Hi,
The upper section was promoted about 2 years ago from stream to river:
https://www.openstreetmap.org/way/810215545/history

After walking many times along this section, it's hardly a raging torrent, but by the OSM definition, even when in a deep concrete channel, it's a river (and previously marked width=4):
https://wiki.openstreetmap.org/wiki/Tag:waterway=river

https://www.openstreetmap.org/changeset/133716605

Happy Mapping,
James