Identifying representative stormwater quality events for pollution load prediction in planning and modelling contexts

Currently, applied solutions for better stormwater management systems often target both water quantity and quality related issues. However, while frameworks for assessing quantity performance have been
developed and applied (using e.g. exceedance return period as decision parameter), there is still a lack of consensus on the best evaluation approach for water quality performance. This study aims at simplifying the evaluation of pollution removal performance of stormwater control solutions in the planning phase by exploring the possibility of identifying a selection of Characteristic Rain Events (CRE). Each CRE will be associated with a corresponding mass-volume (MV) curve for Total Suspended Solids (TSS) loads. This relationship is identified by using a clustering approach. The use of CRE can simplify the planning process with respect to water quantity and quality aspects, provide an additional aid in modelling for decision making, and it can thus speed up collaboration between stakeholders in multi-objective, interdisciplinary planning situations.