Tsunami evacuation zones and warnings

Are you in a tsunami evacuation zone? You can check Canterbury's tsunami evacuation zones on Canterbury Maps. Search for an address or place in the top right-hand corner.

What to do in an earthquake

If you feel a long earthquake (more than a minute), or a strong earthquake (hard to stand up) leave the RED and ORANGE evacuation zones as soon as the shaking stops.

Do not wait for an official warning, siren, emergency mobile alert, or for someone to tell you to go.

What do red, orange and yellow tsunami evacuation zones mean?

Red zone

The red zone includes beaches, estuaries, harbours and river mouths. These are the areas most likely to be affected by a tsunami and that would experience the highest water depths and strongest currents.  This area can be affected by small tsunamis that are unlikely to flood land but that cause strong surges or currents in the water.

You should leave this zone immediately if you:

  • feel a long or strong earthquake, OR
  • are told to evacuate by Civil Defence, OR
  • you hear tsunami sirens (where they are installed).

Stay out of this zone until you are told it is safe to go back.

You can expect to evacuate the red zone several times in your lifetime.

Orange zone

The orange zone is less likely to be affected by a tsunami and includes low-lying coastal areas that are likely to be flooded in a large tsunami that inundates land.

You should leave this zone immediately if you:

  • feel a long or strong earthquake, OR
  • are told to evacuate by Civil Defence, OR
  • you hear tsunami sirens (where they are installed).

Stay out of this zone until you are told it is safe to go back.

You can expect to evacuate the orange zone maybe a few times in your lifetime.

Yellow zone

Christchurch and Banks Peninsula also have a yellow zone, which are areas least likely to be affected by a tsunami.  They could potentially be flooded in a very large tsunami coming from across the Pacific Ocean.

You do not need to leave this zone if you feel a long or strong earthquake.  There are no known local tsunami sources that would flood this area.

If you hear tsunami sirens, turn on the radio or visit your local council's Civil Defence page.

If you hear or see an announcement by Civil Defence to evacuate the yellow zone, you must leave immediately and stay out of this zone until you’re told it’s safe to go back.

While it is possible you will have to evacuate this zone sometime in your lifetime, it is unlikely.

Note: In most other parts of New Zealand, yellow zones need to be evacuated in a long or strong earthquake. You should check what different tsunami evacuation zones mean when spending time in other parts of New Zealand.

Not in a zone?

If you are not in a tsunami evacuation zone you:

  • don’t need to evacuate in a long or strong earthquake,
  • don’t need to evacuate during a warning from Civil Defence,
  • may wish to open your home to family or friends who need to evacuate.
What should I do if I feel a long or strong earthquake?

If you are in a red or orange tsunami evacuation zone and you feel a long earthquake (more than a minute) OR a strong earthquake (can’t stand up), you should evacuate as soon as the shaking stops.  Do not wait for an official warning, siren, emergency mobile alert, or for someone to tell you to go.

Stay out of the red and orange evacuation zones as a precaution until it can be confirmed there is no tsunami.

 It is your responsibility to decide if you and those with you will evacuate and where you will go. It helps to have a plan. Things you might consider:

  • Where will you go? Talk to friends or family outside the evacuation zones beforehand. Your local council will open civil defence centres but this may take some time.
  • How will you go? Walking or biking can be much quicker than driving as roads get congested.  It is best to leave the roads for those with limited mobility who really need to use them.  Check in advance whether your neighbours need help evacuating. Be aware that if the ground shaking is strong, there may be unstable cliffs and rock falls, so plan your route to avoid these areas, if possible. 
  • What will you take? Have important items ready to grab.
What exactly is a long or strong earthquake?

An earthquake needs to be big to create a tsunami, generally more than magnitude 7.

 A long earthquake shakes for more than one minute. The bigger the earthquake magnitude, the longer the shaking. If the earthquake lasts for longer than a minute, then it's a big one (whether the shaking is strong or mild).

 A strong earthquake shakes so intensely that it is hard to stand up, furniture starts moving around and things fall over.

 If you are near a big earthquake, the shaking will be long and strong.  If you are further away, the shaking may be moderate or mild, but still long.

Check out the Ministry of Civil Defence & Emergency Management’s long or strong video.

How far inland do I need to go if I feel a long or strong earthquake?

You need to be out of the red and orange evacuation zones.

 If you are driving, go beyond the edge of the zones, to make room for those behind you. Walk or bike if you can, to reduce the number of cars on the road. 

Go to friends or family outside of the zone if you can. Although local councils will open civil defence centres, this may take some time.

If you are in a yellow zone, or not in an evacuation zone at all, you do not need to evacuate. You can still choose to do so.

Note: In most other parts of New Zealand, yellow zones need to be evacuated in a long or strong earthquake. You should check what different tsunami evacuation zones mean when spending time in other parts of New Zealand.

Not in a zone?

If you are not in a tsunami evacuation zone you:

  • don’t need to evacuate in a long or strong earthquake,
  • don’t need to evacuate during a warning from Civil Defence,
  • may wish to open your home to family or friends who need to evacuate from a tsunami zone.
What happens along rivers during a tsunami?

Tsunamis can travel a surprising way up rivers – this is called a bore. Even small tsunamis can create strong currents and surges in river mouths. The tsunami evacuation zones go further inland along rivers to take this into account.

Will I get an official warning of a tsunami?

You will only get an official tsunami warning if there is time to issue one.

 If a tsunami is created close to shore, there will not be time. This is why you must move out of the red and orange evacuation zones immediately in a long or strong earthquake - do not wait for an official warning, siren, emergency mobile alert, or for someone to tell you to go.

If a tsunami is coming from further away, an official advisory or warning will be issued, and you will be told which zones should evacuate. Advisories or warnings will be broadcast on television, radio, social media and emergency mobile alerts. Sirens might sound, where they are installed. Emergency services might go through evacuation zones to get people out. You can do your bit by passing information on to family, friends and neighbours.

Contact your local council to see what your local warning arrangements are.

Will I hear sirens?

Tsunami sirens are installed on some parts of the Canterbury coast. They will be activated if there is a confirmed tsunami threat, generally in situations where the tsunami is coming from further away.

If you hear the tsunami sirens, people in red and orange zones should evacuate immediately.  People in the yellow zone should turn on the radio or go to the Christchurch City Council's website to see if they need to evacuate.  If you are not in a tsunami evacuation zone, you do not need to evacuate.

There will not be time to activate sirens for tsunamis created close to shore. These waves can arrive at the shore within minutes - a long or strong earthquake is your warning and you should evacuate red and orange zones immediatey.

Tsunami sirens are not fool-proof and can do more harm than good. In the 2011 Japanese tsunami, many sirens were damaged by the earthquake and didn’t work, and thousands of people died because they waited for sirens instead of moving to higher ground immediately after the earthquake.

 It is up to each district or city council to decide whether to install tsunami sirens.

What should I do if I have to evacuate in an official warning?

If you are told to evacuate in an official warning you may have up to several hours to leave a tsunami evacuation zone.

Things you need to consider: 

  • Take valuables and important documents, as well as clothes, toiletries, medicines and supplies for children and pets. Know where these things are if you need to pack them up quickly. Depending on the impact of the tsunami you could be away from your home for days or weeks.
  • Where will you go? If possible, stay with family or friends outside the evacuation zone. Civil Defence Centres will be opened for people who need emergency accommodation.
  • Secure your home as you normally would when leaving for an extended period. 
  • Check on your neighbours and vulnerable people you know of to see if they need help – Police and Civil Defence resources will be stretched in an evacuation.
  • What is the best route for you to take? In an official evacuation, there will likely be traffic management in place, but you need to have thought about this in advance.
  • Take your pets with you if you can – they are your responsibility. Civil Defence Centres generally will not accept pets, apart from service animals, so you need to have somewhere you can take your pet. Some Civil Defence Centres will have arrangements for pets nearby, so make sure you take pet food, bowls, leash, muzzle and kennel if possible.
  • Residents will be allowed into evacuation zones to pick up family and pets if there is time, provided it is safe to do so before the threat becomes imminent.
  • Schools are required to have evacuation plans for a tsunami and are responsible for evacuating children to the outside of the evacuation zone.
How are the tsunami evacuation zones drawn? What are they based on?

Tsunami evacuation zones are areas that we recommend people evacuate from as a precaution after they feel a long or strong earthquake, or in an official tsunami warning. They encompass many different possible tsunami scenarios.

 The area that would be flooded in any particular tsunami depends on many factors, including:

  • the size of the earthquake
  • precisely how the earthquake fault moved
  • the direction the tsunami is coming from
  • the tide level when the largest waves arrive.

Every tsunami will be different and we can never say for sure exactly which areas within a zone will be flooded. There is no one tsunami that would flood an entire zone.

We consider many different tsunami scenario models when drawing the tsunami evacuation zones. The inland boundary of the zones is based on several ‘worst-case’ scenarios – tsunamis that we might expect once every 2500 years.  

The alternative to this approach is to have hundreds of different evacuation zones for hundreds of possible tsunami scenarios, which would be really confusing and hard to communicate.

The zone boundaries, particularly in urban areas, usually follow some sort of feature that is easy to see on the ground, like roads, so that you easily know whether you are in or out of the zone. We also consider the locations of schools, rest homes and parks.  For example, if part of a park could be flooded in a tsunami, we will generally include the whole park in the evacuation zone, as it is much easier to simply close an entire park, rather than just part of it.

You can download our reports Review of tsunami evacuation zones for Christchurch City (PDF File, 7.09MB) and Review of tsunami evacuation zones for Banks Peninsula and the Kaitorete coast (PDF File, 6.69MB), which describe how the Christchurch and Banks Peninsula zones were drawn and the models they are based on. Tsunami evacuation zones are currently being reviewed in Selwyn, Waimakariri and southern Hurunui using the results of modelling done in 2020.

Tsunami evacuation zones in other parts of Canterbury will be reviewed using the results of modelling being done in 2019 and 2020.

Will the evacuation zones change in future?

Canterbury’s tsunami evacuation zones are based on the best information, including tsunami modelling, that we have at the time.

Our understanding of New Zealand’s tsunami risk is rapidly improving and we plan to continue developing the tsunami models that underpin Canterbury’s tsunami evacuation zones over the coming years. 

We regularly review the evacuation zones and will change them if new modelling shows a significant change in our understanding of Canterbury’s tsunami threat, or if national guidance on the way tsunami evacuation zones are developed changes.

Where do I find specific information about my area?

If you want to know more information about tsunami warning systems in your area, and where to go during a tsunami warning, contact the emergency management officer at your local city or district council. 

Kaikoura District Council 

Hurunui District Council 

Waimakariri District Council

Christchurch City Council 

Selwyn District Council 

Ashburton District Council

Timaru District Council

Waimate District Council


Download reports and documents