A new satellite map is giving insurers and public agencies a more detailed picture of landslips across East Cape after January’s deadly storm, identifying more than 11,000 slips and extensive silt coverage in the region.
The interactive map, developed by Wellington-based Dragonfly Data Science, compares satellite imagery taken before and after the storm to identify visible landslides and silt movement. The analysis shows more than 11,000 slips and about 900 hectares of silt-affected land, with several communities still dealing with disrupted access. The storm led to multiple fatalities, including six people who died in a slip at Mt Maunganui and two people killed in a separate slip in Pāpāmoa. The mapped pattern of failures shows numerous slips along coastal hills and steep terrain.
Dragonfly director of data science Dr Finlay Thompson said the damage is concentrated at the northern end of the peninsula, with “many slips along the side of coastal hills.” Transport disruption remains a key feature of the event: the coastal road between Te Araroa and Pōtaka is still closed while crews stabilise multiple slips at locations including Waikura and Punaruku. The Punaruku slip alone is estimated to involve around 250,000 cubic metres of material. “Although progress is being made to restore limited access for critical supplies and emergency services, ongoing land instability means there is currently no confirmed timeframe for reopening the route to the public,” Thompson said, as reported by Stuff.
Thompson said satellite imagery is being used for both immediate response and longer-term risk assessment. “It provides a bird’s-eye view of the area following an intense and highly localised storm event such as this, and offers an effective way of assessing how widespread and severe the damage is,” Thompson said. He said the current map is not, in itself, predictive, but can support more advanced modelling when combined with rainfall and terrain data from multiple events. “By linking storm impacts with rainfall and terrain data over multiple events, we could begin to build models that help predict where slips and flooding are most likely to occur in future,” he said.
Thompson linked the storm to a broader pattern of weather-related losses. “Cyclone Gabrielle was only the start of the extreme weather events that are becoming more frequent in Aotearoa, and we need better tools and planning in place ahead of time. People’s livelihoods are at stake. While response and recovery efforts are critical and effective, the reality is that communities are living through significant disruption and loss in the meantime, and that’s something we can’t afford to treat as normal,” Thompson said. For insurers and reinsurers, the new dataset is relevant to accumulation analysis, stress testing hillside and coastal portfolios, and discussions with councils and the Natural Hazards Commission (NHC) on mitigation priorities and land-use settings.
In Northland, a long-running dispute over damage to a home near Whangārei has underlined how engineering assessments and statutory definitions of landslip can affect access to cover. According to RNZ’s report, the homeowners noticed cracking and movement around their house in 2018 and lodged a claim with the Earthquake Commission (EQC, now the Natural Hazards Commission) in 2019. EQC declined the claim within a week, stating the damage was not caused by natural hazards. The couple initially accepted the decision and undertook drainage work, but further damage led them to seek independent advice.
In 2022, Whangārei geotechnical engineer David Buxton inspected the property and concluded it was landslide damage. EQC reopened the claim and sent a senior assessment specialist onsite, who recorded “widespread cracking of gib and ceiling from centre of house to the east end of house,” a driveway that had “pulled away from the curb,” buckling decking, and “ongoing slippage” likely to require land stabilisation and piling work.
Consultant firm WSP was then engaged. A senior engineer signed off a June 2022 draft report, prepared without a site visit, that attributed the damage to long-term subsidence associated with groundwater rather than landslip. A November 2025 ruling by the Chartered Professional Engineers Council later said: “There is evidence to suggest that this was not a sound conclusion to have been reached, or at least reached unequivocally, given the documentation available.” It also noted that the situation “had the potential to create an outcome in which insured homeowners were deprived of their entitlement to damage repair.”
After Buxton challenged the report, EQC instructed WSP to carry out a site visit and produce a further assessment. The September 2022 report, issued after the visit, revised the geological interpretation and concluded that “the damage to the property is landslip damage as defined by the EQC Act.” The ruling said that comparing the June and September documents was “demonstrative of the difference that undertaking a site visit made to both the quality of the assessment and the conclusion reached.”
Buxton lodged a professional complaint, arguing that declining cover without a site visit created undue risk for policyholders. The Chartered Professional Engineers Council found there was “sufficient substance” to suggest the supervising engineer’s actions “were below the standard expected” and could have had “significant consequences for the homeowner” without intervention, but ultimately declined to impose sanctions, citing factors including the engineer’s retirement and the threshold for disciplinary findings.
WSP said it is “committed to high professional standards and fair, accurate natural hazard assessments” and has strengthened internal guidance, peer review processes, and documentation of professional judgment. The NHC described its claims processes as “robust and fair,” pointing to a quality assurance programme that reviews technical assessments and noting that complex cases may involve an onsite engineer once new information is provided. For insurers, the case shows how causation disputes, the distinction between sudden landslip and gradual land movement, and the depth of engineering evidence can influence claim outcomes and timelines in land damage cases.
In Tauranga’s Welcome Bay, four homes that were red-stickered after a fatal landslip in last month’s storm have had their safety status downgraded, allowing controlled access while further technical work proceeds. Two people were killed when a large slip hit neighbouring homes on Welcome Bay Road. Western Bay of Plenty District Council said its consultant geotechnical engineers reassessed the properties after the event. As the land dried and “the ‘additional weight’ on the land reduced,” they concluded “the risk of imminent slip had reduced to a point where the properties could be accessed, under certain conditions.” Red stickers have been replaced with yellow: three homes now carry a Y2 notice, allowing short-term access, while one has a Y1 notice restricting access to particular parts of the building.
Council duty controller Peter Watson said further investigations will be required. “Additional geotechnical investigations for affected properties will need to be undertaken by the homeowners in conjunction with their insurance companies, to identify a way forward to remove the hazards,” Watson said, as reported by RNZ. The council is not considering an inquiry into the Welcome Bay slip, although an independent review is under way into the Mt Maunganui campground landslide, and the government may also consider an inquiry. Earlier technical work has referred to landslide susceptibility in the wider Tauranga area. A 1980 report titled “A preliminary assessment of geological factors influencing slope stability and landslipping in and around Tauranga city” stated: “Recent subdivisions in Welcome Bay should be examined by a geotechnical engineer as the area contains many inferred landslides, which may be reactivated by urban development.”
Watson said the Welcome Bay Road site where the recent fatal slip occurred was not subdivided until the 1990s, with the home built in 2000, so it was not one of the subdivisions referenced in the 1980 report. He said the council has not carried out a detailed, site-specific survey of landslide risks along that part of Welcome Bay Road, and instead requires that “the stability of subdivisions on sloping ground … is assessed and demonstrated by an accredited geotechnical engineer or geologist as part of the resource consent process.”
Subsequent studies in 1981, 2009, and a 2024 Bay of Plenty Regional Landslide Susceptibility Study have informed district plan hazard maps, but the regional work does not assess risk at the individual property level. Taken together, the East Cape mapping, the Northland dispute, and the Welcome Bay case indicate an increasing reliance on high-resolution hazard data, geotechnical input, and coordination among insurers, the NHC, and councils as rainfall-driven landslip risk continues to intersect with residential development across New Zealand.
