Relation:waterway

The purpose of a waterway relation is to have a single object describing the entire course of a river or other waterway. Most tags can be added once to the waterway relation instead of being added and maintained on each segment. The relation includes all ways that make up the river, including side streams such as anabranches or distributaries . Doing so allows data consumers such as Nominatim to group the ways together and return exactly one named result per named waterway that exists in OpenStreetMap.

Each way must be tagged with waterway=*, and can also have additional tags describing the individual way (e.g. intermittent=yes, width=*, ...). Tags describing the waterway as a whole should go only on the relation (e.g. wikidata=*, destination=*, ...), except for the name.

The relation should obviously be tagged with name=*, as well as name:*=* for names in other languages. However, because not every renderer supports waterway relations, each waterway should also be tagged with the local name=*. Short segments may have different names (e.g. a section of rapids) or no name (if it passes through a lake), and these can be tagged accordingly. Also, the local name of the waterway may change as it passes through different countries or regions that speak different languages, in this case tagging each way with the local name becomes more important, and the relation should have an appropriate mutlilingual name.

Tags

Key	Value	Description
type	waterway (mandatory)
waterway	river, stream, canal, drain, ditch (mandatory)	Subtype of the waterway relation similar to waterway=* Hint: if the waterway starts as a stream and becomes larger, then use the tag of the largest waterway (e.g. river). This is purely informational, the relation members still need their own waterway=* tag.
name	* (mandatory)	Name of the waterway. When a waterway has multiple names (e.g. because it passes through multiple language regions), use all different names in the name tag, ordered from source to mouth, and split by slashes (the character "/"). The individual relation members can still have their local names.
name:<xx>	* (optional)	Name of the waterway in the specific language, where xx is an ISO language code. See: Multilingual names. The English name tag name:en=* is recommended for large waterways or when the name tag is in a language not every people can read/sound it (Chinese, Japanese, Russian, Khmer...).
destination	* (optional)	Name of the river, lake, sea, ocean... into which this waterway flows.
wikipedia	* (optional)	Link to the wikipedia page (when several pages in several languages are available, choose the page with the best/complete description).
wikidata	* (optional)	ID Qxxxx of the waterway in Wikidata
intermittent	yes (optional)	Add if the presence of water is not permanent.
length	* (optional)	Total length of the waterway in meter. To avoid. The information is or should be in wikipedia and/or wikidata. To have the information in different places means probably different values.

Reference tags

Key	Value	Description
ref	* (optional)	Any kind of reference or use the specialized tags below. (See discussion for more alternatives)
ref:sandre	* (optional)	In France you can add the Sandre reference: see French waterways wikiprojet for explanations. Sandre official Website or fr.wikipedia
ref:fgkz	* (optional)	In Germany you can add the FGKZ reference
ref:regine	* (optional)	In Norway you can add the regine reference
gnis:feature_id	* (optional)	In USA you can add the gnis reference
ref:gnbc	* (optional)	In Canada you can add the gnbc reference
ref:gwlnr	* (optional)	In Switzerland you can add the gwlnr reference

Members

Object type	Role	Recurrence	Description
	None or main_stream	One or more	Any kind of waterway ways. They must have a waterway=[river, canal, stream, drain, ditch] tag.
	side_stream/ anabranch	Zero or more	A branch of main stream that returns to it. They must have a tag waterway=*.
	spring	Optional	natural=spring The spring of the river.
	mouth	Optional	The place where the river ends. Could be the junction with another river, a sinkhole...
	tributary/ distributary	Zero	A watercourse (tributary) can join another watercourse, or a watercourse can split into two different watercourses (distributaries). If needed, use queries to gather tributaries of a watercourse (example). To avoid. Misleading, mixes up data about separate watercourses, see Talk:Relation:waterway. If it is truly two different watercourses, don't mix them in one relation, or if it is the same watercourse (example, a river in a delta before to end into a lake or a sea), use the role side_stream.
	riverbank or waterbody	Zero	The waterbody (area) of the river. To avoid. Not approved and controversial, see Talk:Relation:waterway. The purpose of a waterway relation is not to have a collection of all elements of a watercourse but to put together elements to avoid redundant (and missing) informations on all the ways of the watercourse.

See also

• The proposal Relations/Proposed/Waterway

Related pages

• WikiProject_Rivers to organize waterway mappings
• waterway=* - for mapping single waterways
• water=* - for mapping waterbodies

Tools

WIWOSM

displays rivers in wikipedia maps

Scanner for waterway relations

“OSM Waterway analyses”. http://www.h-renrew.de/h/osm/osmchecks/07_watershed/index.html. 

Statistic for waterway related relations

“OSM Relation Hierarchy: planet_waterways”. http://www.h-renrew.de/h/osm/osmchecks/02_Relationstypen/planet_waterways.html.  (outdated, datas are from 2010 to 2013)

Overpass Turbo query to display the tributaries of a given river

https://overpass-turbo.eu/s/PFD