Deininghauser Bach

Castrop-Rauxel

With a total length of 9.5 km, the Deininghauser Bach river, which flows into the Emscher river, drains a 17.2 km² watershed in the city of Castrop-Rauxel. As long ago as the 1920s and 1930s, its natural course had been concreted, expanded and straightened as an open wastewater drain. Seventy years later, in 1992, its environmental restoration, with a near-natural design, began.

The objective of the rehabilitation within the framework of the IBA Emscher Park Project was the restoration of the watercourse into a small river, typical of this area. Longitudinal and cross-linking via meadows should incorporate other biotopes in the Deininghauser Bach watershed. The prerequisite for this was the separation of wastewater and clean water and the construction of wastewater drains. On the one hand, clean tributaries from adjacent areas should be incorporated with the same reliability as before, on the other hand, as an urban waterway, the Deininghauser Bach should also offer recreational activities near to the city.

Restoration of the headwaters has been complete since 1996. The watercourse quality classification of this section is now deemed as only ‘moderately’ polluted and existing subsidence damage due to earlier coal mining has been remedied. The restoration measures included the levelling out of steep embankments and the direction of the river course in diverse meanders through the meadows.

The entire underground wastewater drain was completed in 2005 and a further 1.3 km section of the river was environmentally restored. Due to restrictions, this section was only marginally widened and has maintained large parts of its linear direction. The restoration of the last 3.8 km, to the point at which it flows into Landwehrbach river, is still planned. Furthermore, the exposure of previously covered sections will make the river accessible as an urban waterway.