Screening is intended to trap more or less voluminous matter and waste of all kinds contained in the inlet channel of a hydraulic structure or at the stage of pretreatment of domestic wastewater, agricultural wastewater or industrial wastewater, for allow their extraction then storage in bin and evacuation to a treatment channel.

One or more float level switches make it possible to regulate the level of water upstream or downstream of a screen, which makes it possible to determine the level of fouling of the screen.