After one and a half kilometres it turns north and from its confluence with the Nordbach, which joins it from the west at Schwenningdorf, is known as the Große Aue.

On the western edge of Espelkamp (65 kilometres) in the river meadows on the far side of the dyke, two small lakes have been laid out: the Großer Auesee and the See am Kleihügel.

It flows eastwards through the southern part of the Sulingen Gap and is then forced south by the geest hills of the Steyerberg Forest.

The artificial water channel was largely retained, but parallel to it a new river course was laid out which ran along the old route in several places.

Threatened dragonflies, such as the banded darter, southern emerald damselfly live here as do birds like the whitethroat and little grebe.

The near-natural grassland and wet meadows in the upper reaches of the river near Rödinghausen are under nature conservation protection.