Suburban watercourses receiving sewage effluents often are low flow, and not modified, as is the case of large, receiving ones. The impact of chemical pollutants on biodiversity, as well as the effectiveness of ecosystem recovery and self – purification, need careful attention. The aim was to assess the macroinvertebrate responses to receiving a wastewater treatment plant (WWTP) input along a downstream gradient. We studied the variability and recovery pattern of macroinvertebrates in six sections located along a sewage receiving stream continuum. The comparison of chemical parameters showed significant differences in the pH, BOD₅, N-NH₄ and PO₄^3-. At sites 100, 300 and 500 m downstream of the WWTP, the persistently high amount of pathogenic coliform bacteria indicator, testified to the high impact of bacteriological pollution of sewage on the receiver. Based on 18013 macroinvertebrates, nonmetric multidimensional scaling showed differences between the assemblages at the sections upstream of the WWTP, and located downstream. Effluent discharge affected the macroinvertebrate, causing its quantitative index (abundance) decrease of 7% and qualitative index (EPT) of 26% at the site of the sewage discharge. The recovery pattern was observed in a gradual increase in macoinvertebrate indices at the sites located downstream from the WWTP, which at distances of 300 m and 500 m from the discharge site attained comparable values to those at the reference sites upstream of the WWTP. The populations of the most sensitive taxa were not fully restored with increasing distance from the WWTP, even at a distance of 500 meters, but instead were replaced by more resistant taxa. More attention should be paid to the study of the impact of wastewater discharge from suburban wastewater treatment plants on receiving watercourse biodiversity, and ecological water conditions, especially in the case small and low flow sewage receivers, where the self-purification processes are difficult.