About 100 metres into the Hachinger Tal, the ground becomes progressively wetter due to exudation of groundwater, until a small stream forms.

Like almost all waterways in Germany, the Hachinger Bach was regulated in the past, and had its course altered to suit current requirements, for example being routed around Neubiberg air base.

In the meantime, long sections of the riverbed were restored, for example in the Hachinger Tal landscape park at the location of the previous airfield.

The stream currently flows along the western edge of the Ostpark and then crosses under Heinrich-Wieland-Straße, and ends after a further 120 m in an intake with an automatic rake to remove fouling from the grate.

From the underground intake to the Josephsburg U-Bahn station pavilion at Kreillerstraße, there is already a dry riverbed, but the original plans to route the stream to the surface at the 2005 Bundesgartenschau failed due to budget insufficiencies.