OPINION: About 1am on Monday, not long after the 7.8 quake, when I had cleaned up the glass in my kitchen, inspected the cracks in my wall, and filled up as many containers as possible with fresh water, I settled down in my doorway to get to work.

A colleague had already set up our live blog, but the news was getting to be too much for one person to handle. There was an effective communications blackout with the worst-hit areas, hundreds of students wanted to know about their NCEA exams, and we had no idea if the continuing aftershocks were going to slow down any time soon (hence the doorway). But at least there wasn't a tsunami threat!

Soon, of course, there was, for the entire southern coast of New Zealand. Then it was the entire southern and eastern coast. Then the East Cape down to Southland, but somehow also Kapiti.

KIRK HARGREAVES/FAIRFAX NZ For a time that Monday morning, chaos reigned. It didn't have to.

It was an extremely long night, and much of my time was spent demystifying the continous mixed messages from the authorities we trust to know what they are doing.

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If you weren't awake, let me give you a quick idea of the confusion.

Alissa Walker A Japanese or Mexican style alert system would be great. For now, we need a Band Aid.

National Civil Defence was warning Kiwis in coastal low-lying areas to get to higher ground from a bit after 1am. It was not clear how one exactly defined "coastal" or "higher ground" - for that you had to check in with your local civil defence group.

@Harrysm48103937 Sorry, we don't cover Whakatane! Contact your local civil defence for info — WREMO (@WREMOinfo) November 13, 2016

Here is where things really got messy. Each civil defence area has its own website, own social media channels, and own way of doing things.

In Wellington, the warning for eastern coastal areas slowly developed into a warning for the Kapiti and Hutt areas too. Sirens started going off in Lower Hutt and people from all over the place rushed to higher ground.

Many in Wellington's coastal communities drove to the summit of Mount Victoria - far far higher than they needed to be - causing significant gridlock at a time when clear roads were desperately needed.

All the while almost all of these people were safe to stay in their homes. The warning, as it was clarified around 3am, applied only for the "red areas" in Wellington's tsunami zone.

The red area basically only applies to the beach. It doesn't cross the Petone Esplanade, or get very far at all into Island Bay. As a spokesman for the Wellington Emergency Management Office said at the time, "people in low lying suburbs do not need to go to higher ground".

This was almost the exact opposite of what national civil defence were saying.

@WREMOinfo can you share image so it can be shared wider? Your site being hammered — David Ross (@sw1ayfe) November 13, 2016

It was also extremely hard to interpret, because the only way to check on whether you were in a red zone was to load a low-res PDF map of your area from the Wellington site, or fiddle with a cumbersome mapping system which wouldn't keep the red zones visible if you zoomed in past a certain point. The website was slowed to a crawl with the strain from everyone trying to load it, and we were still getting wildly conflicting reports on whether or not those on the Kapiti Coast should be evacuated.

Evacuation for Wellington for red zone only. See map for details. #eqnz pic.twitter.com/FCozE9DYYd — Grant Robertson (@grantrobertson1) November 13, 2016

And Wellington was one of the better ones. Some areas don't use a zone system. Many areas only have cumbersome and mobile-hostile PDFs. Canterbury had a full software mapping system, but I couldn't load it once all night.

This resulted in unnecessary panic and confusion. About half of all the comments we received on the blog were from terrified residents asking me whether they needed to evacuate. Many left their cellphone number and asked that I text them as they drove as far inland as they could get. Some were tens of kilometres from the sea but had no idea how safe they were. I did my best to help - that's my job - but it's also the job of our Civil Defence systems. And they were woefully ill-prepared to deal with the load.

I don't fault GeoNet for a bit of early confusion over whether or not a tsunami was possible. Science is hard and it seems there might have been just one staff-member on call.

But the Civil Defence web situation was an abject mess. Why on earth does each region get to manage its own web presence? Why can't the servers deal with a large burst of traffic - surely a likely scenario for an emergency information website? And why would you use PDF maps, which are large and perform poorly on smartphones? Yes, these PDFs might make sense for people who prepare by printing stuff out, but that is not most people.

Many others have complained about the tsunami system mess, and Key has already indicated the Government is working on a Japan-style mobile alerts system, where everyone's smartphone is taken over by a loud siren if they are in a certain area.

Good on them, but that kind of system will take months to build. In the meantime, a national tsunami map database needs to be set up - one that works well on smartphones, one that can take the strain of every Kiwi in a vaguely coastal area trying to load it at once, and one that at a most basic level can tell someone whether or not they need to get out of their house. There are hundreds of free and reliable web mapping tools that could achieve this.

We should get to work on this immediately, while the hard work on the Japan-style alert system gets underway. The stakes are far too high to rely on PDF maps hosted on a server used to a few hundred visits a day. Get to it.