Disaster-resilient communities against floods: the “swarm” concept as a frame for effective small-size cooperative and distributed measures working at the urban scale: a design simulation for Como

The work presented here investigates the possibility of an additional strategic tool designed to reduce the impact of flood disasters in urban areas, enhancing both the practices of sustainable urban planning and civil protection plans, and cooperating with the implementation of stronger and smarter climate change adaptation actions. The study conceptualizes an innovative approach, here called Swarm Flood Proofing , that originally combines the methodological use of both temporary and permanent small scale flood proofing techniques for the defence of built environments, as a whole, overcoming the usual application of such techniques in small or isolated portions of built-up areas or in an impromptu manner. This approach provides its potential users a strategic option to be compared with flood control alternatives, such as non-structural measures, major structural measures and green infrastructures, to fight against floods in a context of increasing frequency of stricken territories. In the framework of the GESTI.S.CO. project (Italian acronym for “Management of emergencies and disasters without borders”), co-funded under Italy-Switzerland Interreg EU Cooperation Programme, the urban area where both the analysis and design of our study were carried out is Como (Lombardy Region, Italy), where a complicated attempt to build a big infrastructure to defend the city from floods, coming simultaneously from its lake and the surrounding hills, has been underway for more than thirty-eight years. The Swarm Flood Proofing approach conceived and developed here proved to be potentially able to counteract upstream waters and downstream lake-waters in Como, in this way protecting citizens and goods of the city, through the widespread cooperative use of microscale temporary measures and micro-works. Based on the analysis of such case, it appears that, under verified conditions and assuming detailed hazard and risk analyses, the Swarm Flood Proofing approach could also be helpful in defending other fragile urban contexts and local communities; it is especially effective where implementing defence choices, based on large-scale infrastructure (green or grey) or non-structural measures alone, becomes complicated not only for financial reasons, but also due to issues often affecting spaces where people settle and interrelate such as: landscape safeguard needs, important cultural heritage values, high densities of buildings, infrastructures and people, land use and environmental components to be protected. Swarm Flood Proofing, combining and exemplifying knowledge coming from multiple domains, allows a proper interpretation of an original way for planners and decision makers to favour the growth of disaster resilience-oriented local communities.