Fostering citizen and stakeholder engagement through Brazil's dam-breach alert and evacuation drills

Dams are critical infrastructure that provide essential benefits such as water supply, energy, flood control, and are commonly used for storing tailings. Brazil suffered tragic tailings dam breaches, in Mariana in 2015 and  in Brumadinho in 2019, which caused several fatalities and reshaped national awareness. Consequently, stricter Brazilian legislation now mandates the implementation of frequent dam-breach alert and evacuation drills. Depending on the reservoir's purpose and risk classification, dam owners are required to prepare the population within the Self-Rescue Zone (SRZ), to plan and conduct these exercises annually in coordination with public organs. The SRZ is a hydrodynamically mapped area from which the population must evacuate on their own in case of an emergency because there is not enough time for competent authorities to act on their behalf. Beyond testing operational readiness and efficiency, evacuation drills function as participatory governance tools that integrate citizens, institutions, and technical experts in the co-production of knowledge about local risk, preparedness, and response capacities. The process begins with preparatory workshops to contextualize risks, clarify roles, and train both institutional actors and community members. On the drill day, a predefined failure scenario guides decision-making and communication flows, culminating in the activation of the siren and the self-evacuation of the population along established routes toward predefined safe points. This work presents insights from two  evacuation drills conducted in 2024 and 2025 downstream of the Ibirité water reservoir (MG-Brazil). The associated SRZ encompasses approximately 3.405 ± 337 residents and workers. Throughout the exercise, data such as response times, arrival times, and qualitative feedback were collected through observation and post-drill surveys. Regarding stakeholder response, internal procedures, from the identification of the imminent hazard to siren activation, took 22 and 25 minutes for the 2024 and 2025 drills, respectively. These durations, while demonstrating preparedness under simulated conditions, also highlight that actual events could involve longer internal process times due to the inherent awareness built into an exercise scenario. Low rates were registered for community participation, 2.4 ± 0.2% in 2024 and 2.3 ± 0.2% in 2025. Population mobilization and evacuation times were registered for each participant. Mobilization time was between 5.8 ± 5.4 minutes in 2024 and 5.9 ± 5.7 minutes in 2025. Total evacuation time ranged from 13.0 ± 7.7 minutes to 13.5 ± 8 minutes after the alert, respectively in 2024 and 2025. Furthermore, descriptive findings from post-drill surveys indicate that 94% of the participants reported feeling better prepared for a potential flood risk. Key challenges include improving community engagement, effectively reaching socially vulnerable groups, and translating the knowledge gained during drills into sustained preparedness practices. Ongoing research investigates the social and spatial factors influencing participation and evaluates whether these practices effectively enhance protective knowledge and motivation. Overall, this initiative exemplifies how participatory mechanisms can bridge the implementation gap in disaster risk governance within the Global South, where institutional capacity and risk communication often remain uneven. The findings contribute to broader international discussions on integrating citizen and stakeholder knowledge into evidence-based and socially embedded risk governance.