OSM coverage gaps over time

How many City of Guelph stormwater basins are still missing from OpenStreetMap or mapped as plain water, and how many named creeks still run unnamed in OSM — one point per weekly comparison, so a mapper can see the worklist shrink.

1 comparisons since 2026-10-09 · 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 polygons); the rest were observed by the weekly build. Counts follow the City's basin layer, so they move when the City adds a basin (about one a year), not only when someone maps one.

Every comparison

Built by guelph-maps/guelph-water-layer. OSM data © OpenStreetMap contributors. Contains information licensed under the Open Government Licence – City of Guelph.