In this publication the eutrophic level of the reservoir water, based on the chosen methods, was estimated. Additionally, in this publication the quality of the reservoir water (ecological potential, chemical state, state of the water), based on the chosen parameters, was defined. The biological indicators indicated on the significant level of the reservoir water eutrophication (mainly phytoplankton biomass) and on the moderate ecological potential – III class (mainly macroinvertebrates). The physical and chemical parameters didn’t exceed the boundary values for first water quality class. Despite this, the total state of the reservoir water was classified as bad, (biological elements had decided about this and their affiliation to III class of the ecological potential).