Opinion: Tsunami warning system needs a major overhaul - Celeste Donovan

Christchruch Coastal Ward city councillor Celeste Donovan responds to the failed tsunami siren test earlier this month.

The failed tsunami siren test in New Brighton was a wake-up call – one we can’t afford to ignore.

It didn’t fail because of bad weather or a one-off glitch – it failed because the system is manual, has no back-up, no local control, and no place in 2025.

Our coastal warning network relies on an Auckland-based company using outdated technology with no local activation ability. That’s simply not good enough for a community living right on the coast, where time matters in an emergency.

Our tsunami sirens are no longer fit for purpose. Installed over a decade ago, they’re vulnerable to power cuts and internet outages. The system runs through SCADA (supervisory control and data acquisition), set up in 2012 and expanded in 2015. At the time, manual activation was the only option, but that is outdated now.

The sirens can also be hard to hear, especially on windy days or out on the beach. A similar issue occurred during the 2016 Kaikōura earthquake when the sirens were slow to activate, leaving locals unsure whether to evacuate. The city council is still talking to the current supplier about reliability, but the system is old, fragile, and no longer serves our community’s needs. It’s not due for replacement until between 2027 and 2030, but that’s far too long to wait.

The planned April 6 tsunami test did not happen because the Auckland-based person responsible was dealing with a car crash outside their property at the time. PHOTO: CCC

A review of Christchurch’s tsunami warning and alert systems has been under way for more than a year and will be presented to the city council in mid-June. I’ll be pushing for upgrades to be fast-tracked through the council’s Annual Plan process and for community involvement to be at the forefront.

We need a modern, locally controlled system built for real-world conditions. The technology already exists. New systems can do more than just make noise – they can act as multi-functional sensors, improving coverage and accessibility. We must also explore tools that work better for our deaf and disabled communities, like visual signals, vibration-based alerts, and mobile apps offering real-time updates.

I’m also calling for increased funding for local emergency response planning.

Communities know their people, land, and risks – they’re often the first to respond. A recent Government inquiry into Cyclone Gabrielle made it clear: Agencies expect communities to “step up”, but many don’t realise they’re part of the emergency system. That leaves them feeling unprepared when disaster strikes.

To be clear: Tsunami sirens are just one tool. Emergency Mobile Alerts (EMA) are the primary national warning system, and they work. But people also need to recognise the natural warning signs. If the ground shakes or the sea suddenly recedes, don’t wait for a siren. Leave for higher ground.

If there was an imminent tsunami threat, Civil Defence and the police would alert residents using a combination of sirens, radio, TV, social media, and community networks. This failed test has reinforced what many of us already knew: the sirens are just one part of the puzzle. We need to go beyond them and ensure every household has a plan for when the sirens go off – or if they don’t.

We should explore new tools, like mobile apps that provide real-time updates, help check in with friends and whānau, and flag hazards like damaged roads or bridges. I’ll be making sure we explore all options to strengthen our emergency response.

One of my key aims is to keep working with our Civil Defence team, local communities and national partners to develop a modern, reliable system designed with real people in mind.

We owe that much to the communities who live by the sea.