Time to learn from history and properly tackle disaster readiness

Tuesday, 22 April 2025

The National Emergency Management Agency (NEMA) national control centre in the Beehive bunker, which was activated in the aftermath of the Auckland Anniversary Weekend floods in 2023.

Reid Basher is a retired senior adviser in the UN International Strategy for Disaster Reduction.

OPINION: In 1931, severe flooding of China’s Yangtze River reportedly left a mind-boggling 2.5 to 3.7 million people dead. A further million people died that year from the Huang He (Yellow) River floods.

Nowadays, China’s flood deaths are a tiny fraction of these figures, thanks to modern early-warning and flood-management systems.

The stakes are also high for us in New Zealand, as recent big disasters have cost the country more than $100 billion altogether. Some risks can be avoided, but some cannot. That’s when warning systems come into play.

Early warnings allow public authorities, businesses and individuals to take action, to evacuate people, avoid fatalities and injuries and reduce damage. This means lower impacts for everyone and lower costs for the economy.

Studies worldwide have shown the economic benefits of warning systems far exceed their operational costs.

Cyclone Giselle - aka the Wahine storm - famously sunk the inter-island ferry in 1968, and caused significant damage along the North Island’s east coast, writes Reid Basher.

But Cyclone Gabrielle, which devastated Tairāwhiti and Hawke’s Bay in 2023, showed what can go wrong.

The cyclone itself was not a surprise. MetService had tracked it through the tropics for days before it reached New Zealand and had issued heavy rainfall warnings. But no flood warnings or evacuation orders were issued by the responsible authorities.

So when the Esk River broke its banks, in the early hours of February 14, 2023, hundreds of shocked people were forced to escape, some by swimming through surging water that reached up to roof level. Not all would make it; altogether 11 people died in the disaster.

Although MetService issues rainfall warnings, the responsibility for flood management and flood warning lies with the regional councils, and the responsibility for leading emergency management and evacuations lies with the National Emergency Management Agency.

The Esk Valley disaster was a tough lesson for these organisations. As a result, and with extra central government support, Hawkes Bay Regional Council is undertaking significant new investment to improve flood forecasting, flood management and flood works over the coming decade.*

Whakaari White Island, where 22 people died in 2019 after a volcanic eruption which had not been picked up by early-warning systems.

Climate change will have added to the rainfall, yet Gabrielle was almost a carbon copy of a storm in April 1938, 85 years earlier, which reportedly destroyed or damaged dozens of bridges and left a layer of silt 1m to 3m deep along the Esk Valley.

Severe damage also occurred in the region during Cyclone Giselle in April 1968 (this cyclone contributing to the sinking of the ferry Wahine), and again during Cyclone Bola in March 1988. How quickly we forget.

We know that effective warning systems combine four elements - a 24/7 hazard warning service; knowledge of what’s at risk; multiple ways to reach all those potentially affected; and the capabilities of authorities and the public to respond after receiving a warning.

A blaring siren isn’t enough. Everyone needs to know what the alert means, what’s at risk and what to do in response.

It’s usually one of the last three elements that causes trouble – the specific risks not being properly recognised, inadequate communications to those likely to be affected and ineffective responses by organisations and individuals. This was the case for not only Cyclone Gabrielle but also the Whakaari/White Island eruption in December 2019, when 22 lives were lost.

Bear in mind that warnings can never be perfect. Nature is too complex for that. No-one likes a false alarm, but it’s better to have an overshoot and be overprepared, than to have an undershoot and suffer.

An aerial photo of Esk Valley in Hawke’s Bay after Cyclone Gabrielle in 2023, where residents were caught unawares by the devastating flood which swept through the community.

In fact, overshoots are valuable as dry runs and can be counted a success if authorities and individuals responded and did the right things.

MetService is responsible for warnings of weather hazards, including for coastal storm surge. It also advises on slower-moving weather events like drought and El Niño and on fast-moving wild fires and airborne animal disease outbreaks such as foot and mouth disease. Niwa provides similar, competing information.

Warnings for landslides, earthquakes, tsunamis and volcanic eruption are the responsibility of the National Geohazards Monitoring Centre, operated by GNS Science.

To avoid the current duplication and confusion of weather warnings, the Government last year decided that MetService should be acquired by Niwa. This year it further decided that GNS Science and Niwa (with its MetService subsidiary) should be merged as a Public Research Organisation (PRO) for Earth Sciences, one of four new PROs to be created with the aim of reorienting New Zealand’s science efforts toward a greater focus on economic outcomes.

If the new PRO for earth sciences is going to be judged on its contributions to economic outcomes, there can be fewer more juicy targets than the nation’s poorly managed disaster risks, and staunching the billions of dollars that bleed out of the economy in disaster events.

Key tasks will be to upgrade risk assessments and disaster databases, integrate and beef up our national warning systems, strengthen the flood management capabilities of the 11 regional councils, and develop adaptations to looming climate change.

When hazards threaten, we all want authoritative warning systems, not competing stories from different agencies, and certainly not the misfire that Esk Valley residents faced.

New Zealand still has some work to do to achieve this goal. China’s experience shows it’s well worth the effort.

* An amendment was made to this article after the Hawke’s Bay Regional Council disputed Reid Basher’s statement that it had been found to have under-invested in flood management projects.