Study of Continuous Simulation Supporting Multiple Design Criteria for Sustainable Drainage Systems

Traditional (piped) drainage systems are designed to drain quickly. It is therefore reasonable design a system assuming that it will be empty at the start of rainfall event. However, restoration full capacity in sustainable (SuDS) or low impact development dependent on slower processes (e.g., evapotranspiration, infiltration, consumption harvested rainwater). Current guidance often does not advise assumptions make regarding SuDS retention capacity. In addition, have control both runoff volumes and flow rates during routine extreme storm events. This presents two further interlinked challenges: first, identify relevant metrics define performance; and, second, appropriate performance criteria for design. Using rainwater harvesting as an example, argued continuous simulation supports calculation range metrics, properly accounting retention, empowering users set targets desired level protection. Six independent considered characterize response events, scatter pie plot introduced clear visual indicator across multiple targets. While current UK prioritizes flood risk mitigation aims provide protection up 1 100 year event, such stringent expectations may acting deterrent uptake, particularly domestic scale. Here, lower thresholds (for household SuDS) region 2 event 95% annual recommended.