Many of us have said since Katrina that when the US federal government says you have to be prepared, they must have an inkling the preparation is necessary – whether it is because they are anticipating a catastrophe or just realize they are powerless to help in the aftermath.

But when the wealthy start making plans for a survival escape, it might be time to start asking them why.

The world of Doomsday survivalists or ‘Preppers’ — those preparing themselves for total social collapse — is usually associated with wild-eyed eco-beardies hiding in the woods.

Nuclear war is just one of the fears driving the billionaire ‘refugees'

But the existence of a very different group of Preppers was laid bare by a political row in New Zealand this week.

Attracted by a remote First World country that has the potential to be self-sufficient and is on no one’s list of nuclear targets, the super-rich kings of

Silicon Valley and Wall Street are buying up vast tracts of its land — in anticipation of the day when they may need to live there.

The controversy has revealed the extraordinary precautions being taken by the mega- rich to ensure that WTSHTF — a crude survivalist acronym for ‘when the **** hits the fan’ — they and their loved ones will be safe and comfortable.

What the catastrophe will precisely be remains unclear, but possibilities include a devastating asteroid impact, giant earthquake, nuclear war, civil war, pandemic, zombie invasion and the Second Coming.

Tellingly, the geeks of Silicon Valley appear to be most worried that it will be a struggle between rich and poor in a world economy turned upside down by new technology — with them as the main targets.

Local estate agents say their U.S. clients rarely intend to live in New Zealand, but cite reasons for their purchases such as the toxic presidential election and the spate of mass shootings in America.

In the first ten months of last year, foreigners — mainly Australians and Americans — bought nearly 1,400 square miles of land there, more than four times what they bought in the same period the previous year.

When they’re not buying up land abroad (Chile is also popular as it has low taxes, a good climate and good air links), rich survivalists like to swap tips on private Facebook groups or at regular dinners.

Popular subjects range from buying internet currencies such as Bitcoin, as protection against a central banking meltdown, to which foreign countries are most likely to hand them a passport and so the chance to relocate there in a crisis.

Some have planned for every eventuality. Steve Huffman, the 33-year-old co-founder of the internet discussion forum Reddit, which is valued at $600 million, is one of several Silicon Valley barons who has had laser surgery to correct poor eyesight.

But why are the country’s most privileged people, protected by immense wealth, quite so in fear?

For it is believed that at least 50 per cent of Silicon Valley billionaires have taken out so-called ‘apocalypse insurance’ by finding a refuge at home or abroad.

Reluctant to admit the truth, they often describe it as a holiday home, so it’s difficult to know whether or not Facebook founder Mark Zuckerberg bought a 750-acre estate in Hawaii ‘just in case’.

Similarly, his fellow tech billionaire Larry Ellison, founder of Oracle, who has not only bought 98 per cent of Hawaii’s sixth largest island, Lanai, but — handily — its own airline.

Of course there is the possibility that these fretting tech wizards’ prescience is justified. For many have made their fortunes out of predicting mankind’s dependence on digital gadgets and so we should respect their Doomsday hunches.

Survivalists say the first signs of crisis often appear on internet chat forums, as they reportedly did before the 2008 financial crash.

Yishan Wong, another Silicon Valley multi-millionaire who has had eye surgery in readiness for a world without opticians, argues that techie types see risk in a clear-headed way. An apocalypse may be a remote possibility but, if you have money to burn, it’s ‘logical’ to take out insurance, he says.

A less flattering theory is that they’re simply bored nerds who long for adventure and fantasise about a future in which they’ll be a woman-magnet cross between apocalyptic hero Mad Max and environmentally friendly chef Hugh Fearnley-Whittingstall.

A New York architect told me he was hired by a senior partner at the bank Goldman Sachs to build a post-Apocalypse house far outside the city. His client wanted it to be a rallying point for local people, gathering — of course — to fall into line under his leadership.

For these great Silicon Valley egalitarians fear that if society collapses, vengeful mobs will look for the super-rich. And, in particular, for the tech wizards whose robots and artificial intelligence systems are taking humans’ jobs.

A critic might ask why, if they’re so alarmed by a battle between rich and poor, they don’t stop wasting their billions on stockpiling armouries and islands and spend it helping the less fortunate?

But then what sort of red-blooded tech king wants to sign a cheque to charity when they could splash out on helicopters, Ducati motorbikes and an assault rifle for every family member?

It’s easy to laugh at the obscenely rich finding grotesque new ways to waste their money. But it’s undeniably disconcerting when it’s the lords of our digital age.

After all, everyone in Silicon Valley claims they want to save the world, not run away from it.

There are several take away points us “normal” folks can run with from this article.

First, it is not abnormal to be wary of the future, especially as it pertains to survival incidents – even the billionaires think something is up. Second, their preparations are not much different than most of us – they just are grander and cost more. Third, they, like us, do not seem to have a clue as to what might hit us – just that the possibility is very good something will.

To read up on this trend of rich guys buying up remote places, check out the UK Daily Mail.