Municipalities of the atlas of floodplains and flood risk prevention plans

The risk of flooding is the predominant natural risk in metropolitan France. Almost half of the municipalities are affected to varying degrees by flooding, as the share of communal areas in flooding areas varies. The risk of flooding is the subject of significant prevention efforts that need to be continued. Controlling urbanisation and reducing the vulnerability of populations in flood zones are among the objectives of the Grenelle of the Environment. Reducing the vulnerability of people in flood zones requires protective measures (e.g.: dikes) and prevention (example: flood risk prevention plans), by reducing the number of people exposed (example: control of urbanisation) and awareness of risk (e.g. preventive information). In some areas, not covered by RIPs, flood zone atlases (AZI) have been established. The AZI is a knowledge document that delimits the flood field of a watercourse on the basis of a so-called hydrogeomorphological method (a geographical approach that studies the natural functioning of a watercourse by analysing the structure of the alluvial plain). These atlases are information material with no direct regulatory scope. Nevertheless, as a flood risk knowledge tool, an AZI can support a refusal of building permits. List of flood risk municipalities classified by river. A municipality may be affected by 3 rivers with flood risk. It may be affected by one or more flood zones and one or more PPRIs, depending on the rivers crossing it. A municipality affected by a PPRI for a river, exits AZI as part of that river.