| +/- natural=water
Used to mark body of standing water, such as a lake or pond.
Used to tag an area of water. The type of water body can be specified with water=*.
How to use
This tag can be placed on an area (i.e. a closed way) for a simple lake, or it can be placed on a Relation:multipolygon if the lake either contains islands or has a large coastline (but not big enough for natural=coastline).
- Draw or select a closed way around the perimeter of the lake. It doesn't matter which way around the way goes. (JOSMs validator plugin actually (still) complains about anti-clockwise ways.)
- Tag the way it with natural=water and maybe a name=*.
- For a lake, add a tag water=lake.
Creating islands in lakes
To create islands in a lake, the lake should be a Relation:multipolygon.
First create the lake:
- Draw or select the way around the perimeter of the lake.
- Create or select a Relation to serve as the lake.
- In Potlatch: the chain-like button just above the tag button accesses relations. It lets you create a new relation or add the way to an existing relation. Relations are listed as properties of the ways just like tags. Clicking on the left part of the relation accesses the relation's tags, and the right part accesses the tag's role in the relation.
- Tag the relation with type=multipolygon, natural=water, name=*, etc. Redundant tags should be removed from the way.
- Add the way to the relation and set the role to outer.
Then carve a hole in the lake by adding the island as an inner ring:
- Draw or select a way around the perimeter of the island.
- Tag the island as appropriate with natural=*, name=*, etc. If natural=* is missing, the island will assume the natural-type (e.g. wood) of the land surrounding the lake.
- Add the island to the lake relation with the role of inner.
Creating lakes on islands
- draw a way around the lake
- tag it natural=water
Automatic water mapping
- scanaerial works like OCR for water. You need 1 click per lake.
- natural=coastline is used for ocean coastlines, and perhaps the borders of large lakes (coastline bigger than 1000 points).
- waterway=riverbank - for the banks of large rivers, used in addition to the waterway=river way marking the centre line.
- water=* - a secondary tag for specifying what kind of area of water this is. e.g. water=lake
Key:waterway may list some useful related features.
- waterway=river for narrow rivers
- waterway=riverbank for wider rivers
- natural=coastline for the sea (ocean)
- Proposed_features/Water_cover (eg. intermittent water)
Related terms: <water> <flood> <rain> <wash>