The stormwater drainage system is an infrastructure facility that accumulates the rainwater, protecting the urban areas from flooding. An important parameter for stormwater drainage systems in urban areas is the size, shape and type of the catchment area. According to current practice the catchment area can be determined by several methods: classical methods where the catchment area can be defined using a roof symmetry by links or by distributing it in equal parts at all nodal points of the hydraulic model and modern methods in which the definition of the catchment area is made by taking into account additional parameters such as the slope of the terrain, the position of node points, the distance of the connection points to the future sewage, the size of the catchment area, etc.

Subject of this hydraulic analysis is to apply the classical and modern methods for defining the catchment area in order to show the advantages and disadvantages of the methods with a further comparison and recommendations for designing the stormwater drainage system.