A tagging cheat sheet for the infrastructure a water/wastewater engineer actually notices on the street, plus a small Overpass QL builder for querying what's already mapped. Runs entirely offline; the query builder persists in this browser via localStorage.
note=*, and let the local community weigh in. Also: never copy from Google Maps, county GIS with restrictive licensing, or as-builts you don't have the right to publish — OSM requires compatible sources (your own survey, Bing/Esri imagery where permitted, open-licensed data).
| Feature | Core tags | Useful extras |
|---|---|---|
| Fire hydrant | emergency=fire_hydrant | fire_hydrant:type=pillar/underground/wall, colour=*, ref=* |
| Manhole (sewer) | man_made=manhole + manhole=sewer | ref=*, operator=* |
| Manhole (storm) | man_made=manhole + manhole=drain | ref=* |
| Water valve (surface-visible) | man_made=valve | substance=water, location=underground, valve=gate/butterfly |
| Water tower / tank | man_made=water_tower / man_made=storage_tank + content=water | height=*, operator=* |
| Covered reservoir | man_made=reservoir_covered | operator=* |
| Well | man_made=water_well | pump=yes/no |
| Pump / lift station | man_made=pumping_station + substance=water or sewage | building=* on the structure, operator=*, name=* |
| Treatment plant (wastewater) | man_made=wastewater_plant (area) | operator=*, name=* |
| Treatment plant (drinking water) | man_made=water_works (area) | operator=*, name=* |
| Pipeline (where mappable) | man_made=pipeline + substance=water/sewage | location=underground, diameter=* (mm) |
| Open channel / ditch | waterway=ditch or waterway=drain (lined/urban) | tunnel=culvert + layer=-1 where it crosses under |
| Culvert crossing | the waterway way gets tunnel=culvert, layer=-1 | never break the waterway — it flows through |
| Retention/detention basin | landuse=basin + basin=retention/detention/infiltration | intermittent=yes as applicable |
The valve row above shows the honest state of things: some utility features have settled tags, others are still contested — which is exactly why the wiki check matters. Anything not surface-visible and not open-licensed generally shouldn't be mapped at all.
key=value; multiple values use semicolons (ref=A;B) but sparingly — separate features usually beat semicolon lists.construction:man_made=pumping_station (being built), disused:* (intact but unused), abandoned:*, demolished:*. A facility under construction should never carry the live tag — routers and data consumers believe you.source=survey / source=local knowledge on the changeset; note=* talks to other mappers; fixme=* flags known problems.ref=* is the bridge between OSM and the utility's asset IDs — enormously useful, but only where the ID itself is publishable.Paste into overpass-turbo.eu and Run. The query asks for nodes, ways, and relations with the tag inside the bbox, and returns geometry.
Hydrants in OSM have genuine emergency-response value and are unambiguous street furniture. Manhole covers are honest, surveyable, surface-visible facts — and a mapped pattern of sewer manholes is a legitimate public record of where public infrastructure runs, assembled from what anyone can see from the sidewalk. The line to respect: surface-visible features observed in person are fair game; buried alignments, depths, and anything from restricted as-builts or licensed GIS are not — both for licensing reasons and because publishing detailed utility data you hold in a professional capacity is a professional-judgment question before it's a mapping one.
The generated query is the template worth memorizing: nwr[key=value](bbox);out geom;. Variations: ["key"~"regex"] for pattern matching, multiple filter brackets AND together, around:50,lat,lon instead of a bbox for proximity, and out count; when you just want numbers. The Overpass Turbo wizard writes decent queries from plain English if the syntax fights back.