Water quality degradation in harbour domains can have an important negative impact from an economic,
touristic and environmental point of view. In that sense, water quality management is becoming a main
concern for harbour managers. In this paper, we present the research behind the initiative started in Spanish
harbours to control water quality degradation due to accidental pollution. This management system is already
operationally running in the Barcelona harbour (NW Mediterranean Sea). The system is based on a recent
published risk assessment, which takes into account not only the different activities in the harbour and their
inherent risk of accident but also the physical behaviour of harbour waters.