User @NuSarnia_Demetriushttps://www.openstreetmap.org/user/NuSarnia_Demetrius/history has imported a bunch of data in Sarnia in October 2025. According to the changesets, this data comes from Sarnia Open Data. Per Terms of Use, the data is available under “Open Government Licence – City of Sarnia”, which is not currently an approved OGL variant (this is the usual problem of Canadian OGL variants appending the city name to the license name, see OSMF wiki).
I don’t have energy and patience for cleaning this up, so I favoured a wholesale revert. I raised this with DWG (ticket #2026022510000043) whereupon Clifford Snow @Glassman contacted the uploader (who asserted that license is compatible as “based on” OGL-Canada). Clifford suggested that the license could be approved by LWG and the data cleaned up.
go through all the changesets, fix park names to not be uppercase, merge duplicates where parks were already mapped [2], check if tagging on imported data is good [3]
Or if no one volunteers to clean up, just revert
If doing this, and you have time, might want to also do it for other not-currently-approved OGL licenses listed on Canada - OpenStreetMap Wiki↩︎
the import has some new information like addresses, so optimally it’s not just a matter of deleting the new objects ↩︎
e.g. disused bus stops, parks tagged using addr:full↩︎
I have emailed LWG asking them about using the data from the city. I would suggest holding off any reverts until we get a response. It may take a while since I understand that they are short staffed.
They started importing stuff again. No signs of conflation anywhere. Highways, beaches, pitches and more all mapped as points, often on top of already mapped features. They were also using a custom tool. One changeset added over 1700 businesses all over town with source=survey.
Thank you for the reverts and for pointing me to the import process, both were warranted. I want to apologize publicly for the disruption my edits caused. I started uploading without understanding the Import Guidelines, and the result was exactly what you described: stacked points, no conflation, custom tooling, and source=survey on data that was actually scraped or bulk-imported. That was wrong, and I understand why it had to be undone.
I’d like to do this properly. The data we have for Sarnia (parks, bus stops, road network, speed limits, recreation features, etc.) comes from City of Sarnia Open Data (OGL-Canada v2.0), Ontario Ministry of Transportation public data, and ground survey work by a local team. I believe most of it is licence-compatible with ODbL, and there are real gaps in Sarnia’s OSM coverage we’d like to help close, but only in a way the community is comfortable with.
Is there an experienced Canadian mapper or DWG member you’d recommend I work with as a mentor / sponsor for this import?
I would recommend just documenting your import plans and asking for community feedback as per steps 3 and 4 of the import guidelines. These steps are already there to ensure just that.
Mappers performing imports are expected to be experienced mappers themselves. I would recommend first sticking with just performing regular edits and sticking with well tested tools before attempting to perform an import. Though you could always start a forum thread asking for advice and feedback.
A question for you as well, are you working on behalf of the government, a company, or some other type of organisation? Or is this purely a personal project to improve Sarnia?
Thank you for the clear guidance, that’s exactly what I needed to hear.
To answer your question directly: this is a volunteer civic project, not commercial work. I sit on the Bluewater Trails Committee of the City of Sarnia (committee members list , I’m Demetrius Ribeiro de Paula). The committee assists with the planning, development, maintenance and marketing of Sarnia’s trail network. Separately, I volunteer with nuSarnia (nusarnia.org), a community organisation focused on active transportation, public spaces and people-centred streets. There is no government employment, no commercial vendor relationship, no client paying me, both roles are unpaid volunteer work for the city I live in.
The data sources I’ve been working with are City of Sarnia Open Data, Ontario Ministry of Transportation public data, and ground survey by the local volunteer team.
Your point about earning import credibility through regular editing first is fair, and given the track record I’ve already left behind I understand why it’s necessary. My plan going forward:
No more bulk activity until the LWG decision on the Sarnia OGL variant lands (I understand Glassman submitted that on Feb 26).
Regular one-by-one edits in JOSM/iD to show careful mapping: fix tagging, conflate duplicates, add features the proper way. No bulk tooling, no scripts.
Once the licence is approved and my edit history is reasonable, draft an Import Plan wiki page and post it to the imports list and the OSM Community forum (steps 3 and 4 of the Import Guidelines), then wait the 14-day review window.
Only then any bulk activity, in small reviewable batches under a dedicated _Import account.
If you or another experienced Canadian mapper spots something off during step 2, I’d rather hear it early than wait for a revert.
Two questions back:
On the LWG submission, is there anything useful I can do to help move it along (e.g. provide the City of Sarnia licence text with a diff against OGL-Canada 2.0), or is it best to wait for the LWG to come back to Glassman in their own time?
On my account block, is that tied to the imports question and resolves once I commit to the proper process, or should I expect it to lift only after I’ve built up a clean track record of regular edits?
Thanks again for taking the time. The past month has been a useful reset and I’d rather go slowly and properly than rush again.
Demetrius (NuSarnia_Demetrius)
Volunteer, Bluewater Trails Committee (City of Sarnia) and nuSarnia
