Hi Janjko, thanks for the comment. I think waterway=dam is not correct, because for this lake, the dam is not built *across* the water, but rather around it. From https://wiki.openstreetmap.org/wiki/Tag:waterway=dam: "A barrier built across a river or stream to impound the water". So this is why I tagged this as man_made=embankment, because there is also a road on the embankment in some places. Another option would be man_made=dyke or embankment=dyke.