Increasing urbanization results in a significant increase in areas with impermeable surfaces and, consequently, an increased risk of flash floods on the one hand, and on the other hand, limiting the functions of the ecosystem. As solutions based on nature, rain gardens can be a key element of urban space in creating cities resistant to climate change, increasing biodiversity, or preventing the urban heat island phenomenon. Therefore, they can be an element of rainwater management supporting the restoration of ecosystem functions in cities. The project aims to identify individual processes occurring in rain gardens that may lead to the removal or accumulation of pollutants present in rainwater in the city. Currently, rain gardens that are part of the blue-green infrastructure (technologies based on nature) are more and more often used in cities to manage rainwater and at the same time to adapt cities to climate change. Due to the large number of pollutants identified in rainwater, the question arises whether rain gardens are capable of removing these pollutants and, if so, in what processes. Nevertheless, the impact of blue-green infrastructure, including rain gardens in cities, and Poland in particular, is not the subject of much scientific research. The implementation of the rain gardens in Gdańsk started in 2018, so these systems are relatively new and are not subject to monitoring of the quality of rainwater and surface runoff. The aim of the activities will be analysis the spatial distribution of pollutants in individual elements of the rain garden. The quality of rainwater will be analyzed in terms of basic parameters, i.e. pH, electrolytic conductivity, chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), and additionally caffeine (as an indicator of the presence of domestic wastewater) and Chlorides (as an indicator of the presence of municipal wastewater (e.g. from streets) and industrial wastewater). The planned scope of research in the project will allow for the identification of pollutants depending on the nature of the catchment area, what is more, it will be possible to analyze the individual processes of removing these pollutants in individual elements of the rain garden. Consequently, it may improve the way they are designed and operated.