Oozing, black, stinking sludge - a pitiful description for a stream, more fit for Dickens than a modern housing estate. Thankfully, the Emscher Park International Building Exhibition (IBA) heralded in a new era for the Ruhrgebiet.

The starting point for the restoration of the Lanferbach was separation of run-off from the adjacent slagheap and a sewage canal out of the stream. The run-off from the renovated and extended Schüngelberg housing estate is detained in a network of staged swale »fields«. Here there is time and space for purification and infiltration - the cleansed run-off in part recharges the thirsty aquifer and in part is released slowly into the Lanferbach.

The soft curves of the stream are a symbol and instigator of a revived habitat. The banks are once again home to dragonflies.

Terraced play areas reuse old brick walls for paving - as much motivated by a sustainable materials strategy as not wanting to deny the past, rather using an industrial heritage as impetus for a new approach. A bridge across the stream from the housing estate to the top of the greened slagheap dramatizes this important connection to an industrial past.