Abstract
The monitoring of selected physicochemical parameters and chemical composition of water was conducted in 2017-2018 in the Lubrzanka river and the Cedzyna reservoir (Swietokrzyskie Mountains, Poland). The results indicate that the impact of reservoir on the quality of river water depends on natural characteristics of the catchment as well as on the present anthropogenic pressure. Retention of water in the reservoir caused seasonally diversified changes in analysed parameters, including an increase in water temperature, retention of major ions, nutrients and trace elements. Further research is needed to assess the risk of contamination of lower course of the river with metals deposited in reservoir’s bottom sediments.