Preliminary Studies of the Water Quality in the Reservoir Wielkopolska at Different Times of Operation on the Basis of Selected Indicators
Department of Hydraulic and Sanitary Engineering, Poznan University of Life Sciences, 60-637 Poznań, Poland
Department of Construction and Geoengineering, Poznan University of Life Sciences, 60-637 Poznań, Poland
Natalia Walczak   

Poznan University of Life Sciences, 60-637 Poznań, Poland
Data publikacji: 01-02-2021
J. Ecol. Eng. 2021; 22(2):77–85
The demographic and urban expansion of the nineteenth century led to a significant reduction in water resources. One of the considered solutions to this problem was to retain water in reservoirs. Over the years it has been recognized that the construction of small reservoirs can bring greater benefits than large ones. Large reservoirs are not only associated with substantial economic costs, i.e. for the purchase of land, but they also do not sufficiently serve as the components of a flood protection system. They are also of minor importance in the production of so-called ''white energy” (Lehner et al., 2005) and may have a negative impact on the environment. The size and age of reservoirs as well as the type of water dams and their work regime affect the scale of changes in the natural fluvial environment (Robinson et al., 2003). Small reservoirs are a basic element of small water retention, in which water quality depends to a large extent on their location, the way their catchment areas are managed and the functions they perform (apart from typical retention reservoirs). The catchments used for agricultural purposes may be susceptible to accumulation of biogenic substances (nitrogen and phosphorus), and other pollution (Hejduk, 2010; Kanownik et al., 2013; Kasperek et al., 2013; Wiatkowski et al., 2013). The article initially tested the quality of the water in three reservoirs, different period of operation with use of selected indicators. For the purposes of research and this resultant publication, water quality was tested in three reservoirs differing in operating times. It was assumed that the study period covering autumn, spring and early summer was the period with the most visible changes in concentrations of pollutants. Samples taken from the reservoirs were analysed by determining in turn biological oxygen demand (BOD5), ammonia concentration (NH4), phosphate concentration (PO4) and total suspended solids. The use of indicators allowed for assessing the quality of water in these reservoirs and comparing it in terms of different periods of their operation.