Analysis of the robustness of the French flood warning system: a study based on the 2009 flood of the Garonne River

The reorganisation of the French flood warning system initiated in 2002 expresses the State's motivation to improve the anticipation and reactivity of crisis management services. However, the example of the 2009 flood in the Garonne Marmandaise territory highlights vulnerabilities in institutional warnings, resulting partly from the reorganisation of the flood warning system. Although this flood was perceived as ordinary by the mayors, several communities were flooded and became isolated. The present study focuses on adjustments carried out by stakeholders during the flood warning process. The concept of robustness is applied to the French flood warning system through the analysis of (1) the resources mobilised by stakeholders to process the warning, (2) the constraints that hinder their actions, (3) the interactions and the efforts of coordination that link stakeholders within the system. Our results indicate that the robustness of the flood warning system partially rests upon the coping capacities present at a local level. Indeed, these coping capacities allowed institutional vulnerabilities to be overcome during the 2009 event. In addition, feedback engaged after the 2009 flood favoured interactions and sharing of lay and scientific knowledge among the French flood warning system stakeholders. These interactions reinforced both the French flood warning system's robustness and coping capacities at a local level.