Living Near Steep Slopes

Risks of ravine or bluff slopes

Slope failures and landslides typically occur after an extended period of heavy rainfall. The excessive amount of water causes the soil structure of the slope to weaken.

View the Steep Slopes Brochure to learn about proper property management.

A number of things can affect the stability of the slope on your property. Your property use decisions at the top of the slope can influence the neighbours you beside you and below you.

Responsible stewardship

The owner of the lot is responsible for looking after their lot, regardless of whether the lot was developed before or in accordance with the City's current land development or building permit applications procedures.

To avoid future slope stability issues for properties located on or near slopes in Surrey, we look out for certain measures in open land development and building permit applications.

Measures to address slope stability concerns include:

• geotechnical evaluations,
• increased building setbacks,
• deep foundations,
• the control and conveyance of stormwater, and
• the planting and maintenance of vegetative ground cover on the slope itself.

Ravine stability assessments

Surrey also completes a Ravine Stability Assessment every two years. The City will be inspecting Surrey’s ravine slopes and channel banks beginning November in 2022 through to April 2023.

During an assessment, all ravines in the City are inspected and erosion zones are documented and classified. A Professional Engineer further examines any sites with significant erosion and recommends remedial actions to mitigate risks of slope failure.

Signs of a slope failure

• Springs, seeps or saturated ground in areas that have not typically been wet before
• New cracks or unusual bulges in the ground
• Soil moving away from foundations
• Ancillary structure, such as decks and patios, tilting and/or moving relative to the main house
• Tilting or cracking of concrete floors and foundations
• Leaning telephone poles, trees, retaining walls or fences
• Quick increase in water levels associated with increased turbidity or muddiness in water

Concerned about your slope or considering building a retaining wall? Contact a Professional Engineer or Professional Geoscientist.