The Aiterach ( headwaters ) below Mühlhausen, looking towards the downstream
The Aiterach or Aitrach is a right tributary of the Danube in Bavaria, with a length of 36 km.
The meaning of the name is derived from the Indo- oid for swell and the Old High German word for water aha. So the river name means as much as " intumescent water ". The river was eponymous for the location Aiterhofen ( courtyard at the Aiterach ).
The Aiterach rises above the village of Mühlhausen, strictly speaking, at Ottending ( Mühlhausen district, community Mengkofen ) and flows east of the village Unteröbling ( Straubing, district Ittling ) in the Danube at river kilometer 2314 ( here measured from the mouth ). In the last part of almost 1.8 km on the right side runs parallel to the Aiterachkanal, mostly at a distance of 45 meters, but then increases in a left loop of Aiterach up to 360 meters, and flows 200 feet below the Aiterach into the Danube.
On the outskirts of Mulhouse opens on the left side of the Leinbach was the first major tributary in the Aiterach, after Leinbach hamlet of the municipality Weng ( district Veit Book) is named.
The Aiterach follows from Mulhouse to Mengkofen the state road St2138, and continue until the Salching St2141, as well as in Aiterhofen for a few kilometers, the B20.