@VDL549: Many rivers in OSM have an article prefix.  Die means "The".

Incidently, the wikipedia article is named "Warche" because all wikipedia articles use the canonical form, but the text starts with "Die Warche".
https://de.wikipedia.org/wiki/Warche

Take a loot ak this one: name is "La Meuse" despite the Wikipedia article will use the short version, i.e. "Meuse".
https://www.openstreetmap.org/relation/1075197

"name=La Seine" in Paris, same situation.
https://www.openstreetmap.org/way/677465328

There is nothing wrong about this, this is just a convention.