The project consists of the creation of a hydraulic structure to collect runoff from both sides of the RN 106 and to return it to the quarry basin of the antiquail. This structure consists of several ditches, speeding and hydraulic frames that will pass under the RN 106 and under the access track of the quarry basin of the antiquail. Once the water is collected in the basin, it will be returned to the Anduze basin (gift of Alès) via a draining device activated once the flood has passed to discharge them at low flow (350 l/s). A system to return an initial flow rate of 2 m³/s so that small floods do not spill into the quarry basin of the antiquail will also be put in place. The intellectual services (managership, CT, CSPS) and studies (naturalists, geotechnical and topographical), the subject of this grant application, will optimise the dimensioning of hydraulic works while integrating the technical constraints related to the great depth of the frames and the maintenance of traffic on the RN 106 and on the access road to the quarry during the work.