The main aim of the work detailed here was to identify the level and composition of selected atmospheric pollutants supplied mainly with precipitation to the urbanized Różany Strumień catchment in Poznań, Poland; and to determine their impact on the chemical composition of water at subsequent stages of its circulation. The research was conducted in the hydrological years 2016-2020 as part of the Integrated Monitoring of the Natural Environment in Poland (ZMŚP) program, using the infrastructure of the ZMŚP’s "Poznań-Morasko" Base Station – of Adam Mickiewicz University in Poznań – the first such Base Station to be located within the boundaries of a large urban agglomeration. A key finding concerned a positive ion balance among nutrients supplied as a result of human activity (e.g. through fertiliser use) – involving NO3-, NH4+ and K+. Remaining chemical components (denudation ions) present in the waters circulating in the catchment are in turn characterised by a negative balance.