25. A groundwater withdrawal facility designed to capture a natural resurgence of groundwater using a horizontal drain must meet the following conditions:(1) the drain must be buried at least 1 m deep upstream from the natural point of groundwater resurgence so as to collect the water before it surfaces;
(2) the drain must be connected to a watertight reservoir;
(3) the reservoir must stand at least 30 cm above the surface of the ground and must be equipped with an overflow, directing water that is not withdrawn towards the natural outlet of the resurgence;
(4) the ground above and for at least 3 m upstream from the drain must be graded so as to prevent runoff towards the drain or the infiltration of surface water;
(5) the location of the drain, and in particular of its extremities, must be indicated by visual markers.