CCWI2017: F136 'Analysis and Simulation of Drainage Capacity of Urban Pipe Network'

In the last decades the urban area of Leiria (Portugal) has spread quickly and the impervious surfaces increased significantly, mostly because of the type of pavements used (asphalt and Portuguese cobblestone) and the area occupied by buildings. One of the major problems is related to the recurrent floods in Leiria’s downtown during periods of higher rainfall intensity, which affect the economic activities, the environment and the residents’ lives. The urban area benefits from a large drainage network, but in some zones it has low performance, due to the degradation of the infrastructure and the successive located interventions occurred in the last decades (for network expansion and rehabilitation works). To minimize the flooding impacts in Leiria’s downtown, the municipality intends to build an underground pipeline (a length of 1.5 kilometres, with a 2.0 metres diameter and 0.2% slope) to convey the runoff by gravity from Leiria’s downtown to the river. This paper presents an integrated study of the urban catchment and the drainage network capacity using the Storm Water Management Model (SWMM). This study included the analysis of the solution for different rainfall intensities (corresponding to different return periods) to assess its performance and, when required, suggest additional recommendations.<br>