Queensland flood maps: building a database in times of crisis

It wasn’t until Toowoomba disappeared underwater on Monday that I thought I should probably see if my house was at risk. I wasn’t the only one though; the Brisbane City Council website was suffering under heavy activity and was refusing to load.

What I was looking for was a file I had stumbled across about a month earlier: a suburb flood flag map. That evening I asked Twitter if anyone had the map for my area: New Farm. I eventually discovered I still had it on my drive but, by that stage, others had asked me to let them know if I find it. To help others, I put up a web page on my server on late Tuesday night with the handful of files I was able to find. I then told people on Twitter and Facebook where to find the page and went to bed.

A couple of years ago, the Brisbane City Council had the bright idea of putting together maps for every suburb that show where water is expected to flow under heavy rain conditions. For example, my next-door neighbour’s property won’t flood but she can expect to have quite a lot of water run through her backyard. The bottom of my street will flood but, as I’m on a hill, it won’t reach as high as my house.

It’s the sort of information that can help you make decisions like finding out what roads to use to get home (or to get out) when some roads are already covered in water.

Early on Tuesday morning, others contributed some more of the maps and I was able to pry some more from the Brisbane City Council’s flailing servers. I posted them on my page and reminded people they could access them there.

It spread like wildfire. Thousands of people shared the website address with their friends, who shared it with their friends, and so on. Google’s search engine had picked it up, too. By midnight on Tuesday night my humble page had helped 199,833 people.

Brisbane’s flood zones SOUTH (top), EAST (middle) and WEST (bottom).
Individual suburb maps are available here.

But there is still a lot to do. I’m now trying to update with newer information, such as sandbag locations, updated flood projection models and a list of evacuation centres. Thankfully, everyone in Brisbane has been supportive, supplying links to data or emailing it to me when those other sites are down.