The work consists of the creation of a hydraulic structure to collect runoff on both sides of the RN 106 and to return it to the quarry basin of the antiquail (500 000 m³ of storage at the 2022-2023 deadline and 1.8 Mm3 by 2033). 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.