PPI — Time of arrival of the flood wave in the event of a rupture of the Poupard Touch Dam — special response plan

The Special Intervention Plan (PPI) is a local mechanism defined in France to protect people, property and the environment, to deal with the particular risks associated with the existence of one or more industrial installations. The term also refers to the document that defines the device. It shall define the means of rescue used and how they are managed in the event of an accident the consequences of which go beyond the enclosure of the risk installation concerned. These arrangements cover the phases of alerting, alerting and intervention, as well as civil security exercises carried out periodically to ensure proper ownership of the system. Within this framework, a submersion zone was defined in the event of a rupture of the Poupard Touch dam. The breaking of a dam results in the formation of a submersion wave resulting in a sharp rise in the downstream water level. Associated with this risk map representing the submersion envelope resulting from a total breakage of the structure was also defined the arrival time of the submersion wave. The latter data was digitised by DDT 79 on the basis of a study carried out by COMPAGNIE D’AMENAGEMENT DES WATS OF TWO SEVRES in 2005 (annexed to the Prefectural Decree of the special intervention plan. It is also present and downloadable under PEGASE. This is geographical information available to the Prefect in the event of a crisis.