An Assessment of Water Reserve Changes in a Small Dam Reservoir: The Case of the Przebędowo Reservoir

This paper presents the results of a study conducted in the immediate watershed of the Przebędowo Reservoir. The analysed reservoir is located in the Wielkopolska (Greater Poland) Voivodeship and lies within the Surface Water Body (SWB) named Trojanka (Struga Goślińska) with the national code RW600010185969. The conducted research and analyses confirmed that, for small reservoirs with the dam operating in flow-through mode, water levels vary only slightly from the normal pool level (NPP). A regular pattern was also observed, often in dam reservoirs where inflows exceed outflows. It can be concluded that, in addition to evaporation from the water surface, the reservoir's partially fed nature significantly influenced this situation. Calculations of the correlations between changes in reservoir water storage and inflows and outflows revealed a relatively strong relationship. However, no direct correlations were found between increases in water storage in the reservoir in question and one of the factors of vertical water exchange, namely precipitation inflow into the reservoir.