In an Australian context, the most common are known as Turkey's Nest dams, because they're mounded up above the ground eg https://c8.alamy.com/comp/A6T7R0/turkey-nest-dam-on-outback-cattle-station-queensland-australia-A6T7R0.jpg
For a full explanation: https://www.agric.wa.gov.au/water-management/excavated-tanks-farm-dams Thanks Graeme On Thu, 17 Dec 2020 at 11:53, Joseph Guillaume <josephguilla...@gmail.com> wrote: > That Wikipedia page is right. > The artificial grading mostly involves creating an (earthen) dam wall > (which is often also mapped), and the purpose is generally retention of > water rather than infiltration or detention, which is why the distinction > between reservoir and basin isn't clear cut to me. > > I'm having trouble thinking of it as a basin, but it does seem like this > is the intended tag. Thanks! > > > > On Thu, 17 Dec 2020, 12:29 pm Joseph Eisenberg, < > joseph.eisenb...@gmail.com> wrote: > >> What is a farm dam in this context? We don't have that term in American >> English. >> >> Is this perhaps an example of landuse=basin (or if you prefer >> water=basin) with basin=detention or basin=infiltration? >> >> https://wiki.openstreetmap.org/wiki/Tag:landuse%3Dbasin >> >> https://en.wikipedia.org/wiki/Dam_(agricultural_reservoir) >> >> -- Joseph Eisenberg >> >> On Wed, Dec 16, 2020 at 1:29 PM Joseph Guillaume < >> josephguilla...@gmail.com> wrote: >> >>> This discussion has convinced me not to use landuse=reservoir. >>> >>> It sounds like the only benefit is its historical use, whereas I've >>> personally seen benefits of the natural=water approach. >>> >>> I've mapped quite a number of farm dams as natural=water without being >>> sure what subtag to use. >>> I now think that's because there isn't an appropriate subtag. I >>> definitely don't want to tag it as a pond. While a farm dam is structurally >>> and functionally a reservoir, there are clear differences with large >>> reservoirs. >>> >>> Already now, farm dams tend to be mapped more prominently than I'd >>> expect. The dominant feature of these grazing landscapes is fencing, and >>> I'd therefore expect farm dams to appear on a similar scale to fences. >>> water=reservoir and landuse=reservoir wouldn't do that. >>> >>> One of the things I love about OSM is the ability to map incrementally, >>> which by definition results in incomplete, lower quality maps that are >>> constantly improving. If the priority was a high quality map, we'd map >>> systematically (like Missing maps, but for everything that will appear on a >>> render) and not release an area until it was done. I wouldn't be mapping. >>> >>> >>> On Thu, 17 Dec 2020, 1:26 am Tomas Straupis, <tomasstrau...@gmail.com> >>> wrote: >>> >>>> 2020-12-16, tr, 16:01 Mateusz Konieczny rašė: >>>> > >>>> https://wiki.openstreetmap.org/wiki/Tag:landuse%3Dreservoir#water.3Dreservoir >>>> > (just added) >>>> >>>> Thank you. Maybe it is better to discuss here before adding to wiki? >>>> My arguments on the points you've added: >>>> >>>> 1. Regarding benefit of having a combining level/tag natural=water. >>>> If today you would query all data with natural=water - you will get >>>> not only lakes and reservoirs grouped, but also riverbank polygons >>>> (totally different beast) and micro elements like water=pond. This >>>> could only be partly useful in the largest scale maps and only if you >>>> make very simple maps and for some reason use the same symbolisation >>>> for such different water classes. For example ponds usually have less >>>> complex and less prominent symbolisation because of their size and >>>> importance. Riverbanks would not need polygon labelling, but rather >>>> use river (central) line for label placement. Most of GIS/Cartography >>>> work goes in middle/small scales and it will be impossible to use only >>>> natural=water there, you would have to add "and water not in >>>> ('riverbank', 'pond', ...)". This erodes the benefit of "one tag" and >>>> makes it of the same complexity from coding perspective as original >>>> water scheme. >>>> >>>> 2. Very important disadvantage of water=reservoir from >>>> cartographic/gis perspective: it allows mappers to NOT differentiate >>>> between natural lakes and man made reservoirs. If first point >>>> describes how different classes are USED, this second point is about >>>> how these classes are CAPTURED. >>>> >>>> Did I miss anything? >>>> >>>> _______________________________________________ >>>> Tagging mailing list >>>> Tagging@openstreetmap.org >>>> https://lists.openstreetmap.org/listinfo/tagging >>>> >>> _______________________________________________ >>> Tagging mailing list >>> Tagging@openstreetmap.org >>> https://lists.openstreetmap.org/listinfo/tagging >>> >> _______________________________________________ >> Tagging mailing list >> Tagging@openstreetmap.org >> https://lists.openstreetmap.org/listinfo/tagging >> > _______________________________________________ > Tagging mailing list > Tagging@openstreetmap.org > https://lists.openstreetmap.org/listinfo/tagging >
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