In this project, a use- and decision-supporting real-time measurement system is developed, with which the quality of water in the rainwater sewer can be measured; the RainSense system. With the consortium's innovation, clean rainwater can be safely infiltrated or reused for various purposes, reducing the inferior use of groundwater or drinking water. In addition, with the help of the measurement system, a possible source of the pollution can be detected and it can be tackled so that future pollution is prevented. The long-term results of this project ensure that the quality of Dutch surface water improves. With the developed monitoring system, integrated water management is one step closer.