The studies of Lake Będgoszcz and the adjoining waters (of the rivers: Krzekna, Ostrawica and the Nieborowski Canal – the River Bielica) were conducted in the years 1996–2001. Lake Będgoszcz was fund to be a polimictic body. Oxygen conditions in the lake waters were similar during the entire study period. The surface waters were usually better oxygenated, though. Clearly, the vertical distribution of oxygen occurred in the summer. The least favourable oxygen conditions occurred in the autumn, and the minimal amount of dissolved oxygen occurred in the bottom waters (4.8 mgO₂·dm^-3). The organic matter and chlorophyll ”a” contents in the waters of Lake Będgoszcz proved considerable trophy of these waters. The biggest concentration of total nitrogen was found in the surface layer in the summer (mean 2.69; maximum 4.81 mgN·dm^-3), whereas, its lowest value in the same layer was recorded in the winter (mean 1.96 mgN·dm^-3). The biggest concentrations of total phosphorus were observed in the surface layer in the spring (0.52 mg·dm^-3), whereas, the lowest value in this layer was recorded in the autumn (0.19 mg·m^-3). The conducted investigations proved that Lake Będgoszcz was hardly resistant to degradation and its drainage basin easily activated loads of the biogenic matter deposited in its area. This water body has been subject to intense eutrophication. It shows hypertrophic characteristics. Lake Będgoszcz is under the threat of nitrogen coming from farming sources. The waters in the studied lake stay outside classification according to the guidelines of the basic lake monitoring system. Habitat conditions prevailing in the lake during the study period did not pose any threat to ichthyofauna. Therefore, the lake may be classified as a pike-perch lake according to fishing typology.

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