Pau (also: Paubach) is a small river of Aachen, North Rhine-Westphalia, Germany.

It it is 4.1 km long and flows into the Wurm as a left tributary.

[1] The Johannisbach is one of the three historic streams of the medieval city of Aachen.

The Johannisbach was used for the disposal of wastewater, while the Pau was diverted to serve as the source of fresh water.

This article related to a river in North Rhine-Westphalia is a stub.