The overall aim of the EuroCat Project is to develop a quantifiable framework of analysis for improved planning and management of catchments by analyzing the response of coastal zones of the North, Mediterranean and Baltic Sea, to changes in fluxes of nutrients, organic and inorganic xenobiotic compounds from the European rivers and their catchments (Axios, Elbe, Humber, Po, Rhine and Vistula). These changes are a consequence of introduction a new legal regulations, schemes and socio-economic conditions in the areas of countries where these catchments are located. The scale of these changes is also dependent on biogeochemical and physical properties of the catchment and they are carried from the local to global scale. The specific goal of the VisCat program is to create a system which will be used to evaluate the environmental impacts on the Vistula river catchment and the Baltic Sea due to the change from the central economy to the market economy in Eastern and Central Europe (VisCat). The primary issue of this program is also to assess the influence of the run-off reservoir in Wloclawek (Wloclawek dam), sewage-treatment plant in Torun and Vistula river?s tributaries on reduction of sediments, plankton and other pollutants in the Vistula river. Next the impact of these local changes on the global state will be studied. Another aspect of this study area within the EuroCat-VisCat program will be estimation of socio-economic changes such as: adapting the Polish law concerning management of water resources, state, regional and local programs of activity in this area and human influence on the water and ecosystem of the Vistula catchment and the Baltic coastal zone (tourism, agriculture, industry etc.) related to directives of the European Union. Next all these results will be referred to the global situation in the whole of Europe to make a prognosis of the state and behaviour of river catchments and coastal zones in the future.