"waterway=canal" + "tunnel=yes" is valid !

[verdyp@…]

A canal may be under a tunnel (here at layer -1, below a large railway on the ground level without embankment), like other waterways. See the attached screenshot.

A canal may also be built to pass over a bridge (various examples in France, like Canal du Midi, or elsewhere).

Why does JOSM signal it as "suspect" ? What would be suspect and would need to be signaled is only if a canal cross another highway or waterway or railway, at the same layer (the implied layer is 0 if not specified), and without any intersection node appropriately tagged for their crossing (But this is not the case here).

[verdyp@…]

a valid canal in a tunnel below a railway

[Don-vip]

Rule comes from r13972 / #16147

[francois.lacombe]

Example from Verdyp should be tagged tunnel=culvert

Tunnel=yes means the tunnel is safely accessible by human in operation
​https://wiki.openstreetmap.org/wiki/File:Waterway_pipeline_in_tunnel.png

[verdyp@…]

There are various examples of canals inside tunnels, notably in dense cities (e.g. the Canal Saint-Martin, in Paris, France, has several tunnelled sections). This also occurs for rivers (e.g. the Vilaine in Rennes, France).

[anonymous]

The "culvert" is not applicable everywhere if there are no "busards"; culverts are too narrow and have too low depth, and so are normally not navigatable, this would remain a canal.

The Canal Saint-Martin in Paris is really navigatable

[francois.lacombe]

Indeed Canal Saint Martin is a good example and it could possibly considered safe to access it in operation
​https://www.1843magazine.com/content/places/going-souterrain

It's not the case of almost canals going through railways or roads, the water fills the whole section of the culvert.

A good option could be to ask for access=* on waterway=* + tunnel=yes to force users to think about how the structure can be accessed (and sometime discover human can't go inside - so validation error for waterway=* + tunnel=yes + access=no)
Goog value for Canal Saint Martin could be waterway=canal + tunnel=yes + access=private

[anonymous]

The Canal Saint-Martin in Paris is used by any boat (notably "péniches", with heavy loads, and excursion boats), it is definitely not "private" (it is regulated like other canals).

There are even public pathways below the built surface along the canal...

[francois.lacombe]

Public pathways, oh really ? :)

Then access=yes, no problem

I just don't want this to be described with tunnel=yes
​https://wiki.openstreetmap.org/wiki/File:Waterway_drain_outlet.jpg

[skyper]

Have a look at Madeira.

• waterway on bridge: ​osmwww:way/698103141
• waterway within tunnel: ​osmwww:way/698132267
  • should be tagged without tunnel=* and not even with covered=* as the levada runs uncovered through the tunnel
• waterway + highway in tunnel: ​osmwww:way/266000222
  • should be separated.

[francois.lacombe]

Thank you for examples

No problem with the bridge

If Levada actually runs in tunnels, it should be described with tunnel=flooded or tunnel=culvert as I understand the configuration in place
Do you eventually have pictures please?

[skyper]

open waterway in tunnel and covered before

[skyper]

tunnel with open waterway

[Hb---]

Replying to verdyp@…:

See the attached screenshot.

With JOSM r15958 I do not get any warning for ​osmwww:way/227778561. Please provide a situation that fits to the current release.

[skyper]

waterway on bridge

[francois.lacombe]

Ok @skyper this is definitely waterway=canal + tunnel=yes + access=yes

[verdyp@…]

Note that given your advice, I have changed it AFTER myu initial comment to tunnel=culvert (this is not the same case as canal Saint-Martin in Paris where this is definitely not a culvert as there are pathways inside the tunnel on the same level as outdoor sections of the same canal).

I got the warning when it was tunnel=yes.

Waterway running along bridges also exist. They should all be canals, even if they were built to canalize the waters of a natural river, whose course was changed to avoid falling down; there may be examples where the bridge was built along the natural course while at the same time digging a large area below it, possibly to connect urbanized areas or to extend a lake created by a dam elsewhere or to extend an harbour, but did not find any example; one reason would be to preserve the natural flow of the river passing over this enlarged area).

[Klumbumbus]

Replying to Hb---:

With JOSM r15958 I do not get any warning for ​osmwww:way/227778561.

Because the screenshot uses tunnel=yes and the current osm object tunnel=culvert.

[verdyp@…]

For an example of a river in a tunnel, see ​https://www.openstreetmap.org/way/70292145
(Actually the river is canalized, but boats can go under it, even leasure boats).

Above this tunnel there's a parkings, trees, and a large pedestrian area...
But there's no pathway below the tunnel which is entirely and permanently flooded; navigation is not restricted (except by maxheight); the level of waters is controled by lock gates along the river (upstream and downstream) and its canalized tributary (L'Ille).

The tunnel was built by covering the river in the 1960's.

@Hb--: Note that my snapshot was accurate for the situation, and clearly showed the situation when it was tunnel=yes (as seen in the snapshot itself, with "tunnel=yes" tag highlighted in yellow)... so your comment was junk.

[anonymous]

Also I changed tunnel=covered, but gave a warning: there's no restriction boat=no, so I'm not sure that boats cannot go below it. If they can (there's enough depth, and the tunnel is not fully under water because the level of waters in the canal is controled by locks), then this is definitely not a "culvert".

[anonymous]

Here is an example of a canal over a bridge (also subtagged as an "bridge=aqueduct")

​https://www.openstreetmap.org/way/97458482

The canal-bridge was built to avoid flooding the small river under it that it passes through.

Another similar example on the same canal:

​https://www.openstreetmap.org/way/61744550#map=19/43.23771/2.37322

(there's also a parallel bridge for a road)

Also:

​https://www.openstreetmap.org/way/97382615

(it passes over a small stream)

Same case:

​https://www.openstreetmap.org/way/200927913

Over a larger river:

​https://www.openstreetmap.org/way/30498554

etc...

[mdk]

Weiter Beispiele:
Mittlere-Isar-Kanal Tunnel bei Appolding:
​https://commons.wikimedia.org/wiki/File:Mittlere-Isar-Kanal,_Tunnel_Appolding,_03.jpeg

Rhein-Marne-Kanal-Tunnel
​https://de.wikipedia.org/wiki/Datei:Rhein-Marne-Kanal-Tunnel_01.JPG

Kanaltunnel des Huddersfield-Narrow-Kanals
​https://de.wikipedia.org/wiki/Datei:Tunnel_Entrance_Gates_at_Diggle_-_geograph.org.uk_-_251745.jpg

Oder hier:
​http://www.beluga-on-tour.de/html/Kinderecke-Caro/Tunnel.htm

[Klumbumbus]

In 17790/josm:

fix #18815, see #16147 - Don't warn about waterway=canal together with tunnel=yes and don't warn about bridge/tunnel=* on type=bridge/tunnel relations