« With a rainfall of around 80 mm, this last rainy episode generated less disruption than those we usually faced, the outlet, the marshes, still having a significant absorption capacity. , declared the mayor of Challans (Vendée), Rémi Pascreau, at the last municipal council.
Môle and Juisère particularly affected
However, two sectors were particularly affected: “the Môle was flooded first. Municipal teams intervened in the afternoon, from the first calls, to provide sandbags to protect store entrances. This proved insufficient given the height of water on the site” , indicates the councilor.
The second impacted sector is that of Juisière, particularly near Square Jean-Cocteau. “Activating pumping and raising the dike did not stop the flows. 17 homes were exposed to the risk of flooding, without however reporting significant damage. » Other sectors of the city have experienced increased load on wastewater and rainwater networks.
The City therefore faces more recurrent and higher intensity rainy phenomena. “For the first time, the current dike was unable to contain this rainy episode. A saturation phenomenon was identified at the level of the structure under the departmental road, continues the mayor. The flow of the Pont-Habert stream was such that it slowed down the flow of that of the Poctière, which caused a loading of the rainwater networks. »
Short, medium and long term measures
Immediate measures aimed at reducing the vulnerability of residential houses in the Juisière sector will be sought. « In the long term, they could be supplemented by developments on the scale of the Pont-Habert Watershed (4,876 ha) which would be based on a hydraulic study that the Challans Gois community would carry out in 2025, announces Rémi Pascreau. In the medium term, work could also be undertaken, in particular to increase the diameter of the culvert under the departmental road. »
