It has been established that in all sections of the rivers under study, cases of pollution by biogenic substances have been identified, which differ both in the concentrations of their excesses and in the cases of their detection. The excess in the nitrogenous group dominates in the tributaries: Bull, Ikel, Botna. In the Reut tributary, the groups of nitrogen and phosphate pollutants are equal. The most unfavorable sections of the river were identified, which were Botna, Ikel, where excesses were recorded for all nutrients and had a degree of pollution higher than in the tributaries of the Reut and Byk. It is shown that the assessment of water quality in rivers from an ecological point of view, inflows according to the same indicators had different quality classes. However, class V was defined in all river ecosystems, which indicates the fact of an increased anthropogenic load, associated primarily with the entry of pollutants into the rivers, both recent and permanent pollution