The Waschbach rises as "Lindenbach" east of the Wiesbaden suburb of Heßloch. It gets its real name about 3 km after its source. The stream flows in a valley lined with fields and meadows through Kloppenheim and past Igstadt in the direction of Erbenheim, the center of which it then crosses. South of Erbenheim, it continues westward in a narrow valley, accompanied by the Autobahn 66 and (from Igstadt) the Ländchesbahn, which is taken up by the Breckenheim – Wiesbaden line, which in turn serves as a feeder to the Cologne – Rhein / Main high-speed line . These traffic routes use the Waschbachtal to approach the level of Wiesbaden city center, which is located in a basin. After just under 14 km, the Waschbach flows into the Salzbach opposite the Wiesbaden main sewage treatment plant.
The creek is accompanied over its entire length by hiking trails (between Kloppenheim and Erbenheim identical to the Hessian long-distance cycle path R 6), which are easy to walk in every season. Hikers will find an idyllic route throughout, which, however, between Erbenheim and the estuary can no longer be described as quiet because of the motorway.