the purpose of this project management is to carry out studies on runoff and soil water erosion with the objective of setting up developments fighting against these processes. The study covers 4 different sectors: - sub-watersheds of the streets of the Roy valley (95) - watershed of the Bois des Enfers (78) - watershed of the streets of Fontenay-Saint-Père (78) - Sub-watersheds of the rue d'Orgeval-Ecquevilly and Chapet (78)

carrying out studies on runoff and soil water erosion with the aim of setting up facilities to combat these processes