ABSTRACT
A growing number of people around the world and their migration to cities is changing the zoning of the areas and enforces the need for their expansion. Intensive development of urban areas is a challenge for the designed, in particular for the existing rainwater drainage and the combined sewerage systems. Urbanization, which causes changes in the way of the catchment usage, affecting the growth of the sealing of the area surface, also contributes to intensify the outflow of rainwater. The result of this, commonly found in urban areas phenomenon, is the dissipation of the cubic reserves of the existing channels, flooding the sewage facilities, the occurrence of so-called “urban flooding” and flooding events in urban streams. The article presents the results of hydrodynamic simulations performed for the actual urban catchment. In the research, conducted on the SWMM software, the impact of expansion of the city and the way of the rainwaters usage on its area on the existing drainage system was analysed.
