Many Coquitlam communities are shaped by desirable topography, including natural slopes and ravines that enhance your property’s locale. However, steep terrain can be susceptible to landslides if the slope becomes weak and unstable. While the risk of slope failure and landslides is relatively low, it’s advisable to watch for signs that may compromise a slope’s strength and structure.
Signs of Slope Failure
- Cracks along your yard near the slope
- Extensive saturation, i.e. after continuous periods of heavy rains
- Increase in water levels at the bottom of the ravine (when debris fills the channel bed)
- Leaning trees, retaining walls or fences
- Soil separating (moving) from foundations or structures
How to Protect Your Slope
- Avoid placement of sheds, pools, decks or patio at the top of the slope or adding excessive weight
- Avoid placing fill (yard waste included) at the top of the slope or near drainage channels, including building retaining walls to raise your property
- Comply with City guidelines and bylaws for your own protection
- Divert water away from the slope, including roof drainage
- Exposed soils increase slope instability; plant native trees suited for Coquitlam’s weather/climate
- If water is draining to the ravine or slope, pipe it to the bottom of the slope to prevent saturating the slope
- Maintain the slope’s vegetation to strengthen its stability
As a homeowner, you are responsible for managing and maintaining your lot, including steep slopes. If you see signs of instability on your slope, please contact the City’s Engineering and Public Works Department at 604-927-3500.
Steep Slopes and Zoning
The zoning bylaw related to building on slopes was updated in 2022 (City of Coquitlam Zoning Bylaw No. 3000 Part 5, Section 519.3.
If an applicant wants to build within a 'slope zone,' a slope hazard assessment report will need to be prepared by a qualified professional.
Please see our bulletin, Building On or Adjacent to Slopes, for more information.
You can also refer to our Slope Hazard Assessment Report Criteria and Checklists for detailed information to assist you.
Please refer to the 'Steep Slope Areas' layer of our QtheMap for additional assistance.
Annual Ravine Inspections
The City conducts ravine inspections annually to proactively manage the risk of landslides. Due to steep slopes in the Chines Escarpment, Associated Engineering conducted a slope stability assessment in 2013, a qualitative analysis based on interpretation of the topographic data and visual site observation. Golder Associates later conducted a detailed geotechnical investigation for properties along Corona Crescent.