This project aims at finding cost-efficient measures to meet the Water Framework Directive goals for the Dommel River (The Netherlands). Both acute and long-term impacts of the urban wastewater system (wastewater treatment plant and sewers) on the chemical and ecological quality of the river are studied. An integrated model, which proved to be a powerful tool to analyse the interactions within the integrated urban wastewater system, was used to evaluate the measures using the existing and new infrastructure and real-time control (RTC) strategies. In this paper, the incremental implementation of selected infrastructural measures was investigated. Emphasis was put on the first steps, i.e. a modified use of primary settlers, RTC in the southern part of the sewer catchment and in-stream aeration, which resulted in considerable improvement in receiving water quality (in terms of simulated ammonium and dissolved oxygen dynamics) at a much lower cost than initially estimated.