Map of Papamoa and Mount Maunganui tsunami evacuation zones.

Map of Papamoa and Mount Maunganui tsunami evacuation zones.


Tsunami warning sirens have shot back into contention as a major community issue for Tauranga - only six weeks after the city council decided to abandon them.

The devastation inflicted on Japan has ramped up pressure from Mount Maunganui and Papamoa ratepayer organisations, and even from within the ranks of the council where Bill Grainger had been the lone voice for sirens.

A quick poll of the Mayor and some councillors showed a strong preference to relook at sirens as a way to warn the city's vulnerable coastal suburbs.

Mayor Stuart Crosby today said the council needed to find the most effective mechanisms and if that required a rethink of sirens, then that's what would happen.

Leading the charge is the Papamoa Progressive Association which decided this week that sirens should be an important element in a mix of measures to alert people.

Newly elected chairman Steve Morris said more than six years had passed since the Indonesian Boxing Day tsunami of 2004, but still there was no alert system in place for Tauranga's vulnerable coastal suburbs.

"The community must have confidence in the tsunami warning system. Here in Papamoa, people want to hear sirens."

Previous tests using fire station sirens showed they were confusing and not enough people heard them. He favoured new super-loud sirens with their own special tone.

Mr Morris said the most likely source of a tsunami generated near the Bay of Plenty would be from an earthquake along the Kermadec Trench, halfway between East Cape and Tonga. It would give very little warning time.

A tsunami less than half the height of the one which struck Japan has been dubbed a "worst case" tsunami by the Bay's Civil Defence planners.

It would inundate Tauranga's lower-lying areas closest to the dunes or harbour margins, while an "extreme" 6.75m surge would flood the entire coastal strip and the rest of the city's harbour margins - hitting 19,000 homes and forcing 35,000 people to flee for their lives.

The Bay of Plenty Times last August published a map showing this projected devastation and has today reprinted it after the Japan disaster and controversy surrounding sirens in the Bay.

The association intends heeding the advice of Cr David Stewart, who attended Monday's meeting and make a submission to the council's 2011-12 annual plan. Submissions open on March 21.

Cr Stewart said safety was of paramount importance and whatever system gave the widest coverage and alerted the greatest number of people was what the council should aim for.

Sirens were easy to grasp, which was why people focused on them, but he said the council needed to test the advice it received from Civil Defence experts on the best systems to alert people. "People panic when they hear a siren. They jump in their cars and head for the hills."

Mount Maunganui Progressive Association chairman David Burnett said the Japanese experience had shown that Tauranga needed to take tsunamis "a hell of a lot more seriously". He liked the idea of sirens running in tandem with other measures supported by the council six weeks ago, including Readynet - a system which alerts specific areas and groups of people by email and text messages.

Cr Murray Guy originally voted for the new system earlier this year which dropped sirens in favour of a package which included non-rate funded remote controlled household alarms.

He said January's decision had been based on affordability but he now preferred coupling sirens with other technologies.

Judging by his informal talks with other councillors, Cr Guy expected the emphasis to swing back to sirens.

Cr Tony Christiansen said he was starting to change his views on sirens and that going back to the old air raid sirens might be best.

Cr Catherine Stewart said that she said at January's meeting that sirens had a place because they could be widely heard. "I would be happy to revisit it."

Cr Rick Curach was impressed at how loudly the sirens could be heard on the footage from Japan and some investigation needed to happen. "A lot of people who heard the sirens (in Japan) were asking, where are ours?" Cr Curach said.

Cr Wayne Moultrie said sirens were not the sole answer and that the council needed to take expert advice.

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