The Emscher now drains rainwater and purified wastewater. As a consequence, it was possible to transform the canalised river bed into a valley with possibilities for nature development and recreation. Locally, the systems were adjusted to the regional objectives: improvement of the water quality and the experience value of the Emscher and the reduction of waste discharges into the Rhine river. Peaks in rain water discharge are capped as much as possible. This is possible through the application of various measures such as infiltration, temporary storage and delayed outflow. The scale and the approach of the project make it an important example, nationally and internationall