A tsunami mass warning system that talks, telling anyone within earshot what danger is coming and what to do - in multiple languages.

That was the subject of a presentation yesterday to the Tauranga City Council committee charged with coming up with a system for warning Tauranga's 45,000 coastal residents of an imminent tsunami.

Mark Wolf, founder of Australian emergency alert technology company Emalte, spoke to the community and culture committee about the kinds of systems his company had worked on around the world, including in Malaysia and the United States.

He said the mass warning systems his company used - including omnidirectional pole-mounted speakers elevated to at least 15m that could be heard within a 1.8km radius - had many advantages over World War II-style air-raid sirens previously favoured by some councillors.


His systems could make different alert noises for different types of disasters and have up to 16 pre-programmed voice messages - including a test message. They could also be used for live public addresses.

"Instruction and direction saves lives. The purpose of the alert is clear," Mr Wolf said.

Councillor Steve Morris, who invited Mr Wolf to speak to the council, asked for a ballpark figure on what 11 warning towers might cost. Mr Wolf said it would be about $800,000.

He said false alarms could only happen if someone pushed the button. The system could also be tested silently, and checked from a phone.

Councillor Larry Baldock was interested to hear that because getting resource consent for sirens that might be installed close to homes was one of the obstacles the committee faced.

Councillor Leanne Brown asked whether there was nationally recognised sound in Australia for a tsunami.

Mr Wolf said it was not the sound that mattered, but the message that came after.

He encouraged the council to choose its system carefully and avoid cheap options.

Whatever system they chose had to withstand constant battering by coastal conditions, as well as actual natural disasters, he said.

Committee chairman Terry Molloy said the presentation was "incredibly useful" in helping the committee make its decision.

In August the committee ruled out air raid sirens because the noise they make will become illegal in three years under a Ministry of Civil Defence and Emergency Management policy.

The council asked staff to go away and gather more information about two warning system options: electronic speaker sirens mounted on power poles and small in-home sirens.

Staff will report back at an open workshop on October 17.