A report to the Christchurch City Council recommended the use of emergency mobile alerts sent directly to compatible cell phones as the new primary method to raise the alarm of a tsunami. The phone alerts are still received even if the network is down.
New sirens could be installed in vulnerable locations where there is limited cell phone coverage. The number of sirens and locations has yet to be confirmed, but is expected to be in the range of four to six.
But people in Sumner are at odds with the city council over the decision.
Sumner Community Residents’ Association chair Andrea Davis said the removal of the sirens would impact on elderly residents.
“These older people, they don’t pay attention to their phones. They don’t have their phones in their pockets like younger people,” she said.
“I just think it’s a little bit silly to take sirens away that are already there. I mean, wouldn’t you rather have more warning than less?” Davis said.
She also emphasised the sirens’ importance for beach-goers.
“ I would hope that they understand that there are thousands of people here on a weekend in the summer and we actually need sirens.”
However, New Brighton Residents Association spokesperson Brian Donovan has a different view.
“I think it’s probably the right decision. There’s more to warning people in this environment than just relying on sirens.”
The tsunami alert sirens failed to sound during a planned test in April, because the Auckland-based contractor responsible for setting them off was dealing with a car crash outside their property at the time. The network trigger could not be operated locally.
The city council conceded having an emergency system so dependent on one person was unacceptable.
Donovan said a big issue facing people in New Brighton was getting away from the area in the event of a tsunami - the Pages Rd bridge being too much of a bottleneck.
Plans are under way to replace the earthquake-damaged Pages Rd bridge, which was left off the Government’s fast-track project list last year.
The city council safety review found the ageing tsunami warning system was not fit-for-purpose and should no longer be considered suitable as a primary alert method. It noted the sirens provide limited information on the hazard, were reliant on power and could be inaudible in windy conditions.
The sirens were established on ageing technology and infrastructure, and needed to be upgraded or replaced soon as they near the end of their 15-year life cycle. However, the city council ruled out both options, saying it would be expensive and not be fit-for-purpose.
Decommissioning and removing the existing 45 tsunami warning sirens and installing four to six new ones is expected to cost $2.6m.
Operation and maintenance of the new sirens will cost $70,000 a year.
A city council spokesperson said the planned test of the tsunami alert sirens on Sunday, July 13, will still go ahead.
