Since 1980, Spain has introduced urban regeneration plans in various cities with the aim of integrating the river environment into the urban system. This process has proved most challenging in cities whose rivers present extreme features, as is the case with Terrassa (Catalonia, NE Spain), a medium-sized city (215,000 inhabitants in 2013) whose three river courses are prone to flash flooding. Through the critical analysis of urban planning undertaken in the city from the fifties to the present day, we show that the urban evolution of each of the three intermittent streams has differed significantly. Thus, while the plans affecting el Torrent de Vallparadís have led to the construction of Terrassa's central park, the plans for la Riera del Palau and la Riera de les Arenes have impeded, in their own ways, full urban integration.