Urban stormwater runoff and pressure on the sewerage system in Pécs, Southwest-Hungary

Pecs is a city with rugged topography on the foothills of the Mecsek Mountains, Southwest-Hungary. As a consequence of uncontrolled city development in an environmentally sensitive area, the sewerage system is unable to cope with the additional pressure and overflow following torrential rainfalls and rapid stormwater runoff. The main objective of our study is to investigate the problems involved by extra rainwater released illegally into the sewerage network in the city. Special attention is paid to the analysis of the topographic factor contributing to enhanced runoff using Digital Elevation Model. A neighbourhood with particularly diverse topography, the Magyarurog Valley on the Mecsek foothills, where blocked stormwater drainage is a most serious problem, is selected for a representative case study. Residential buildings in different topographic positions, as potential sources of extra water inflow into the network, are referred into four classes of probable input into the system. The findings of the survey can be used in the design of a future stormwater runoff monitoring system. Controlling illegal release into the sewerage system is an important task since it could cause millions of Euros of losses to the community-owned waterworks. Our study presents a typical example how private preferences confront with public interest in an urban landscape.