[2] Starzel is being built directly at Albtrauf at the European watershed, about three kilometres south of Hausen im Killertal.

After the passage of Rangendingen it turns to the north and finally flows into Bieringen at a height of 354 m above sea level, from the right into the Neckar.

It begins with the source area of the Starzel and its tributaries at the watershed between the river system of the Rhine and that of the Danube.

A special feature are the so-called waterfall layers, a hard sandstone, which is bedded over leafy shale clays.

In the evening of 2 June 2008, a thunderstorm caused heavy rainfall and flooding, as a result of which three women drowned, two in Jungingen and one in Hechingen.