Landslides (slope instability) – property hazard information

If active landsliding appears to be happening on or near your property, inform your insurance company, mortgage lender or landlord. Get specialist advice from a suitably qualified expert such as a structural surveyor, geotechnical engineer or chartered engineering geologist.

If active landsliding is not happening but the area has a potential for landslide activity, take specialist advice before starting major building or drainage work or modifying the ground around your property:

  • ensure water supply pipes and drains are in good repair and are not leaking
  • ensure ditches and drains are directed away from potentially unstable ground and are maintained
  • maintain gutters and down pipes and direct them to piped drainage systems
  • manage wooded slope to enhance stability
  • Do not remove material from the bottom of slopes
  • Do not place material on, or at the top of, slopes
  • Do not dispose of rainwater or surface water to soakaways
  • Do not allow surface drainage to discharge water on to slopes or the ground behind slopes
  • Do not remove vegetation whose roots may be strengthening loose or weak material or which may strengthen the slope by removing soil moisture

If you have received a GeoReport the following key provides further information on the BGS landslides (slope instability) hazard rating:

Potential for landslides and advice for preventative or remedial action

  Hazard rating Advice for public Advice for specialist
A No indicators for slope instability identified. No actions required to avoid problems due to landslides. No special ground investigation required or increased construction costs or increased financial risk due to potential problems with landslides.
B Slope instability problems are unlikely to be present. No actions required to avoid problems due to landslides. No special ground investigation required or increased construction costs or increased financial risk due to potential problems with landslides.
C Possibility of slope instability problems after major changes in ground conditions. Ask about implication for stability if large changes to drainage or excavations take place near to buildings. New build – Consider possibility of trench side or slope movement during excavations, or consequence of changes to drainage. Possible increase in construction cost to remove possibility of potential slope stability problems.

Existing property – No significant increase in insurance risk due to natural slope instability problems.

D Significant potential for slope instability with relatively small changes in ground conditions. Avoid large amounts of water entering the ground through pipe leakage or soakaways. Do not undercut or place large amounts of material on slopes without technical advice. New build – Assess slope stability of site and consequences of excavation, loading and water content changes during and after construction.

Existing property – Probable increase in insurance risk due to natural slope instability after changes to ground conditions such as a very long, excessively wet winter.

E Very significant potential for slope instability. Active or inactive landslides may be present. Seek expert advice about stability of the ground and its management to maintain and increase its stability. New build – Slope stability assessment necessary, special design may be necessary, construction may not be possible.

Existing property – Significant increase in insurance risk in some cases. Site-specific consideration is necessary to separate cases where landslides are stabilised or ancient and stable from those that may be active or may fail.



You may also be interested in...

  • I have received a hazard rating from the BGS and would like more information
  • Buy a GeoReport giving details of six ground stability issues for a particular area or property
  • Apply for a digital data licence for GeoSure data sets from our IPR Section
  • Contact Enquiries for more information on the GeoSure data sets and reports
Hutton field: well correlation diagram.