A suctioning device for suctioning impurities from the bottom of large artificial water bodies is provided. The suctioning device includes a flexible sheet configured to provide a structural frame; a plurality of first brushes depending from the sheet; a plurality of middle brushes; a plurality of lateral brushes; a plurality of suction points; a plurality of wheels configured to provide secondary support when the brushes are worn out; a plurality of collectors configured to gather the suctioned water into external suction lines; a plurality of internal suction lines configured to conduit the suctioned bottom water flow from the plurality of suction points to the plurality of collecting means; and a coupling device connecting the internal suction lines and the collectors, wherein a rate of the bottom water flow entering the suctioning device is the same or higher than a rate of water flow suctioned by an external pumping system.