Conference Agenda

This paper describes the outcome of a research project that investigated the stormwater quality and quantity implications of transforming detention ponds into multi-purpose facilities in Cape Town. Increasing urbanisation has led to a predominance of impervious surfaces causing increased stormwater runoff, decreased groundwater recharge, and lowered water quality in the receiving waters. Sustainable Drainage Systems (SuDS), such as stormwater detention ponds, can mitigate impacts of urbanisation and climate change, achieve environmental benefits, and provide recreation and social amenities. However, to fully realise their potential, a paradigm shift is required in the city’s approach to stormwater management. This study focused on a former detention pond in Mitchell’s Plain that has been retrofitted for extended detention and infiltration. Stormwater treatment efficiency and infiltration potential were evaluated for water quality and quantity using a mixed methods research philosophy that combined field experiments, laboratory investigations, and computational hydraulic simulations using the PCSWMM software to enable a long-term assessment of the likely performance of the retrofits. The water quality and quantity results demonstrated that retrofitting the School Pond with the additional SuDS components enhanced its multifunctionality, improving water quality and reducing stormwater outflow volumes and thus contributing to more sustainable stormwater management