Increasing occurrences of flash flooding poses significant social and economic threats to Barcelona. Approximately 65% of the population reside along the coast. Many rely on beach assets to attract 35 million annual visitors that buttress the city’s 7.1 billion EUR tourist sector. Both residents and tourists are vulnerable to late-summer and early-autumnal flash floods of intense rainfall events that that exceed the capacity of urban drainage systems designed for 55% less loading. Government efforts do not account for non-resident population needs by focusing primarily on residents’ safety following floods. Regular flash floods in Barcelona indicates an urgent need to develop a water sensitive strategy that comprehensively accounts for point source pollution in this vulnerable coastal region, as well as for its socioeconomic profile. While Social Vulnerability Indices have been developed for climate change-related disasters over the past fifteen years, these indices are designed for use at a national scale and overlook the needs of seasonal residents (e.g. short-term residents and tourists) in social profiling. This research broadens the scope of social vulnerability indices to factor in temporary resident needs in disaster planning at a regional scale. The social vulnerability index can help government planners include floating population groups in post-disaster management efforts.