steps you can take to help reduce risk and identify potential concerns early.
- Avoid actions that would make slopes unstable
- Do not undercut a steep bank
- Do not build near the top or base of steep slopes
- Do not place fill on steep slopes
- Do not drain pools or otherwise increase water flow down steep slopes
- Regularly inspect your residence, especially after heavy rainfall or atmospheric river events, rapid snowmelt, long dry spells, and earthquakes
- Know who to contact if you have concerns about slope stability, such as your municipality or a qualified geotechnical professional
What to do during a landslide
Keep clear of falling debris
- If you are indoors during a landslide, evacuate immediately. Inform neighbours if you can safely do so and call 9-1-1
- If you are indoors and cannot safely evacuate, find cover in the section of the building that is furthest away from the approaching landslide, take shelter under a strong table or bench, and hold on until all movement has stopped
- If you are outdoors during a landslide, move quickly away from its likely path. Keep clear of embankments, trees, power lines, and poles
- If you are driving, watch for collapsed pavement, mud, fallen rocks, and other signs of a debris flow
- If you are caught in a landslide with no option to evacuate to safety, curl in a tight ball and protect your head and neck
Leave the area immediately if you observe the following:
- A faint rumbling sound that increases in volume
- Unusual sounds, such as trees cracking or boulders knocking together
What to do after a landslide
Take the following steps after a landslide to ensure your safety:
- When you are safe, report the situation by calling 9-1-1
- Listen to local radio or television stations for the latest emergency information
- Stay away from the slide area as there could be subsequent slides
- Watch for flooding, which may occur after a landslide or debris flow
- Stay away from damaged utilities such as electrical lines and gas lines
- Take photos of landslide damage in case you need them for insurance purposes