Septeuil () is a commune in the Yvelines department in the Île-de-France region in north-central France. River Septeuil is traversed by a small river, la Flexanville. This waterway flows through eight other communes for a total distance of . The Flexanville is a tributary of the Vaucouleurs which in turn empties into the Seine. See also Communes of the Yvelines department References Communes of Yvelines