Doubt tagging river Ulla

Hello everybody! This is my first post in the forum, though I’ve been mappin for more than a year now.

I have a doubt. I’ve been mapping near Padron (Galicia, Spain) and I’ve found that river Ulla is tagged as a multipolygon and its only tag is “source=PGS”.I googled what this was. Apparently it is rendered (at last in Potlatch) like a properly tagged river. My doubt is: is it worth the effort to change the tagging to “waterway=river” and "waterway=“riverbank”? Is it even necesary?

I have experimentally tagged two branches as can be seen in Should I go on with the entire river?

I’m not sure what you encountered and what you’ve changed.
At the coordinates you posted I see a way, which is the river itself, a second way, which is a sidearm of the river, two ways (1, 2), which are the area of the sidearm (both created by you), and a basicly untagged way, which is the outer of a multipolygon, which is the area of the river.

I guess you mean a difference between the branches and the main river, but I don’t see any (besides the multipolygon which imo could be a normal polygon).

Supplemental: I can’t find a waterway=river for the rest of the river. If that’s what you meant: Yes, that should get fixed.

Hello Polkillas,

if you want to have an overview how waterways (or even other OSM map objects) are tagged in your area, have a look at the OSM-Inspector provided by

Go to and choose the view “Water” there … and zoom in to your area. Are there any differences how waterways are tagged in spain?

similar views are available via

The “waterway=riverbank” tag is on the multipolygon relation:

You don’t have to put the tag on the way itself if it is already on the relation.