"IMPROVEMENT ON FACILITY FOR REMOVAL OF MATERIALS AND / OR POLLUTING SUBSTANCES CONTAINED IN WATERCOURSES", applied to facility comprising : the implementation of a sandbox arranged at the bottom and in a stretch of the watercourse, followed by a floating garbage fence arranged substantially transversely to the watercourse; whereas downstream and at a certain distance from this garbage fence is provided a suspended and transverse metallic structure to the watercourse, in which curtains for selective injection and automatically set in motion are mounted, arranged spaced and interspersed by homogenization diffusers, these curtains are responsible for the injection of coagulants; by the injection of polymers into the watercourse to be treated, and ahead there is a phase for release of microbubbles of air, causing a flotation of these aggregate particles; allowing that from this flotation stretch arises, along the watercourse, a superficial agglomeration of the floated material, and the conduction by flexible and longitudinal barriers formed by synthetic membranes of this floated material to a transverse alignment of dredging modules, that extend through the entire watercourse's width promoting the concentration of floated material and its removal. This improvement consisting of all equipment (3, 4,7) originally installed transversally the watercourse, which are subject to partial or total removal from this transverse condition, allowing the clearance of part and/or entire bed of the watercourse.