Tsunami evacuations: What went wrong?

A report on the failed Christchurch tsunami evacuation in November has found failings in the way it was managed.

It found the information given to the public was inconsistent, a Police evacuation plan for coastal suburbs had not been made public, and the Civil Defence team in charge of sending out the warning was getting information too late.

Hundreds of people were trapped in traffic for more than an hour trying to leave coastal areas around New Brighton, which would have left them in danger if a tsunami had hit and swept up the estuary.

The report found Canterbury Civil Defence, which is supposed to lead and direct an evacuation, was consistently receiving and issuing warnings too late.

Local Civil Defence groups are responsible for issuing tsunami warnings in their area.

But the review found both Police and media were alerted and were warning residents to evacuate before the local Civil Defence teams were told.

The 70 page report also details a timeline of communication from the time the earthquake struck at 12.02am.

It details text messages from Mayor Lianne Dalziel, to council staffers.

It shows that the Ms Dalziel was listening to Radio New Zealand and was confused between messages from the Ministry of Civil Defence Emergency and those in the media.

One text message said at 1:13am from Ms Dalziel to  to city council general manager customer and community Mary Richardson – “Radio NZ are dreadful – here’s the CD website http://www.civildefence.govt.nz – who has to move? Are we using the Tsunami sirens?”

Police also contacted the city council, confused between the MCDEM and CDEM messages. The timeline noted a telephone call from Police district communications centre to the city council call centre at 1.30am.

“1:30am Police asked if CCC was asking residents to evacuate. Advised no CCC was not asking residents to evacuate because information received from MCDEM advises it’s only a marine and beach threat.”

Problems with tsunami sirens

The earthquake hit at 12.02, but the tsunami warning sirens were not activated until 2.01am.

The report found Christchurch Civil Defence staff had not activated the sirens themselves before, and had to call the system supplier in Auckland to do it.

However, the supplier activated them within four minutes of recieving the call.

It found one of the 45 sirens failed because the battery was dead, which the city council had known about and had been working before the earthquake to fix.

The review also found the switches on the sirens were known to be faulty but had not been replaced – but the parts did not fail when they were sounded.

They are now being replaced, and will be serviced this year.

Evacuation plan not released

Christchurch Police had a coastal areas evacuation plan in place for more than 10 years, but it had not been made public so most people did not know about it.

The report said the police had limited resources to implement the plan, and “may not be able to reach the evacuation zone within the time frame available” to carry it out.

A map was available on the city council website with instructions for what to do after a distant source tsunami warning where there was a lot of time to evacuate, but there was no map for local or regional tsunamis.

The review found police were warned and started evacuating residents before local Civil Defence teams were told, and they also began letting residents back into their homes before local teams had officially cancelled the evacuation.

“It appears the [police] deputy commissioner in Wellington has access to information from MCDEM earlier than the information being issued by MCDEM to CDEM groups,” the report said.

Key recommendations:

  • Emergency Operations Centre systems and processes need to be reviewed to ensure that there is absolute clarity with respect to who has overall responsibility for the EOC; who is responsible for each components.
  • The CDEM team should liaise with Christchurch Police and Group to discuss establishing an evacuation register as part of an existing civil defence website.
  • A campaign should be undertaken to enlist more civil defence volunteers.
  • Before communication is issued to the public regarding the opening of welfare centres, the CDEM team need to identify which facilities are appropriate, chekc they are outside the evacuation zone.
  • EOC staff who are called in should be well trained.
  • Staff should only be required to work for a reasonable 23 period of time, be provided healthy food and given time to rest and recover.
  • There should be a sufficient number of EOC staff to enable fresh staff to take over at the end of a shift.