Wpływ osadnika wstępnego na proces zamulania zbiornika głównego

One of the ways to limit the silting process of storage reservoirs could be the use of so-called preliminary settling tanks. Such concept has been used in construction of Mściwojów reservoir, which is the experimental water reservoir of Wrocław University of Environmental and Life Sciences. Before infl owing to the main reservoir water passes through the chambers of settling tank covered by macrophytes and subsequently through the pre-dam where the pollutants and solids are deposited. This signifi cantly improves the water quality and slows down the silting process of main reservoir. The analysis of sediment transport and sedimentation in Mściwojów reservoir system (settlement tank – pre-dam – main reservoir) shows that during the reservoir operation in 1999–2005 the total amount of stored sediments is about 26 570 m3. More than 2/3 of sediments has been stored in predam and in settling tank. The settlement tank has retained more than 10% of sediments of total sediments that infl ow to the reservoir. While assessing a effectiveness of biological fi lter in form of vegetation (Common Reed) in II chamber of settling tank it can be seen that the most thick layer of about 25 cm has been deposited there. This layer is a half of depth in chamber. The chamber is 50% more shallow than other chambers. It should be noted that the pre-dam together with settling tank is an important element of main reservoir protection against the harmful effects of sediment infl ow. It also diffuses pollution infl ow to reservoir from catchment. Vegetation that was introduced to the tank intensifi es the process of sedimentation. This paper presents characteristics and functions of Mściwojów reservoir system, fi eld research methodology as well as results obtained and their analysis.