Improving ecohydrological functions of urban areas and urban streams – Extending immission-based approaches towards an ecosystem services perspective

The contribution deals with the interaction of urban drainage systems and receiving water bodies of storm water effluents. It introduces and discusses two possible approaches of Nature-Based Solutions (NBS) to improve ecological functions of urban areas: 1. Reduction of runoff from rainfall excess through nature-oriented urban infiltration, storage and evapotranspiration strategies; 2. Improving urban water bodies’ ecohydrological capacity to buffer and filter pollution from combined sewer overflows. These approaches are considered from an immission-oriented viewpoint. This viewpoint is extended towards an ecosystem services approach considering not only the effect on receiving ecosystems (e.g. an urban stream) but also the effect on ecosystem service provision. The talk presents ideas, case study examples and on-going work. It aims at initiating a discussion on improving ecohydrological functions of urban areas and water bodies. It addresses practical design issues as well as policy instruments to highlight the variety of on- and off-site benefits (ecosystem services) from ecohydrological improvements