Did you know that a tsunami can travel at up to 800 kilometres per hour in open water? Yes, that’s eight hundred. And far from being a really really big wave, it’s a wall of water with a speed and force that’s almost incomprehensible. Anyone who’s ever seen the videos of the 2011 tsunami that hit Japan could not fail to understand the power and force of that wall of water as it washed ships ashore, carried houses away and crumbled buildings.
Here in New Zealand we’ve recently had a few almost false-alarm tsunami, less than a metre in height. They may make us complacent, feeling that a tsunami isn’t a big thing. But if a really big earthquake struck nearby we could face something quite terrifying.
The thing is, there could be little to no warning. That’s why the advice is:
… move immediately to the nearest high ground or as far inland as you can if you are at the coast and you experience any of the following:
- feel a strong earthquake that makes it hard to stand up, or a weak rolling earthquake that lasts a minute or more
- see a sudden rise or fall in sea level
- hear loud and unusual noises from the sea
Source: Horowhenua District Council.
So, where do you go? Well, first and foremost, higher ground — a bit in short supply near here.
Next, drive away from the beach along Waikawa Beach Road. The Council have now marked the road with a Tsunami safe zone blue line to show the maximum probable extent of inland inundation. That line is 1 Km west of Takapu Road. But don’t stop there — leave room for others behind you and go further up the road. The school at Manakau is our local civil defence centre.

Keep in mind that the water will follow the path of least resistance: it’ll rush in through breaches in the dunes, and up the river and surely swamp the low-lying land that floods every time there’s a big fall of rain.
When you leave take your emergency bag with you and your pets, if you can. Do you have a neighbour who may need help? We’re a community who must rely on one another.
Last year the Council put signs near the beach with information about coastal hazards. Take a minute to read one next time you pass.
