The coupling of a sewer treatment station - STS - to a treatment plant for the flocculation and flotation of water streams and the insertion of said treatment plant for the flocculation and flotation of water streams into a water treatment station - WTS ", the coupling being of the type carried through by the treatment process defined in patent document U.S. No. 10/167.089, of 06/10/2002 and Brazilian No. PI0105462-7, 06/11/2001 and comprising the installation of the sewer treatment station STS upstream the flocculation and flotation treatment station (10), in such a way that the outlet of said station STS (23) is directly connected to the inlet (11) of the flocculation and flotation treatment plant (10) disposed next to the stream bed (1) or next to and interconnected thereto by means of a varying flow canal. The insertion consists of the dynamic introduction of the process of treatment for the flocculation and flotation of fluid beds, all in a closed canal (200), wherein the flow of secondary streams (E) is dynamically and continuously submitted to flocculation and flotation techniques in an induced flow canal (FE) in the water treatment station.