A civil defence volunteer is sounding the alarm about Northland emergency managers' reluctance to use tsunami sirens early in a tidal wave warning.

Bruce Young, the Whananaki volunteer civil defence coordinator, said the sirens were in place to warn affected people to seek information during a tsunami threat.

"So why wait? If they're there to alert people to find out what's happening, then let the bloody things off."

Not everyone was glued to a television set or media device and aware a tsunami might be on the way, especially in the middle of the night or if they were outside, he said.


"If you can hear a siren, then you can make your own decisions. It's not going to cause panic and it could save lives."

Mr Young has spoken out about the issue in the past but said it arose at a recent meet-the-candidates evening at Whananaki. Many people said they wanted the sirens as a first, not back-up, warning.

As a result of that meeting, a letter written by Mr Young criticising the current system has been widely distributed.

Tony Phipps, of Northland Civil Defence Emergency Management Group, said a tsunami threat to land was the standard for activating sirens.

"However, the sirens are not activated for a warning level below that, ie, a threat to the marine and beach areas only," Mr Phipps said.

Mr Young said that ignored the coastal population that was most in need of an early alert.

On September 2, a tsunami warning was cancelled more than three hours after an earthquake off eastern New Zealand.

"At no point were the sirens activated even when the reported threat from Ministry of Civil Defence and Emergency Management at 6.59am was for waves between 200mm and one metre likely to affect coastal Northland," Mr Young said.

A one-metre-high tsunami could devastate low coastal areas and endanger many lives, he said.

At 7.13am that day, a ministry email stated the sirens had not been activated because the threat was to marine and beach areas only. It warned people to stay away from the shore areas, listen to the radio and/or TV for updates "and take appropriate evasive action".

Mr Young said the Northland team had to wait for an okay from the ministry to set the sirens off.

"Basically, they're too scared to turn the sirens on because people might think they're crying wolf but if the whole point of having sirens in place is to alert people, well, do it!"

Mr Phipps said the sirens were only one tool within a range of warnings of a potential tsunami.

The systems were tested during the emergency management Exercise Tangaroa only days before the September 2 incident, he said.

"We were satisfied with our ability - when the situation calls for it - to activate the tsunami sirens, deliver information to all of these sources and also test our ability to use the Hazard app as a public alerting system in an appropriately timely manner."