Abstract
The aim of this paper is to evaluate the hydrological conditions and chosen physical and chemical parameters of water quality in four chosen fluvial lakes, two of which are connected to the Elbe River stream by surface and two communicate with the Elbe River only by ground water at normal water levels. For water quality evaluation, the following parameters were chosen: conductivity, pH, alkalinity, biochemical oxygen demand, chemical oxygen demand, amonia nitrogen, nitrate nitrogen, total nitrogen, total phosphorus, phosphates and chlorophyll A.
The results show that lakes communicating with the Elbe River are directly influenced by the river in both, the hydrological regime and water quality. This is reflected especially in a great influx of nutrients.
All the chosen lakes are largely afflicted by eutrophication.