Managing floods using sustainable infrastructure, a case study

Floods occur in the Al Rawdah neighbourhood in Irbid city due mainly to excessive precipitation, the abundance of impervious surfaces, and shortages in the current drainage capacity. Global warming and urbanisation have also increased flood risks and severity. Therefore, green infrastructure (GI) was proposed to alleviate flood risks and to benefit from heavy stormwater events. The current study analysed the urban floods in the study area and compared the hydraulic performance of the existing network, the grey network, and the GI flood management systems. The ability of these systems in managing runoff, inflow, flooding, and storage capacity in different storm scenarios was evaluated. Several software, including Storm and Sanitary Analysis and Global Mapper, were used. Results show that the GI system significantly outperforms both the existing and grey networks. In terms of mitigation of flooding, runoff reduction, and storage capacity, the green system was more effective than the grey systems, particularly during severe storms with extended return periods. The green system was more resilient to flooding due to its capacity to store and delay runoff flow. It also performed effectively in capturing runoff. Economically, the green system is more cost-effective to construct and maintain, with a higher benefit-cost ratio.