How do you tag a gully left by what, according to the topo maps, up until a few years ago used to be a creek?

The official name of the feature is Hicks Canyon Wash. It is tree-lined, has a few foot bridges, is impassable to vehicular traffic and serves as a natural boundary of an area of the city. In other words, it's a pretty significant local feature, but to tag it a stream would be a misnomer.

I know there is an intermittent=yes tag and I have, indeed, seen puddles at the bottom of the gully after major storms, but I'm not sure if renderers or anyone else would pay attention. Right now, it shows as a blue line on Mapnik map (tagged waterway=stream, intermittent=yes), but on Google Map, if that's any kind of reference, it's missing, while other streams in the area are shown - even tiny ones, as long as they are "wet".

I tend to agree with Google that it should not be blue, and I also know that we don't tag for the renderer. So, what's the answer? I guess I could just delete it, but I was planning on using it in a boundary relation, because that would be a pretty accurate representation of the physical world, and that's what OSM is all about. Right?

asked 12 Apr '11, 21:57

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ponzu
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edited 22 Mar '13, 11:17

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sleske
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in such a case I strick with "intermittent=yes"...

(13 Apr '11, 10:13) Herve5

When you know that we don't tag for the renderer you should also know we don't delete for the renderer. :)

For using the waterway as a / in a boundary: I would discourage this but recommend to use an extra way only for the relation.

(06 Feb '14, 21:04) malenki

I think tagged waterway=stream, intermittent=yes is actually appropriate here.

To address your qualms about using these tags:

In other words, it's a pretty significant local feature, but to tag it a stream would be a misnomer.

You are not tagging it as just a stream, but as an intermittent stream, which is different.

I know there is an intermittent=yes tag [...] but I'm not sure if renderers or anyone else would pay attention.

As you correctly point out, that's not your problem, as you are not supposed to tag for the renderer. Actually, I believe at least Mapnik now supports intermittent=yes.

At any rate, the distinction between "intermittent stream" and "permanently dry" is somewhat arbitrary - even regular streets can become streams if there is enough rain :-). So I don't see a problem with using intermittent=yes even if the stream bed is almost always dry.

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answered 13 Apr '11, 12:39

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edited 13 Apr '11, 12:39

I like your answer. I don't think Mapnik made my intermittent=yes stream any less blue than a normal stream, but that's a problem (if that's a problem), that probably should be addressed.

I wonder if your answer would be any different if I had asked how to tag a gully. I did not even know what a gully was until I looked up "ravine" and found that it's smaller than a canyon and bigger than a gully. Then I looked up "gully" and from description and pictures knew that that's exactly what Hicks Canyon Wash has become. Are we maybe looking at a new natural tag? It's got fell, scree, heath, etc.

(13 Apr '11, 19:00) ponzu

According to the wiki, intermittent streams are rendered with a dotted/dashed blue line, and that's how other maps normally show them. I haven't been able to find any intermittent streams yet, so can't confirm that. Maybe try it and see.

(13 Apr '11, 19:36) tongro

Here it is: http://www.openstreetmap.org/?lat=33.72226&lon=-117.76505&zoom=17&layers=M Not dotted or dashed. I think I might open a Trac ticket.

(13 Apr '11, 19:44) ponzu
2

@ponzu: Update: I just checked, the stream linked in the previous comment is now rendered dotted. Seems to work now.

(23 May '12, 10:44) sleske
1

@sleske actually it's not, that dotting is because of an overlapping boundary line, and at west because of a tunnel. Follow to the east and... it's not working :(

(05 Feb '14, 19:04) bigstones

There are several intermittent streams in areas I've mapped and the default renderer at http://www.openstreetmap.org ignores the intermittent tag. Makes the map look much wetter in than it really is. The rendering I setup for generating some maps in those same areas use the USGS typical dashed, dotted format, so I know its possible to get Mapnik to do it.

(05 Feb '14, 21:19) stf

@stf: Yes, I was mistaken, the standard OSM map still ignores the intermittent tag. However, recently a bug was opened to get this fixed: https://github.com/gravitystorm/openstreetmap-carto/issues/805 So there is hope :-).

(15 Oct '14, 11:46) sleske
showing 5 of 7 show 2 more comments

An alternative tag for creeks, washes, arroyos etc, is waterway=wadi http://wiki.openstreetmap.org/wiki/Tag:waterway%3Dwadi

Currently this is rendered correctly in Mapnik as a dotted blue line, though it doesn't display any naming. Unfortunately some renderers don't seem to recognize this tag at all - e.g. Mapquest, which won't display waterways tagged this way.

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answered 18 Jan '15, 00:40

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And there is some discussion about waterway=wadi on the tagging mail list under the title of "waterway=wadi problem". I think there is a possibility that waterway=wadi might become deprecated.

(18 Jan '15, 04:12) stf
1

I have been having the same dilema recently until I found waterway=wadi and natural=gully to complement waterway=stream in combination with intermittent=yes. I don't think the maps render a gully yet. (I can't check now)

(21 Jan '15, 11:19) nevw

I actually go the other way, tagging ephemeral riverbeds with waterway=stream/river, intermittent=yes, seasonal=no - I'm not sure what waterway=wadi adds to this. It's annoying to see Mapnik display areas of desert as if they are covered in rivers, but that's a rendering problem - the Humanitarian layer does a better job with intermittent=yes waterways, presumably because of the areas of the globe they're interested in. The help pages are probably not a good place for a debate - I would recommend the tagging mailing list mentioned by user stf above, under the title "waterway=wadi problem"

(22 Jan '15, 00:09) tomthepom

I would go with waterway=wadi because it is dry most of the time and only flowing with heavy rains. There is a note with this that states that it is also known as a wash in the deserts of America. At present adding intermittent=yes does not change the line on the map and it still shows as a solid line. waterway=wadi does give a pecked line indicating that it does not have flowing water all the time. I am attempting to get this changed to waterway=river-perennial / stream-perennial which has water all year round and is depicted by a solid blue line, next is waterway=river-nonperennial / stream-nonperennial which has water some of the year and is depicted with a pecked blue line, lastly is waterway=wadi which may only occasionally have water in very heavy rains and depicted with a brown pecked line. This may not happen but I am trying.

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answered 20 Jan '15, 23:18

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edited 21 Jan '15, 21:04

As an addendum to this topic, the standard (Mapnik) map now renders waterway=river/stream, intermittent=yes as a dashed blue lines, with waterway=river rendering as a thicker line than waterway=stream.

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answered 09 Feb '15, 13:54

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While there has been talk of deprecating the tag Waterway=wadi I am against this. The word wadi is putting people off using this tag and maybe the wording should be changed to waterway=dry_river which would then be far more acceptable to more people. Intermittent is usually accepted as being a stream but can be dry during some parts of the year. A wadi is dry most of the time, even years before a sufficiently heavy downpour will turn it into a flowing waterway that will dry up again when the rains stop and is therefore more of a feature than a waterway. Which is what is described by @ponzu. I would still go with waterway=wadi which I would recommend being a pecked brown line rather than blue, but we are restricted to what is available at the present. If there is sufficient use of the tag waterway=wadi then there will be sufficient case for renaming and/or rendering it differently. The present opposition to the brown pecked line is the clash with highway=track. The discussion regarding rendering is here https://github.com/gravitystorm/openstreetmap-carto/issues/805 and https://github.com/gravitystorm/openstreetmap-carto/issues/1255#issuecomment-71403860

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answered 09 Feb '15, 15:07

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edited 09 Feb '15, 15:20

I think one issue with "wadi" is that is also means the entire valley that said dry waterway may be in.

(09 Feb '15, 18:21) stf

This type of issue crops up in a number of discussions. There is no way that we are going to find a single word in our language that will satisfy all languages throughout the world. Even in the Arabic languages the meaning of wadi can range from a flowing river to a dry valley depending on where you are. In the Maghreb wadi applies to all rivers. https://en.wikipedia.org/wiki/Wadi

(11 Feb '15, 01:10) RAytoun

I tend to agree and feel we need a more generic tag such as something like waterway=dry_watercourse The wadi would be one of the many variations that could fit under such a category.

(11 Feb '15, 05:47) nevw
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question asked: 12 Apr '11, 21:57

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