Stormwater runoff management in Sandomierz, as an example of medium-sized European city, using SCALGO Live

European cities face urban, demographic and climate challenges. According to forecasts, annual extreme phenomena will intensify - including torrential rains. Comprehensive solutions (also those based on nature), climate adaptation strategies, runoff management, incorporation of new design (e.g. sponge cities) are urgently required in order to strengthen urban resilience and to minimise the effects of extreme weather events (droughts, floods or heat islands). The aim of the research was to develop a methodology for activating selected elements of blue-green infrastructure within areas of natural and cultural protection as an adaptive tool of urban planning. Modelling of infiltration possibilities, programmed with SCALGO Live Poland software, was performed as a case study based on a research city - Sandomierz (in Poland). Selected parameters (stormwater surface runoff, chosen runoff areas, land cover) are strongly correlated with urban indicators relating to the vegetation coverage (biologically active area - BAA). Results pointed out urban units, which BAA is lower than 25% (e.g. Old Town Square, courtyards of tenement houses). Modelling was carried out for these units by concentrating on the undeveloped area for which the BAA was increased. The enhancement assumed values in the range of 41-45%. In analysed cases, an improvement (decrease) in runoff volume was obtained, even by 8.69%. Simultaneously, infiltration increased by 19.61%, calculated over entire runoff area. Implementation of solutions based on these results, in the form of appropriate planning provisions, can raise the quality of environment (e.g. improving water infiltration) and life (e.g. more effective air cooling on hot nights).