Urban Planning and Stormwater Management in Rome. Guidelines for an operational integration between the Basin and the Local Plan

The Metropolitan City of Rome is a conglomerate of 15 comuni with a total surface area of over 1200 km2. It occupies about 3% of the surface of the Appennino Centrale Basin, to which it is administratively circumscribed, being the largest commune of which it is composed. From the 1930’s to the present, it has undergone an enormous demographic expansion, favoured by the 1931’s Regulatory Plan, increasing its territorial extension tenfold until today (Oliva, 2000). With regard to the preservation of water resources, the Piano di Bacino (Basin Plan), besides being the most sovraordinato of all the instruments regulating the territorial governance in Italy, is the normative instrument that has prescriptive and managerial attributions over them, being in order of subordination, the communal level (livello comunale) four levels below it. Even though solid legal structures are necessary in complex realities (Romano, 2020), it is also important, in the face of climate change and urban realities subjected to an anthropisation that blocks the metabolism of the biotopes where cities are built, to find operational mechanisms (McVicker, 2024) that streamline the operational relationship between levels of governance when it comes to managing natural resources, among them water. An operational integration carried out within the framework of an strategic planning to allow the consolidation of solid infrastructures durable beyond contingencies, from a Green Based perspective that takes into account the qualitative restitution of the Nature Based structural solutions (Andersson et al., 2014; Verburg, Selnes & Verweij, 2016). Within this framework, this contribution aims to synthesise some guidelines for the operational linkage between the Piano di Bacino and the Piano Locale of the city of Rome (NPRG, 2008), in order to favour a systemic consolidation of Green-Blue Infrastructures, that mitigate adverse physical and social events and favour urban resilience through a sustainable urban water governance.