On the northern side, from the mouth upwards only beyond Betzenberg only short tributaries compete with the Aich which takes the Schaich, in the area of the upper course then its partly very near tributary Seitenbach which also runs about east. Finally, north of the immediate source area of the Schaich, only about one kilometre away, the Altdorfer Würm, a branch of the Würm, which drains via the Nagold and the Enz only much further down than the Aich into the Neckar. The watershed, which is less prominent on this section than towards the south, is therefore hydrologically the most important.