Environmental protection issues are often considered as a toll to be paid and not as a proactive development engine in urban planning. The issue of green areas needs to be re-interpreted as a real infrastructure, which is able to provide tangible benefits to the health and safety of citizens. These aspects represent fundamental issues of the applied research, which should explore methods and techniques able to provide the ecological concerns with the ability to operate efficiently. This paper aims to provide an answer to these questions focusing the attention on the greenery in the city and on one of its most important ecosystem services, which is mitigation of flooding events. The experimentation was carried out in an urban area, verifying, in quantitative terms, the role of the green, engineered with some SUDS, to mitigate the hydrological alteration that the urban development involves. Finally, two proposals have been presented to move from traditional planning based on normative standards to a more flexible, site-specific performance-based planning
