The dynamics of river sediment transport reflects morphogenetic processes taking place in the catchment, being at the same time an anthropogenic indicator. The aim of the research is to determine the impact of hydrotechnical structures on the continuity of suspended sediments transport. The research area is the Lower Vistula River with a single dam – Wloclawek, operating since the 1970s. The research included direct measurements of water turbidity in 2013–2016 in characteristic cross-sections of the Vistula River, using commonly used methods. The LISST-25X laser grain composition measurement sensor was also used to collect data, enabling determination of grain size of the suspended sediments. However, on the selected section of the river, modelling of momentary transport of suspended sediments using GIS tools was carried out. There was a significant dynamics of sediments transport in the longitudinal profile of the river, in relation to the diversity of hydrological and morphological conditions of the Vistula River. The impact of Wloclawek Reservoir on water turbidity reduction was determined. The balance of transport of suspended material was related to the processes of erosion and sediment accumulation below the dam. The functioning of the Wloclawek Reservoir in the current system (as a single dam) has a significant impact on sediment transport, which directly determines the course of fluvial processes across the entire Lower Vistula (from km 675 to the estuary) and indirectly in the coastal zone of the Baltic Sea.