One of our 2025 new year’s resolutions was to restart our long-running interview series with OpenStreetMap communities around the world,and I am delighted to share that we are kicking that effort off today with an interview with Amanda McCann, maker of WaterwayMap
1. Who are you and what do you do? What got you into OpenStreetMap?
I’m Amanda McCann. I’m a queer trans woman from Ireland, who’s been living in Karlsruhe, Germany for 10+ years, working at Geofabrik, as a sysadmin. In my free time, I like hiking.
I have always been interested in open data, open source/free software, and a bit in maps. I got interested in OpenStreetMap in 2008. The “open data” aspect appealed to me, and it’s just fun! I’ve been hooked every since. The anarchistic free form nature keeps me interested. I’m always blown away by how good and wide and deep our data is, and how we’ve managed to do that by mostly staying small without hundreds of employees. I’ve been around OSM for years, spoken at conferences, helped organise events, been on the OSMF Board, and Communications WG.
The easiest way to contact me is on Mastodon/Fediverse: @amapanda or email: amanda@technomancy.org
Editor’s note: we would be remiss not to also mention that Amanda is a past #fridaygeotrivia winner, having taken home the emoji trophy back in November 2023!
Here’s a photo of me at the source of the Danube
2. What is WaterwayMap and why did you create it? Who uses it?
WaterwayMap.org is a map of waterways (rivers etc) from OpenStreetMap. Uniquely, it groups connected rivers together, colouring them the same, showing river networks. It also calculates downstream flow, and can draw rivers with more flow wider, producing maps like traditional maps of rivers. This allows the production of good maps, and the finding of errors in the data. All of this is calculated automatically from 100% pure OSM data. It also calculates some QA maps, such as loops in rivers in OSM. I initially wrote a tool (osm-lump-ways) to group roads with the same name together. I tried it with rivers, and it produced something that looked nice. I shared this with OSMers, and it was very well received. This was very encouraging, and I didn’t see anyone doing anything like this. So I got “swept along in the current”.
It’s mostly used by OSMers to look at the OSM data, but in a new way. I want to produce more details on individual rivers, so it can be a global internet resource.
3. What are the unique challenges and pleasures of mapping waterways in OpenStreetMap? What aspects of the projects should the rest of the world be aware of?
Most challenges are standard OSM data processing challenges, e.g. OSM is 99.9999…% correct, but not 100%. WWM is essentially a breath first search of a directed graph. Lots of graph processing algorithms require (e.g.) zero cycles in the graph. If you don’t remove them all, then the standard algorithms don’t work. So if you assume OSM data has zero errors, you’ll have problems. Lots of the algorithms don’t work very well parallel, because the whole world is connected together.
Since the map groups everything that’s connected together, a tiny little misttagged way somewhere can turn half a continent a different colour. That’s a unique problem!
It’s very enjoyable to slowly see a river network come together, and the data to be cleaned up. Since I started, so many OSMers have cleaned up the data (& continue to clean it up!). It’s also very cool to be able to load QGis and create a map that is visually very pleasing.
4. What is the best way for people to get involved?
Look at an area that interests you, see if the map(s) on WWM make sense, and if not, then edit OSM to make it correct! That’s the same as lots of “how to get involved in OSM” All the code & website is open source so if you think it’s classifying different tagging combinations wrongly, then open an issue. You can also use the same process to generate data, for your own area if you want.
I’d love people to make their own maps (e.g. with QGis) with the data that I generate.
5. What steps could the global OpenStreetMap community take to help support the mapping of waterways?
Nothing special, just map things well and as best as you can. Connect up ways. Check out WWM to see the results of your mapping.
6. Last year OpenStreetMap celebrated 20 years. As someone who has been very active in OSM in so many ways (mapper - in different local communities, software developer, on the OSMF board, etc) for a long time, where do you think the project will be in another 20 years?
Oh that’s a hard one! I’m terrible at making predictions!
I think the strength of OSM has come from it’s community of mappers who *care* about making a map. Throughout the years, I’ve seen many groups saying that is silly and we need to completely change to imports, or AI or whatever. Many of those groups have gradually realised that the “old fashioned” crowd sourced map approach seems to work best, and have moved towards doing that. So I have hope that we’re actually onto something right.
So my maybe optimistic prediction is that OSM in 20 years will look sorta like now. Craft mappers crowd sourcing a map! We’ll have more mappers, and more data, and the average amount of data will increase.
Thanks so much, Amanda. For the interview, for creating WaterwayMap, and for all your efforts for OpenStreetMap. I encourageeveryone to have a look at WaterwayMap, and of course dive into making corrections as needed.
The best way to stay informed about new WaterwayMaps developments is via social media
Happy waterway mapping,
Please let us know if your community would like to be part of our interview series here on our blog. If you are or know of someone we should interview, please get in touch, we’re always looking to promote people doing interesting things with open geo data.