[Tagging] Feature Proposal - RFC - Check dam

[Yves]

I'll add 'siphon' to the list "fin", "rake", "beam" and "frame" to say that they represent a particular hazard.
I recognize that the french bare translation of weir is 'seuil', so I have the mental image of the usual step-like weir. This seems restrictive compared to the Wikipedia definition 
Given previously.
Regards,
Yves 

Le 8 juin 2021 07:32:11 GMT+02:00, Joseph Eisenberg <joseph.eisenberg at gmail.com> a écrit :
>Looking at the examples, I think the solid check dams where water is
>designed to flow over the top can be mapped with the current waterway=weir
>tag.
>
>The slot and slit dams might be categorized as a sub-type of waterway=dam
>since they are mostly solid but allow a small amount of water to pass
>through the dam. Many standard dams have gates, spillways or other channels
>for a small amount of water to pass through the structure.
>
>However, I agree that the "fin", "rake", "beam" and "frame" structures are
>not at all like a waterway=dam or =weir, since they are not solid
>structures and do not normally impede passage of water, rather they are
>designed to catch debris, rocks and logs which might otherwise be swept
>downstream during flooding.
>
>
>On Mon, Jun 7, 2021 at 2:30 PM Enno Hermann <enno.hermann at gmail.com> wrote:
>
>> <https://goo.gl/maps/PrtuW627ndkc3NbX7>
>>
>> On Mon, Jun 7, 2021 at 6:03 PM Mateusz Konieczny via Tagging <
>> tagging at openstreetmap.org> wrote:
>>
>>>
>>> https://wiki.openstreetmap.org/wiki/File:Check_dam_on_Miya_River_(Jinzu_River).jpg
>>> for me it looks like waterway=weir
>>>
>>> "Solid check dams usually have water flowing over only a small part of
>>> their width and
>>> are designed to handle sudden increases in water flow."
>>>
>>> Are you sure that thing depicted on image is not also a weir?
>>>
>>
>> I agree that it's not the best example and from this picture alone it
>> could be hard to tell, although the construction is typical for check dams.
>> I managed to find the location and on Google Streetview (
>> https://goo.gl/maps/PrtuW627ndkc3NbX7) or the Japan GSI seamlessphoto
>> imagery (https://osm.org/go/7QeF1CmI6) the water level is clearly
>> different and water seems to be flowing only through the bottom of the
>> structure. Given that, the mountainous terrain and similar structures
>> nearby I would say it is clearly a check dam.
>>
>>
>>> And "designed to handle sudden increases in water flow." is applicable to
>>> any sanely constructed waterway engineering.
>>>
>>
>> "sudden and significant" might fit better. Often those streams are
>> normally only a trickle or even completely dry but then can see sudden
>> debris flows like this: https://www.youtube.com/watch?v=2Rfuoylv34k This
>> is different from floods on already larger rivers.
>>
>>
>>> See
>>> https://en.wikipedia.org/wiki/File:Culverts_under_yass_river_walkway_weir.JPG
>>> on Wikipedia weir page.
>>>
>>> Or https://en.wikipedia.org/wiki/File:Grial%C3%ABces_cuecenes.jpg with
>>> description
>>> "During periods of high river flow, this nineteenth century weir of
>>> porphyry stone on
>>> a creek in the Alps would have significantly more water flowing over it."
>>>
>>
>> An early example of a check dam? ;) I'd say very small structures or
>> simple constructions that can't be clearly identified as a check dam may
>> just be tagged as weirs.
>> _______________________________________________
>> Tagging mailing list
>> Tagging at openstreetmap.org
>> https://lists.openstreetmap.org/listinfo/tagging
>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/tagging/attachments/20210608/21138df5/attachment.htm>