Working around 2000 node limit?

I started adding detail to a very large lake that was put it roughly, and I hit the 2000 node limit. How should I work around it, considering that I want to keep the rough lake outline while I update it?


Make smaler pieces like here or like here

lake != riverbank

@deadrabbit: You can cut the lake shore up into shorter sections, and then collect them into a multipolygon relation as outer ways.

Make a new relation, set the tags up as type=multipolygon, and add those shore line sections as members with their role set as ‘outer’.

That’s why I wrote “like” and not “as”. It was meant as an example of how to draw bigger areas with multiple chunks.


Great, thanks!

Hi guys, new user. I am using JOSM to do my editing. I have downloaded a fairly large local area to edit and although I didn’t really add any nodes (a few) it says that I’m 400’ish over the limit. I also used the SimplifyWay plugin to cut down on the number of nodes. Obviously it won’t let me upload my changes. I see the original poster had the same problem. My problem is, I don’t understand what you have suggested they try. I have a huge lake that’s 2,265 nodes. How do I split it up for uploading. I read the supplied links, still don’t understand. “You can cut the lake shore up into shorter sections, and then collect them into a multipolygon relation as outer ways.” How do you do this? How would you then upload the different sections? I’m confused, any help would be appreciated.

Also something I don’t understand. I didn’t make any changes to the lake, just the surrounding roads. Excuse my lack of knowledge, but could I create 2 osm files, delete the lake from one, and then the roads from the other, and upload as 2 separate files, if you understand what I mean, or would OSM go from having lake and roads to having just lake and then just roads for that area.

Thanks Glen

First off, don’t split it up in 2 .osm files, unless you (or us) want to deal with a major head ache. :slight_smile:

  • If you have a circular way of 2265 nodes (your lake), you can select 2 nodes on opposite ends, and split the way (‘P’ in JOSM). Doesn’t matter which nodes, as long as you end up with 2 sections that are each shorter than 2000 nodes. JOSM will probably no longer paint the lake in a blue tint after you did this.
  • Due to a peculiarity in the way JOSM works (or the API, opinions differ), you now have to upload your change to the OSM database.
  • After the upload is done, select those 2 ways.
  • Create a new relation, add those 2 selected ways to the relation and set their role as ‘outer’ (without the quotes, obviously).
  • Then at the top of the relation editor, add the tag: type=multipolygon. (‘type’ in the left field, ‘multipolygon’ in the right), and exit the relation editor with OK.
  • If you did that right, JOSM will also recognize the whole lake again, and paint it blue.
  • Upload again.


Take a look at Lake Oahe:

Split the way (lake) in 2 (or more) pieces by selecting 2 nodes and hit “p” for sPlit. Draw a way from one shore to the other and "C"ombine the ways to get a closed way of water. Do the same with the other half of the initial way. I add some overlapping where I cut the lake into pieces. Don’t know if this is still needed but that’s the way I learned and see it.

Hi, thanks for the quick response.

I actually figured it out, but have an error screen coming up when I upload. I don’t know how to post a screen shot here but the error is a warning:

Data with errors, upload anyway?
natural type water = Unclosed way (2)
1267 nodes
1000 nodes

What next?


edit :It shows fine in JOSM, 2 halves, all blue.

Fix it! :slight_smile:

If you split the lake you have to endup with 2 (or more) lakes overlapping each other where you split the original lake.

Yoou have one closed Way (way1)
Split way1 at node A and B. The result will be way2 and way3.
Draw a new way from node A to B (this will be way4). To avoild complains from JOSM about overlapping ways / areas you might want to add an additional node (C) between node A and B.
Now combine way2 with way4 to get a new closed way (representing the first half of the lake)
Now draw an other way between node B and A (straight, no additional node needed). This is way5.
Combine way5 with way3 te get the second half of your lake.

JOSM will fill a way natural=water blue regardsless if this way is closed or not. Normaly JOSM should indicate WHERE the way is unclosed by highlighting the unconnected nodes…

Ok, split the lake in two, new upload error.

Thanks for any help


This is because you deleted the node 387358052 from way Camel Lak Road (33867784). But this node is also part of way Stephenson 2 Road W (33862172), where this node is still valid. I guess this node was outside your downloaded area, so could delete him without updating “Stephenson 2 Road W”.

How to solve this problem? I don’t know. Reverting all changes in your OSM until you reach the point where you deleted the node doesn’t seem to be an option. I remember there was an easyer way by open the OSM-File with a text editor, search for ‘id=387358052’ and then change something to something else… :roll_eyes: Try the search-function of this forum or the mailing-lists.

@PHerison: Your advice about splitting, joining through the middle, and using an overlap, probably predates relations. Besides, an overlap is not needed.

@Muskoka: JOSM warns you because the two natural=water ways are indeed not-closed. You can ignore that, because the relation sorts it out, actually. You could also take the natural=water off the ways, and add it to the relation. Or do both, leave it on the ways, and set it on the relation as well (but JOSM will still complain about the ways). When it gets to the renderers, they will take the relation and its members, and recreate the entire lake as an object to draw.

Hi guys, thanks for all the help.

I have split the lake in two, when I try to upload I get this error. I did try both your methods and get the same error. Can’t find this “way”, don’t understand the error, or what it wants me to do.

Thanks Glen

Somebody edited a node that is also used by your lake. You need to update your data before you try to upload again.

Thanks again for all the help. Upload completed, everything appears to be ok.