Due to mining and industry, streams in the densely populated Emscher catchment were once open sewage canals. A steel production company dominated the landscape until 2001, forcing the stream to flow in an underground channel. After the industrial area was abandoned, the factory was demolished and – after much debate – developed into a multipurpose lake. Large-scale restoration has returned the stream and much of the catchment to a natural state, including the ecological hotspot Lake Phoenix.