Council to consider report on reducing tsunami siren network

Christchurch City Council will consider a report, at its meeting next week, recommending significantly reducing the number of tsunami sirens along our coastline.

Currently 45 sirens are located along the coastline between Brooklands and Taylors Mistake. However, if the Council approves the recommendation, sirens will only be considered in evacuation zone areas where there is limited cell phone coverage. This is expected to be in the range of four to six sirens.

The recommendation comes after a review into the Council’s tsunami alerting system which concluded that sirens cause confusion on what to do in an emergency and having them as a primary alerting method is inconsistent with national and international best practices. The review recommended the Council uses Emergency Mobile Alerts (EMA’s) as the primary alerting method. A small number of strategically positioned sirens, along with other media methods, would be used as a secondary alerting system. 

Civil Defence and Emergency Management Manager Brenden Winder says using the text alert system as the single primary alerting method aimed to minimise confusion on what to do in an emergency.

“In the rare event of a tsunami, our top priority is preventing loss of life. This relies on having a straightforward and effective alerting system, giving residents a clear message to evacuate.

“Sirens are no longer considered to be a suitable primary tsunami alerting method as they cause confusion and delay communities responding effectively. Mobile alerts are used nationally as the main alerting method in an emergency. This sends a clear message straight to the user’s phone on what action to take. We want people to act quickly and decisively in an emergency, and a text alert provides that direction. As a result, we’re recommending that we continue to use Emergency Mobile Alerts as the primary alerting method.”

Mr Winder says, if the recommendation was approved, a small number of sirens would remain in areas with limited cell phone coverage.

“The locations and number of sirens will be confirmed by detailed modelling and a risk analysis.”

Read the report to be considered by the Council here.