In a context of climate change, coastal territories are more and more subject to flood and erosion hazards. In the meantime, the concentration of issues in these areas is increasing the risks. Thus, setting up erosion and flood management strategies becomes essential. In France and in Quebec, coastal risk management is reflected by the establishment of public policies, affecting closely or remotely this topic. Their analysis offers the possibility to understand, and with which tools, the way different administrative levels, in particular the Public Inter-municipality Cooperation Establishments in France and the Regional County Municipalities in Quebec, manage these risks. The functioning of the two systems is highlighted, on the one hand by a thematic comparison of public policies, and, on the other hand, using an archetype of territory, concretizing their application on the ground. These two approaches make it possible to underline the particularities and similarities of the two systems but also their strengths and weaknesses in the implementation of sustainable public policies applied to adapt to the consequences of climate change on the coasts.