This operation is a study that aims to identify areas of flood expansion with the aim of contributing to lowering water levels in flooded areas with high stakes. This operation is part of the framework of action of the Local Risk Management Strategy Châtellerault Flooded in a Programme of Actions and Prevention of Floods downstream Vienna. This operation aims to reduce the vulnerability of populations and activities in areas particularly exposed to the risk of flooding in the Loire basin. The operational implementation of the local flood risk management strategy of Châtellerault is defined in the Vienna Aval Flood Prevention Action Programme (PAPI), which was the subject of a framework agreement signed in 2018. This programme consists of 20 actions for an amount of EUR 1,125 million spread over three years. The actions will be carried out by 6 project promoters (Communauté d’agglomération du Grand Châtellerault, Ville de Châtellerault, DDT Vienne, Syndicat de rivière Vienne et tribuluents and EPTB Vienne) and 11 municipalities are associated with the programme. This operation concerns the identification of existing and potential flood expansion areas and the evaluation of their functionalities. This operation is part of the Flood Prevention Action Programme (PAPI Vienna aval) Action 6-2. This operation is submitted under Action 4 of the ERDF Loire POI.