As part of the methodology, a field study was also carried out in the region immediately affected by the dam’s failure in November 2015. The results – notwithstanding temporary positive effects on education and health indicators, the low diversification of economic activities, and the small proportion of government budgets assigned to environmental management – show the lack of sustainability of the current local development model in the medium and long term. There is still some social and environmental damage that has not been measured, and this interferes strongly with strategies for reparations and compensation for affected individuals and groups. The authors identified the following failures that may have contributed to the accident: flawed inspections following the issuing of environmental licenses; a lack of technical analysis by the environmental regulator of reports submitted by the company; and a lack of thorough analysis of requests to adjust the dam’s license conditions. Local residents affected by the accident have experienced a context of “social stigmatization” in Mariana, as many people in the region believe they are the main cause of the shutdown of Samarco’s activities and the consequent local economic crisis. Thus, the authors infer that the sustainability of development has not been a priority for local public managers. Furthermore, the study presents an analysis of all the stages in environmental licensing, and it shows how instruments for evaluating social and environmental impacts are fragile in Brazil. Based on their research, the authors suggest that the regulatory authorities invest their efforts in more rigorously applying preventive instruments, such as properly conducted environmental licensing, appropriate ecological and economic zoning, and high-quality environmental impact assessments. The study identifies the urgent need to examine productive alternatives for Mariana and other municipalities affected by mining activity in Minas Gerais and across Brazil. It also shows the need to rethink the model of implementing and operating large projects, which is currently applied disproportionately in Brazil, without considering the different groups involved in a coordinated way.