Favorire la progettazione di Green-Blue Infrastructures per una gestione sostenibile delle acque meteoriche: un'analisi comparativa internazionale

Extreme storms caused by Climate Change have considerable repercussions on water management, making territories, primarily urban areas, increasingly vulnerable and subject to different forms of risk, such as flash floods. The increase in frequency and intensity of these events requires rethinking water management practices and renovating traditional drainage systems, too often undersized compared to today's rain loads. In this sense, the Green-Blue Infrastructures (GBI) design represents an innovative opportunity for the diffused management of pluvial runoff, particularly favouring stormwater infiltration into the soil and reducing possible contamination episodes. Integrating nature-based solutions with more structural interventions allows GBI to respond effectively to the climate changes underway, thus favouring a multifunctional approach to open space planning. This study investigates the most effective ways to facilitate this transition and integrate GBI into ordinary urban planning practice. The paper proposes a comparative analysis of two international cases commonly recognized as best practices: Copenhagen (DK) and Portland (US). Particular attention is paid to investigating the urban planning tools adopted to guide this transition towards the GBI approach, the stakeholders involved, and the fiscal mechanisms implemented.