OSM coverage gaps over time
How many City of Guelph hydrants are mapped in
OpenStreetMap, how many of those still lack their type or
position, and how many OSM hydrants sit nowhere near a City
one — one point per weekly comparison, so a mapper can see the work
move. The table has every count, missing included.
2 comparisons since 2026-06-01 · last 2026-10-09 ·
current gaps · data (JSONL)
Points in the shaded span are reconstructed after the fact from OSM's own
history (an Overpass attic query for that date, compared against today's
City hydrants); the rest were observed by the weekly build. Counts follow
the City's Hydrants layer, so they move when the City adds or removes a
hydrant, not only when someone maps one.
Every comparison
| Date | Missing | Far | Duplicate |
No type | No colour | No position | OSM only |
Matched | City hydrants | OSM hydrants | Source |
|---|
| 2026-10-09 | 3,391 | 6 | 1 | 16 | 14 | 83 | 3 | 140 | 3,537 | 150 | live |
| 2026-06-01 | 3,434 | 6 | 1 | 16 | 14 | 83 | 2 | 97 | 3,537 | 106 | reconstructed |
Built by guelph-maps/guelph-hydrants-layer.
OSM data © OpenStreetMap contributors.
Contains information licensed under the Open Government Licence – City of Guelph.