Better preparation would have cut the cost of rebuilding disrupted IT systems.
Extreme events such as the Canterbury earthquakes sometimes spark unexpected responses. Unlikely as it sounds, at least one Christchurch company is grateful for the aid it received from the Inland Revenue Department after the firm's computers and paper records were lost.
"Banks and the IRD were able to come to the rescue because they held a lot of information that was critical to individual businesses," says Peter Townsend, chief executive of the Canterbury Employers' Chamber of Commerce.
"For example, banks that had done a company's payroll in the week before the February 22 quake could just roll it over the week after. That sort of support was really crucial."
Townsend says he knows of no firms that were put out of businesses because of quake disruption to their IT systems, but plenty were seriously disadvantaged.
"I know of a lot of businesses that had to reinvent their systems, and that is really expensive, time-consuming and disruptive."
If the quakes caused untold damage and loss of life, they also imparted several IT backup lessons. Foremost, says Townsend, is that organisations need to ensure that if their computer system is on the premises, data and applications must be mirrored at a remote site.
He says multiple copies of vital records - both digital and physical - need to be kept and available from anywhere. And a backup plan is essential.
Many Christchurch law firms are still unable to get access to deeds, wills and other documents, but Townsend says if they had been IT-savvy, documents would have been scanned and digital copies stored in a secure location.
"There were literally bundles of wills put into wheelie bins by rescue squads and carted out and craned down the sides of buildings, then taken away for sorting. It's been a huge recovery effort and I think that's a really valuable lesson.
"I had one case of a lawyer contacting me to ask whether he could land a helicopter on top of one of the city's broken buildings so he could sneak in and recover a computer server. I said no, but that's how desperate people were."
Another valuable IT lesson is the importance of making sure staff can stay connected at all times. That implies more than just being able to remotely access a work server, the usefulness of which is limited in a power cut.
What it highlights, Townsend says, is the inherent resilience of cloud computing services, in which data and applications are hosted by a third party that could be at the other end of the country.
"There were a lot of people wondering whether they should have a remote backup server or they should get into the cloud who now have a compelling case for doing so."
Townsend says reliable connections aren't just important for computers.
"One of the things we discovered after February 22 in particular is the absolutely critical nature of text messaging and communicating with staff by text.
"That was one of the only means of communicating, post-earthquake, and it was a really powerful way of staying connected. So having text trees, having a predetermined plan for communicating with staff, is critical."
After the first big quake in September 2010 the Chamber of Commerce joined forces with the Canterbury Development Corporation to create the Recover Canterbury group, which built a website that became the point of contact for businesses needing assistance.
"One of the rules of the website is that it would not contain any information that was not directly relevant to the business community, giving us a very uncluttered electronic capability that has lasted more than 18 months and is still doing a great job. It became an extraordinarily powerful tool."
Even after the first quake struck, Townsend says, some businesses didn't take the hint that off-site system backup was essential.
"There were companies that had their IT on site that decided after surviving the September quake they would leave it where it was. Then along came February 22 and, whammo, they got smacked up again and lost their IT capability.
"The important lessons learned from these earthquakes - that having off-site capability and backup is fundamental and so easy to do now - need to be applied right across New Zealand.
"Before the earthquake the cloud was considered a little risky because you didn't have complete control over your IT, but we've got beyond that."
Townsend will be taking the stage at a business continuity conference in Wellington on April 18.
One of the things he tries to get across to people who haven't seen the quake damage first-hand is the scale of the disaster. And as the $30 billion rebuild gets under way, he emphasises that Christchurch will not be attempting to return itself to the way it was.
"We're not, we're going somewhere completely new, and that applies to IT as much as it applies to anything else."