Impacts of Combined Sewer Overflows on Urban Waters: Challenges and Solutions for European Cities

6November 2013

Final Workshop of KWB Project MIA-CSO at the International Water Week in Amsterdam

Urban surface waters play an important role for the diversity of a city, the recreation of its citizens, the urban microclimate and in some cases also for drinking water quality. However, urban lake and river ecosystems are exposed to various stressors – among them combined sewer overflows (CSO) – whose impact is expected to increase with climate change and ongoing urbanization. Aim of the workshop was to identify current and future challenges for urban waters and discuss the legal framework for the protection of surface waters from CSO impacts. Management tools and early-warning systems for tackling different kinds of impacts were introduced.


  • Current and future challenges for tackling CSO impacts on surface waters
    Andreas Matzinger (Kompetenzzentrum Wasser Berlin)
  • Policies and legislation for CSO control and the protection of surface waters
    Pere Malgrat Bregolat (EUREAU European Commission on Waste Water and
    CLABSA, Spanien)
  • Reduction of CSO impacts in Berlin – Regulatory requirements and management responses
    Bernd Heinzmann (Berliner Wasserbetriebe)
  • SIAAP’s stormwater management policy
    Jean-Pierre Tabuchi (SIAAP Frankreich)
  • An impact-based planning instrument for CSO control in Berlin
    Mathias Riechel (Kompetenzzentrum Wasser Berlin)
  • Optimising sewer operation to reduce CSO impacts in Denmark
    Morten Grum (Krüger A/S, Dänemark)
  • Integrated management of coastal sewer network discharges
    Marie-Christine Huau (Veolia Environnement)