This work aimed to study the main environmental conditions of the hydrographic basin of Lajeado da Represa, municipality of MarcelinoRamos, RS. For that, the physical aspects (geomorphology, climate, soil, geology, hydrography, vegetation) and water quality assessment were considered. To characterize the water quality, the following parameters were considered: color, turbidity, STD (total dissolved solids), hardness, pH, electrical conductivity, chlorides and total fecal and coliforms. Samples were collected at the Lajeado da Represa springs and at some points, mainly in places where evidence of garbage and sewage deposits existed. The results obtained reveal environmental alterations,
