Renewal of the Deininghauser Stream, Castrop-Rauxel

Since the 1920s, the course of the Deininghauser stream had been converted to an open wastewater canal due to the mining activities, straightened and routed to the main course of the Emscher as a central wastewater canal for the Ruhr area. The wastewater and surface water were not separated in the Emscher system, with open courses of untreated wastewater totalling roughly 350 km in length. IBAIBA Internationale Bauausstellung Emscher Park selected the stream as a pilot project for the ecological renewal of Emscher feeder rivers.

Like other former river and stream courses in the Emscher region, the Deininghauser stream was an open, untreated wastewater course. With a total length of 9.5 kilometres, it led the wastewater through Castrop-Rauxel and flowed into the Emscher via the Landwehr stream. The renewal was intended to restore the stream to its natural condition and network it with other biotopes via streamside meadows. For this, the contaminated water and clean water had to be separated and new – now underground – wastewater canals had to be built. The location of the stream course in the heavily populated urban area of Castrop-Rauxel was a particular challenge. By uncovering the previously piped sections, the stream was to be brought to life as an urban waterway. The renewal included building cycle paths, bridges and new connecting routes between the landscape and the city. Today, no one would think that this was a former wastewater canal. The ecological renewal forms the backbone of an outstanding new landscape space in the eastern Emscher region.

The overall Emscher renewal project was started in 1992 by the water industry cooperative Wasserwirtschaftsverband Emschergenossenschaft, and is to be completed in the years to come. The project no longer focuses solely on the water routes through the Ruhrgebiet region. A new riverside landscape is developed to the left and right of the Emscher, with spaces for art and nature. The extensive time span shows that the renewal of the Emscher system is a long-term project extending far beyond the overall duration of the IBA.