Protecting our future by investing early in resilience

Earlier this year, severe storms and flooding again highlighted how vulnerable parts of Aotearoa can be to extreme weather events. Landslips, rockfall and debris flows triggered road closures across the transport network, leaving some communities cut off from essential services.

These events feel all too familiar. Since Cyclone Gabrielle in 2023, we have continued to experience more intense rainfall. That change brings greater damage, longer recovery periods and significantly higher rebuild costs. The impacts extend well beyond the immediate aftermath, affecting communities, supply chains and public finances.

The Parliamentary Commissioner for the Environment noted that spending on the environment has remained consistent in recent years, but the composition has changed, with major increases in recovery efforts (NZD 666 million additional since 2023). That shift prompts an important question: what would it look like to invest earlier, so we rely less on repeated repair and recovery?

Since 2023, we have been working alongside the NZ Transport Agency – Waka Kotahi (NZTA) as part of the South Island Resilience Panel. The panel aims to strengthen the long-term resilience of key transport routes by improving our understanding of natural hazard risk and using that insight to support proactive and preventative investment.

As part of this panel, two Single Stage Business Cases (SSBCs) and an Investment Case have been delivered and are now in various stages of design and implementation. The goal is to build a deeper understanding of risk to our communities so decision-makers can prioritise targeted interventions, rather than relying on repeated emergency works after each event.

High-risk sites across the state highway network face increasing exposure to hazards associated with heavy rain and strong wind. For many locations, intensified rainfall acts as the primary trigger for road closures. Even small increases in rainfall intensity can set off rockfall, slips, flooding and other forms of disruption.

These routes serve as essential lifelines for remote communities and the tourism sector, yet storm events can disrupt them frequently. While forecasting future weather patterns remains complex, we do know that as global temperatures rise, extreme rainfall becomes more intense. NIWA estimates that for every 1°C increase in temperature, short-duration extreme rainfall events – such as a 1-in-100-year, one-hour storm – intensify by around 13.6 per cent.

That evidence reinforces the value of early planning. When we understand how hazards are likely to behave at specific sites, we can define practical options and invest in the right solutions before failures occur.

When a closure happens in a remote location, it can affect more than travel time. These routes are often the only way in, out, or through a region. A single closure can limit access to supplies and services, disrupt freight movement and affect tourism flows that local businesses rely on.

At Epitaph, for example, the alternative route from Fox Glacier to Hāwea adds 516 kilometres – more than six hours for tourists, and even longer for freight. The impact on the regional economy, plus the additional transport costs, can run into tens of millions each month. While it can be difficult to quantify the full effects, it’s clear they are significant and prolonged closures can even shift local economic patterns over time.

We commenced the SH6 Haast to Hāwea SSBC in mid-2024, working alongside New Zealand Transport Agency – Waka Kotahi, with a focus on 20 high-risk sites, including the Epitaph site, located 22 kilometres north of Hāwea. This stretch of highway has a long history of repeated rockfalls, landslides and major underslips that have challenged its resilience and reliability since it first opened in the 1960s.

By October 2024, we had begun three-dimensional ground modelling and targeted site investigations to better understand the risk of major landslips. We also worked to quantify the impacts of a prolonged road closure to local businesses, the community, tourism sector and freight industry.

Just a month later, in November 2024, a heavy rainfall event triggered significant rockfall and road slumping, leading to a 13-day road closure of SH6 at Epitaph. The timing reinforced the urgency of understanding the site conditions and moving quickly from analysis into practical action.

By early 2025, the modelling was complete, providing a clearer picture of ground conditions, including likely failure mechanisms and longer-term impacts. In mid-2025, NZTA carried out emergency stabilisation works at the site, constructing a micropile wall to support the road and road edge. This helped reduce the immediate risk of underslips and further closures while investigations and planning continued to support a longer-term solution.

In November 2025, the NZTA Board approved funding for the design and consenting of long-term resilience works at Epitaph. This approach aligns with the Government Policy Statement on Land Transport 2024–27, which calls for smarter investment in resilience. By anticipating risks and acting earlier, the panel is helping to limit disruption, reduce emergency response costs and support faster recovery for affected communities.

Resilience sits at the heart of keeping New Zealand moving. While we cannot predict exactly when or where a major event might occur, we strengthen the transport network by improving our understanding of the risks, identify their causes, and investing in targeted interventions.

Through design, informed by technical expertise and local insight, this panel is helping create transport systems ready to respond to future challenges. Resilience isn’t just about the infrastructure itself – it’s about protecting the communities, businesses and people who rely on it every day.