Article presents the impact of anthropogenesis on the aquatic ecosystem of the Brda River estuary. Studied section is part of the E-70 international waterway, which is connecting Central and Eastern Europe. This small section of the Brda River has very unique character, due to the hydrological transformations during the nineteenth and twentieth centuries by human race. They were happening in the “adaptation of the Brda River to the inland waterways.” They were consisted in the construction of Brdyujście sluice. New hydrotechnical building created artificial water reservoir, which was used for recreational purposes, as the Regatta Track. Damming of the Brda River significantly changed water flow regime in this section. Flow has been slowed and has given nearly limnical nature to the estuary section of the Brda River. This is reflected in the transport of suspended material (total suspension) and the rate of the sedimentation in reservoir. Soundings of the bottom indicated varied thickness of the sediments. Subsequent hydrological changes in the analysed section of the Brda River, occurred at the time of closing the Brdyujście sluice and opening new inland waterway crossing to the Vistula River – Polish Czersko sluice. In this way, a significant part of the waterway (regatta track) was eliminated from the use. These changes are adversely affecting on functioning of the whole research part as an inland waterway. The dredged treatments serve not only providing proper conditions for a sporting event on the Regatta Track, but also should contribute to the improvement of navigation in this part of the Brda River. The research of the concentration of selected elements indicated the spatial variation in the rate of sediment accumulation processes. Based on available data, it is possible to propose dredged treatments as an element that enables the possibility of shipping on the Brda River section to remain at the same level.

The Lower Vistula River is a Polish part of inland waterways E40 that has a comparatively low waterway class (Ib – III; excluding Wloclawek Reservoir part – Va), and projects and works should be undertaken to improve the waterway class conditions. This also depends upon the ratification of the AGN agreement by Poland, which obliges the country to adapt the main waterways to at least the fourth class of navigability. A catalog of investment activities must contain environmental objectives due to the inclusion of Lower Vistula River in the Natura 2000 protected areas network. This research includes an analysis of the impact on the inland waterway transport of the investments included in the Vistula River Basin Management Plans (RBMP). These documents make it possible to rationally manage water resources (also in the waterway transport) and indicate actions aimed at maintaining them for future generations. Therefore, in line with the Water Framework Directive recommendations, all planned investments should have a minimal environmental impact. In the coming years, large-scale infrastructure investments are planned, which will allow the waterway transport conditions to be improved and the environmental goals of the Water Framework Directive (WFD) to be achieved.