|Feature : Waterways|
|Areas of water including rivers, canals, streams, lake and reservoirs|
Waterways include linear water features such as rivers, canals and streams, as well as water areas such as lakes, reservoirs and docks. Related features include barriers to navigation such as locks, weirs, dams, and rapids.
See Inland navigation for details about navigation of inland waterways and Whitewater sports for details about tagging for canoeing/rafting; also Water management for more details about water managed for human use, including water in pipes, water treatment plant etc and Marine/Marine navigation for information about the sea and navigation at sea.
Please do not be daunted by all the options, just creating a simple way tagged only with waterway=river is a great start; adding a single additional tag is also useful. Leave others to add all the related tags if they so wish.
Linear water features: rivers, canals, streams etc
All rivers, canals and streams should normally be represented as a linear ways. Those ways used should point in the direction of water flow and connect with other linked waterway features to create a routable network.
The main types of natural waterways waterway=river, waterway=stream and waterway=tidal_channel. The main artificial waterways are waterway=canal, waterway=drain. waterway=ditch and waterway=pressurised.
See waterway=* for a precise classification of values and how to use them.
Artificial waterways: pressurised vs Open-flow Waterways
A difference is made between Open-channel flow (free flow) and Pipe flow waterways. river, canal, ditch are open-channel features with different purposes while pressurised is intended to be used where water flows under pressure without air in the conduit, such as in a man_made=pipeline or tunnel=flooded.
Does water flow inside a closed space and can air get inside the conduit?. If yes, the water can't be pipe flow and you'll have to choose for an according waterway=* suitable for open-channel flow.
It is possible that a waterway ends in a sinkhole without meeting another waterway. Using natural=sinkhole and sinkhole=* on a node of the stream, especially on the last one, will then explain to data consumers why the stream vanishes instead of meeting another one
Tidal sections of a waterway can be tagged with tidal=yes and if it is seasonal (a yearly cycle) use seasonal=*. For intermittent sections/areas use intermittent=yes. If a stream starts as as spring, the node can be tagged with natural=spring. The name=* tag is used to hold the name to the watercourse, and wikipedia=* for a link to a related Wikipedia page.
Tagging longer or more complex rivers is done by using multiple successive ways member of waterway relation.
Waterways can have different purposes. Since waterway=* is dedicated to the nature of the water course, it is recommended to use usage=* to give the purpose man made ones.
Here are the appropriate values for water:
This list can be completed as needed.
Wide rivers, lakes, reservoirs and islands
In addition to a linear description of the watercourse, the water surface area for wider rivers can be defined in one of two ways. For rivers, create an area feature for each section (not too long) of the river and tag it as a river area (using natural=water+water=river or waterway=riverbank). Each river areas section should be "glued together" (sharing two nodes or a common way where they are joined).
At certain points along a larger river the area may become a lake or reservoir which can be mapped as such.
Enclosed areas of water for shipping and other craft where the water level can be controlled by lock-gates or similar should be tagged with waterway=dock. It is a matter of judgement sometimes as to where a section of water is a wide river or a long thin lake/reservoir.
Islands in lakes/ponds etc should be tagged with the appropriate landuse=* or natural=* and will ideally be described as a 'inner' area by a multipolygon. Islands can in turn contain lakes and stream etc as well as other features.
Waterfalls, rapids and whitewater sports
For conventions and proposals for mapping waterfalls see waterfalls.
Where a river or stream goes under a road, railway or similar the upper way should be tagged with bridge=yes and layer=1, alternatively tag the watercourse with tunnel=culvert and layer=-1. Where a canal is carried over an aqueduct the way should be tagged with bridge=aqueduct.
- See also Water management
- Waterworks: man_made=water_works.
- Water towers: man_made=water_tower.
- Pipelines: man_made=pipeline and also substance=water or substance=sewage as appropriate.
- Sewage treatment plants: man_made=wastewater_plant.
- Hydroelectric power stations: power=generator and generator:source=hydro.
- Hydrometric measurements of the elevation and the volume ( stream gauges): man_made=monitoring_station in combination with monitoring:water_level=*.
See Coastline for details of how to map the border between land and the sea, together with natural=beach, natural=cliff and natural=wetland to describe the shoreline. See marine navigation, harbour and leisure=marina for features relating to shipping.
- WikiProject Waterways for details of various projects to map particular rivers, or rivers in particular territories.
- WikiProject Whitewater Maps Mapping rivers for whitewater sports