|tunnel = culvert|
|For a stream/drain/ditch passing under a road. Use it on the section of waterway passing under the road.|
|Rendering in OSM Carto|
|Used on these elements|
|Status: de facto|
|Tools for this tag|
A culvert is a device used to channel water. It may be used to allow water to pass underneath a road, railway, or embankment for example. Culverts can be made of many different materials; steel, polyvinyl chloride (PVC) and concrete are the most common. Formerly, construction of stone culverts was common.
Typical culvert is a pipe buried under the road. Very large culverts may be hard to distinguish from bridges. Culverts commonly carry waterway=stream, waterway=drain, and waterway=ditch, but there are also large culverts carrying waterway=river.
How to map
Tag the section of covered waterway, including layer=* as usual for tunnels.
See tunnel=* for a description of the preferred way of connecting culvert waterways to adjoining waterway sections.
Additionally, the following values are in use with waterways: