Oops - what did I break? (feature disappears, how to revert changes)

General talk
1

I wanted to correct/refine a dam outline to more accurately represent the normal waterlevel, I did this using the web ‘Edit’ feature, resulting in the following changesets:
https://www.openstreetmap.org/changeset/42124717
https://www.openstreetmap.org/changeset/42125237

Alas, I presume as a result of my edit, the entire dam seems to have disappeared:
http://www.openstreetmap.org/#map=17/-33.48236/150.24957&layers=C

I’ve no firm idea what I did to cause this (I suspect disconnecting the little “island” that was the focus of the edit?), nor can I figure out how to revert it. Following the http://wiki.openstreetmap.org/wiki/Change_rollback notes, I opened the area in Potlach:
http://www.openstreetmap.org/edit?editor=potlatch#map=17/-33.48225/150.24919

But the dam seems a-ok there.

Could someone advise on:

  1. what happened to make the dam disappear
  2. how I can revert my changes, or fix whatever’s broken

Thanks!
Ben

2

The tagging is not conventional. the area should be tagged either with landuse=reservoir or natural=water. The waterway=dam tag should be used solely for the actual dam keeping the water there.

I’ve put both tags on the water & added a waterway=dam based on the aerial imagery.

In addition I’ve tweaked it so the wood icons shouldnt appear over the water.

3

Hi Ben
you have linked to the Cycle Map layer of the Openstreetmap, but I don’t think that displays dams, but it does display water bodies. The water body behind the dam wall displays fine on the Standard layer of the map, though see below.

A couple of points…

Whilst it is common to call these water bodies dams in Australia, when editing the openstreetmap the outline of the water body should be tagged natural=water plus water=reservoir and in this case probably name=Dargan’s Dam

The part that is tagged waterway=dam is normally the construction that has been built to hold back the water. In this case it appears to be a curved wall at the southern end of the water body. Due to it’s large size, the Hinze Dam in southeast Qld http://www.openstreetmap.org/#map=16/-28.0505/153.2925 has the surrounding earth mount and the wall area tagged as the dam, but in your dam it appears to be just the wall that holds back the water.

The wiki has some help on this here http://wiki.openstreetmap.org/wiki/Tag:waterway%3Ddam

Edit: Ooops, SK53 has answered whilst I was typing.

4

Incidentally, I noticed that the Bing imagery was used, but there is also more recent and higher resolution LPI NSW imagery available (at least in JOSM)

5

Righto; I didn’t change the tags (I think), just the boundary, though understood re. waterways vs. dams, and thanks SK53 for fixing it.

Thanks nevw for the point re. cycle map layer - I didn’t realise I’d switched!