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This proposal replaces an earlier proposal --Swampwallaby 01:46, 14 December 2007 (UTC)


  • Please start discussion for current proposal here.--Swampwallaby 02:17, 14 December 2007 (UTC)
  • Looks good, a yes from me. Thanks for the time spent on the drawings! I've been using man_made=dam but this is equally logical. It would be nice, but not vital, to introduce a convention for which side is "up" and "down" for linear drawing, e.g. down is to the right of the line in the direction of drawing. This convention could then be applied to weirs and cliffs - it is cliffs that I'm really wanting if for. MikeCollinson 08:32, 14 December 2007 (UTC)
  • And another thought, this could also be used for levees perhaps or should they have there own tag? A levee is one of those long embankments along rivers in low lying areas to stop them flooding. MikeCollinson 08:32, 14 December 2007 (UTC)
    • As a none native speaker, I'm a bit confused about the differences to embankment=yes. Could someone clarify this for me? -- Ulfl 09:14, 14 December 2007 (UTC)
  • embankment=yes is a tag added that can theoretically be added to a road to indicate it is raised above the surrounding country. A levee is a stand-alone embankment with no road on top. Mike, I have seen levees drawn on maps as thick black lines, I think that would work well. For the up/down, since we have water on the right for coastlines, it would make sense to have down is to the right. --Swampwallaby 11:04, 14 December 2007 (UTC)
Excellent!! MikeCollinson 15:45, 28 December 2007 (UTC)
  • wouldn't it be cool, to map very big dams as an area? --Cbm 00:13, 29 December 2007 (UTC)


  • Voting commenced 28th December 2007
  • I Approve this proposal. --Swampwallaby 11:23, 28 December 2007 (UTC)
  • I Approve this proposal. --TomChance 11:59, 28 December 2007 (UTC)
  • I approve this proposal. --Eimai 12:26, 28 December 2007 (UTC)
  • I Approve this proposal. -- Franc 13:23, 28 December 2007 (UTC)
  • I Approve this proposal. -- MichaelK 13:25, 28 December 2007 (UTC)
  • I Approve this proposal. --Onion 14:01, 28 December 2007 (UTC)
  • I approve this proposal. Robx 15:13, 28 December 2007 (UTC)
  • I Approve this proposal. -- MikeCollinson 15:46, 28 December 2007 (UTC)
  • I Approve this proposal. -- Myfanwy 03:03, 29 December 2007 (UTC)
  • I Approve this proposal. --Cohort 03:50, 29 December 2007 (UTC)
  • I approve this proposal--Walley 22:08, 29 December 2007 (UTC)
  • I Approve this proposal. -- Ulfl 12:31, 31 December 2007 (UTC)
  • I approve this proposal. --Gummibaerli 23:37, 3 January 2008 (UTC)
  • I approve this proposal. --Cartinus 12:19, 9 January 2008 (UTC)
  • Voting close 11th January 2008
  • Proposal Approved

node for waterway=dam

--acrosscanadatrails 13:47, 17 July 2009 (UTC) in the GeoBaseNHN import, a single node can be presented for those dams which are really small, and the rivers are represented by ways rather than areas. Can I import these, even though they dont yet get rendered?

Beaver Dams?

How would i tag beaver dams? i think they're worth tagging as they last for years and often define a landscape --Dru1138 (talk) 20:43, 18 September 2014 (UTC)

waterway=dam is fine for this purpose, additional tags should (perhaps description) could be used to map additional details. RicoZ (talk) 14:38, 17 October 2014 (UTC)

Constructed dam (infrastructure) should be man_made=dam

Because of ambiguity of the meaning of the word dam, the constructed barrier should rather be in the man_made=* namespace. --Skippern (talk) 16:49, 15 April 2015 (UTC)

Sounds reasonable but with 100k objects mapped this ship has sailed unless a mass-edit is made which is not worth the hassle imho. Also weir and lock_gate have the same problem.--Jojo4u (talk) 17:33, 26 June 2015 (UTC)


When a highway is leading over the dam the object shouldn't mapped with both highway and waterway=dam. Best practise seems to be the dam as an area, highway through that area. When both are ways should dam and highway sharing all nodes or run parallel?--Jojo4u (talk) 17:36, 26 June 2015 (UTC)

The common practice is to have a single way which is indeed tagged with highway and waterway=dam. Even with dam as area people may choose to have an additional waterway=dam for the top of the dam. I consider the original proposal unfortunate in that the area of the dam should be painted with waterway=dam, it would be much cleaner to have waterway=dam for the top of the dam and man_made=dam for the area. Because the area was not rendered at all for many years many people have resorted to waterway=dam+building=something instead which seems semantically cleaner.RicoZ (talk) 10:22, 27 June 2015 (UTC)
Osmose gives a warning with highway+waterway. I think Osmose is right since something is either a dam or a highway not both. What is your reasoning using both man_made=dam and waterway=dam? IMHO a dam with a highway on top should be mapped like bridge, so perhaps highway=*+dam=yes. Double tagging waterway=dam (way and area) is plain wrong/tagging for the renderer, also using building.--Jojo4u (talk) 13:00, 27 June 2015 (UTC)
Ok, I will complain at osmose. dam+highway is correct because it is a single structure, consider it analogous to highway+bridge. Do not try to tag for Keepright or Osmose either. Tagging the walls of a dam with buidling=wall is not tagging for the renderer. RicoZ (talk) 16:46, 27 June 2015 (UTC)
I got confirmation by email from one of the Osmose maintainers - it was caused by an overly generic rule saying that highway=* and waterway=* are incompatible. They are going to fix this one but as usually it may take some time until the fix propagates.
Do you see any other QA tools or validators complaining about this? RicoZ (talk) 10:22, 30 June 2015 (UTC)
Noticed this has also been fixed in the josm validator two years ago . RicoZ (talk) 15:01, 2 July 2015 (UTC)
Nobody tags man_made=bridge+highway=*. There is good reason why it's tagged highway=*+bridge=yes.--Jojo4u (talk) 22:47, 12 July 2015 (UTC)
man_made=bridge is approved and in use, not quite sure what you mean. It is not rendered in mapnik yet and not needed/suitable for all bridges so not everyone uses it. The currently active man_made=bridge is a compromise for backward compatibility reasons, the improved solution when backward compatibility will no longer be an issue would be Proposed_features/Simplify_man_made=bridge_mapping #2.1 and #2.3. RicoZ (talk) 18:11, 14 July 2015 (UTC)


If the dam is drawn as area with waterway=dam should it share nodes with the highway where the highway crosses it? RicoZ (talk) 15:43, 31 May 2016 (UTC)

Replace "wall" by "barrier"

"A wall built across a river or stream to impound the water" seems overly specific, as some dams are Rock-fill or Earth-fill dams. So I would like to suggest using barrier instead of wall. This would also be more inline with the definition on --geow (talk) 20:41, 24 July 2017 (UTC)

Mostly agree. Maybe "A wall or other barrier built...". There other open questions, what is with lakes reservoirs that have a dam all around them? RicoZ (talk) 13:51, 26 July 2017 (UTC)

Dam Emergency Parameters?

We should also have satety parameters attached to the dam. Example Full Reservoir Level, Depth of Water, Capacity, Fill Level, Contact Number. thevikas (talk) 04:34, 29 September 2017 (UTC)

How do we tag different types of dams constructions?

According to Wikipedia there are different types of dams constructions like arch dams, gravity dams, earth wall dams, etc. How would we different constructions for dams? Ivanatora (talk) 16:32, 1 January 2019 (UTC)