Magagna beach is a small urban settlement for summer and weekend recreation, installed on a typical marine accumulation plan of the Patagonian coast, with strong influence from marine erosion and mass removal. This article describes how inhabitants have sought to mitigate the impact of both forced functions on their homes and other household assets, and shows that individual responses have had to be progressively complemented by collective actions and cross-sectoral approaches, as local and regional use of space grew. Our work reconstructs environmental partner history over 40-50 years and interprets it in terms of risk management and coastal management, showing that the physical vulnerability of endangered contexts was reduced through structural measures, and that social, political and institutional vulnerability was reduced by increasing internal cohesion and leadership. This sequence of events is only expected under two specific conditions: living spaces with limited carrying capacity, and a self-propelled local community. In the absence of a local community with self-adjustment capacity, very different results should be expected, even with similar constraints on the physical environment.