The paper presents the build-up of a model for the integrated simulation of the sewage system of Berlin, Germany, focusing on the catchment of the wastewater treatment plant Ruhleben. The Ruhleben catchment, draining 185 km² and a population of 1.38 million inhabitants is characterised by its high portion of combined sewerage. The model comprises the collection system, pump stations, pressurised mains and the wastewater treatment plant. Hydraulic and quality processes are taken into account. A preliminary assessment of the sewage system and the analysis of historical operational data showed a high potential concerning global real-time control of the pump stations. Three different global control scenarios have been studied on the basis of a long time simulation over 50 days and compared with a local control regime. The results show that the coordinated operation leads to a reduction of total emissions. Main improvements can be achieved concerning the discharges from combined sewer overflows. These improvements are of major significance due to the high hazard potential of combined sewer overflows.