Switzerland:Bisses
 historic = bisse
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| Used on these elements |
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| Status: proposed |
| Tools for this tag |
This page proposes how to map the bisses (French) or Suonen (German) of Valais, Switzerland: historic open-flow irrigation channels, that carry water from alpine streams and glaciers to vineyards and meadows on drier slopes. They may still be in active use for irrigation or survive only as disused channels, and many sections have been converted into hiking trails running alongside the water.
How to map
Main waterway tag
Map the water channel itself as a way 
and tag it:
name=*
- Name of the bisse.
- A bisse is a man-made, open-flow channel.
waterway=drainandwaterway=ditchare not appropriate because those are for drainage channels, whereas a bisse supplies useful water for irrigation.
- Distinguishes the bisse from canals used for transport or hydropower.
intermittent=yes and seasonal=yes or seasonal=summer
- Most bisses only carry water in summer and water flow may still vary regularly.
- Allows to uniquely identify a canal as a bisse.
wikidata=*
- Wikidata item of the bisse.
- Wikimedia Commons category for the bisse (or image of an individual section).
For simplicity, avoid waterway relations where possible.
Useful tags for individual sections
Bisses are built in a variety of ways depending on terrain — carved into rock, running through wooden or metal flumes bolted to a cliff face, buried, or lined with concrete. Where relevant and verifiable, tag:
| Tag | Picture | Description |
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disused:waterway=canal
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Where a section no longer carries water but the channel/structure is still
visible (verify this in summer when the bisse would usually carry water). |
abandoned:waterway=canal
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Sections where the main channel has been removed, but other obvious traces remain. |
material=ground
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Basic channel in the ground. |
material=wood
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Wooden channel. Often elevated, so bridge=aqueduct is also appropriate.
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material=metal
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Metal channel. |
material=stone
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Stone channel. |
material=concrete
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.jpg)
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Concrete-lined channel. |
tunnel=culvert
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For underground sections. inlet=screen or inlet=direct may be used at the tunnel entrances where appropriate.
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width=*
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Width of the bisse section. |
Additional features
| Tag | Picture | Description |
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waterway=sluice_gate
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Node  on the waterway. Commonly found at the start to regulate overall water flow and along the bisse to divert water to other areas.
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man_made=watermill, watermill=acoustic_signal
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Node on the waterway. Small watermills found along some bisses. They generate acoustic signals at a regular interval that allows to verify water flow.
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hazard=falling_rocks
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Path sections along a bisse where signs warn of rockfall.
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Parallel hiking paths
Many bisses have a highway=path running directly alongside them. Map the path and the canal as separate ways even where they run parallel for long stretches. Only set the name of the bisse on the waterway, not on the path. Use a relation if there is a signed hiking route, see Switzerland/HikingNetwork for more details.
Example
The Bisse de Trient is micro-mapped in detail, e.g. 1536026358 1536026358.