Geotechnical engineers and specialists have completed 1000 assessments across Auckland, with another 180 assessments underway, to determine the ‘intolerable risk to life’ from future landslides, in the wake of devastating storms in early 2023.
“At its heart, this is about keeping you and your whānau safe when in extreme natural events. Some homes and neighbourhoods may be vulnerable to a future landslide risk that is unacceptably high, and we are doing what we can to keep people out of harm’s way. This includes providing evidence about ground stability so homeowners can make informed decisions about their safety,” says Mace Ward, Deputy Group Recovery Manager.
The Tāmaki Makaurau Recovery Office (Recovery Office) has contracted ten geotechnical suppliers, using over 100 specialist engineers and consultants to collect data for people concerned about unstable slopes near their property. The objective is to help people understand if future severe storms will result in a landslide that poses a risk to life, and whether that risk can be managed so it is safe to live in their property. Actions that can be taken to manage risk may include modifications to a property or the surrounding area to create resilience.
Geotechnical and flooding assessments are a free service provided by the Recovery Office to help residents understand natural hazard risks to their property. If you would like to participate, you can complete this online form.
“There were several thousand landslides across Tāmaki Makaurau earlier this year, impacting land and property on a scale not previously experienced. The assessments provide us with the information we need to apply a risk category to your home, also known as property categorisation,” says Mr Ward.
Geotechnical experts are busy behind the scenes, collecting information for household assessments via a mix of desktop and on-site methods – a significant number of properties will need both types of assessments. Desktop assessments are particularly labour intensive and can take up to three weeks per property and involve a number of different assessments. Several specialists are involved, collating data in their area of expertise to contribute to the overall picture for a particular property or area.
GHD is one of the geotechnical suppliers contracted by the Recovery Office – according to their Technical Director Matt Howard, there is a shortage of engineers to meet the demand for assessing storm damage in several regions across New Zealand. The supply problem is not just with the Recovery Office, it extends across other sectors such as insurance and EQC (Earthquake Commission) geotechnical assessments.
“We recognise that some homeowners are feeling anxious because they haven’t got their geotech report and initial risk category for their property. We understand that people want certainty so they can make decisions and move forward with their life. This is what we are focused on providing,” says Mr Ward.
Mr Ward says the Recovery Office is throwing everything into bridging the resourcing gap to unblock the pipeline of work and speed up assessments.
“We’ve granted approval for our suppliers to import engineers from overseas to expedite on-site assessments in Auckland and export some desktop work to Australian specialists. People who own storm damaged properties have been on a difficult journey this year and we’re doing everything we can to help them,” says Mr Ward.
Mr Ward clarifies that overseas labour transition takes time, with geotechnical specialists arriving in Auckland over the next few months.
Frequently Asked Questions
Do I need a geotechnical risk assessment?
In some cases, it will be obvious that a risk assessment is needed – for example if the weather events this year caused damage. Other properties may not have sustained any or much damage at all but are in areas that we suspect may be at risk in future. If you are unsure or concerned about your landslide risk, we recommend you complete this online form.
What information do you collect in the desktop geotechnical assessments?
The desktop assessments involve information collection from property files, photographs, published geological information and LiDAR data to calculate slope angles.
What information do you collect through onsite geotechnical assessments?
The onsite assessments collect information to allow an assessment of the geomorphology (land shape), which informs an assessment of the ground stability at each property. In high-risk locations such as Muriwai there are also below-ground investigations and monitoring to provide detailed information on the locations of geological boundaries that affect slope stability. Where appropriate for the landslide style, engineers have created three-dimensional debris flow modelling for typical scenarios to calculate risk for homeowners.
What is the timeline for a geotechnical assessment when I fill out the landslide and flood registration form?
Click here to view our geotechnical timeline.
Is the landslide risk assessment the same as what you would find in other countries?
Yes, the risk assessment follows the procedures outlined in the Australian Geomechanics Society 2007 guidelines, which represent internationally accepted best practice. More information on these procedures is available on the Landslide Risk Management website.
What is the difference between an EQC vs a Recovery Office geotechnical report?
While both assess landslides, an EQC report typically focuses on damage to the insured property. The Recovery Office geotechnical reports assess long term risk to life.
Does the risk equation in the geotechnical report take weather patterns into account?
Yes, we consider the weather patterns that are likely to occur over the next 100 years. This is based on current, previous and future weather predictions. We also consider the likelihood of drought, as that would affect land stability too.
I want a flooding assessment how do I make this happen and what can I expect?
You can read more information in this Our Auckland article: Risk assessments for flood affected homes.
Where can I get more information?
There is more information available with the Our Auckland landslide and liability story.
What support is the Recovery Office providing for storm affected property owners?
Visit the support page on OurAuckland to discover what is available to you. Email navigators@aucklandcouncil.govt.nz if you’re a storm affected property owner and want to discuss support options for mental health, finance, insurance or accommodation.
