This diploma thesis presents the topic of urban drainage systems. The first theoretical part contains methods and options for urban drainage systems, stormwater management, blue-green infrastructure (BGI) in urban areas and introduction of numerical modelling of sewerage systems. The application of modelling platforms is further described in the feasibility study in the practical part of this thesis. By using the simulation model, the study assesses the hydraulic reliability of the drainage system in the city of Jedovnice in the Czech Republic, identifies hydraulic issues and their causes on the urban drainage system. The second part of the study assesses extra-urban stormwater inflow from fields around the city caused by heavy rainfalls, which causes local flooding in the urban area. The identification as well as proposed solutions and capital expenditures, their comparison and recommendation of the optimal solution are included in the study.