Who is responsible?
In general the owner of the land is responsible for repairing a slip on their land. If your neighbours land has moved and caused damage, they don’t automatically have an obligation to repair it, even if it affects you, unless they caused the slip by their own negligence.
All landowners have a general duty of care to act reasonably to prevent or mitigate damage to a neighbour’s property due to a hazard on their land once they are aware of it – so if you have concerns about a neighbouring property, you get professional advice and should inform them in writing.
Inform your insurer
If your house or land is damaged, you may be able to make a claim with your insurance company or EQC. You can find out more about what’s covered here. EQC have a set of rules and criteria, so you will need to lodge a claim with them to find out if you’re covered.
Get professional advice
Contact a local engineering consultancy to provide advice. If you have insurance, and the claim is valid, they should arrange this for you. Ask for a Professional Engineering Geologist (with PEngGeol registration) or Geotechnical Engineer (with CPEng registration).
If you’re looking for a professional to help solve a geotechnical problem it is important that you use appropriately qualified geotechnical professionals. You’ll need either a Chartered Professional Engineer who specialises in geotechnical engineering, or a Professional Engineering Geologist. Look for the qualifications CPEng (Geotechnical) or PEngGeol. These are the quality marks administered by Engineering New Zealand, and the holders of these certifications are held to a high standard of professionalism and follow the Engineers New Zealand Code of Ethical Conduct, available here.
Do I need a Geotechnical Engineer (CPEng Geotechnical) or Engineering Geologist (PEngGeol)?
Engineering Geology is the profession responsible for defining the geotechnical problem, and identifying and characterising the hazards and material properties. Geotechnical Engineers then take this information to design the appropriate solution. These two functions work together to ensure a safe design. If you’re not sure which you need, ask a professional. You can check if the person you’re getting advice from is suitably qualified by checking the list here – you can search for them by name.
- Geotechnical engineers should have “Geotechnical engineering” in their Practice Field and should have “CPEng” as their post-nominal.
- Engineering geologists should have “PEngGeol” as their Membership.
Not everyone that works on your project needs to be registered, but you should insist that the person responsible for signing any formal documentation is on one of these two registers to protect your interests.
Detailed advice from MBIE
You can find out more here: https://www.building.govt.nz/assets/Uploads/managing-buildings/slope-stability-quick-guide.pdf
Planting to stabilise slopes
As long as a landslide doesn’t imminently threaten a house or other critical assets, one of the easiest and sometimes most effective ways to prevent a landslide getting worse is to re-plant it. The guide below gives a useful starting point. The recommendations are focused on Auckland, so speak to your local garden centre for advice about which species might suit your climate in other regions.