Quantification of the hydraulic dimension of stormwater management system resilience to flooding

Climate change, increasing urbanisation and a growing concern over existing stormwater management systems (SWMSs) has resulted in the development of various approaches to improve urban resilience to flooding and the performance of SWMSs. However, previous studies have focused on urban resilience and the hydraulic reliability of urban drainage systems, without considering all dimensions of a SWMS as the main urban flood control infrastructure. This paper presents an approach to quantify the resilience of the hydraulic dimension of primary SWMSs to flooding. Resilience was quantified based on the Hydraulic Performance Capacity (HPC), a new metric developed to represent the functionality of a SWMS over time using the temporal hydraulic characteristics across a catchment. The effect of network properties, catchment characteristics, and design storm events can be assessed through this approach based on the outputs of standard One Dimensional (1D) hydraulic modelling. The approach was applied to a case study urban catchment and was able to demonstrate the effect of different storm events and pipe material properties on resilience, robustness, and recovery. This framework can be used by decision makers to benchmark SWMS network resilience, optimise network capacity for design, and assess methods for reducing flood hazard in urban catchments.