The paper describes the planning process for the pilot implementation of a decision support system (dss) for global control of sewage pump stations in Berlin, which is going to be realised by the end of 2006. The objective of the control concept is to systematically manage in-pipe storage capacities in order to reduce cso. The paper presents the preliminary assessment of the system’s control potential based upon the analysis of operational figures and numerical simulations. Furthermore, the structure of the decision support systems procedure is illustrated.

In Berlin, Germany, the demand for enhanced protection of the environment and the growing economic pressure have led to an increased application of control concepts within the sewage system. A global control strategy to regulate the pumpage of the combined sewage system to the treatment plant was developed and evaluated in a theoretical study. The objective was to reduce CSO. In this paper an extension of the existing control algorithm by information from online rainfall measurement and radar nowcasting is described. The rainfall information is taken into account by two additive terms describing the predicted volume from rainfall runoff. On the basis of numerical simulation the potential of these two complementary forecast terms in the global control algorithm to further reduce CSO is evaluated. The investigations are based on long-time simulations that are conducted with the dynamic flow routing model InfoWorks for three subcatchments of the Berlin drainage system. The results show that at the current Berlin system a CSO reduction of only 0.8% is possible. The effect of the forecast terms is limited by operational constraints. Limits are set to both, the delivery from each individual pump station and the total pumpage to the treatment plant.

The use of numerical models has become state of the art in planning, designing and analysing the urban sewage system. To evaluate the functioning of a complete system and to study the interaction of its subsystems integrated models can be used, incorporating catchment area, collection system, wastewater treatment plant and also receiving water and groundwater body. The paper introduces a structured, problem-oriented methodology for the setup of integrated models. Considering the case study of Berlin the introduced approach is illustrated. An emphasis is placed on the necessity for the selection of adequate model components. In Berlin this aspect is of particular importance for the modelling of wastewater transport through pressure mains that is governed predominantly by pump stations. Finally, the use of the Berlin model for the evaluation of a global pump station control concept is presented. It can be shown that besides the possibility of total system analysis and evaluation a major benefit from integrated modelling is the consideration of the interaction of the system’s subcomponents.