Stormwater harvesting and water sensitive urban design detention: a compatibility analysis

Abstract

Harvesting stormwater from urban catchments provides a supplementary water resource and, due to the physical abstraction of polluted water, also leads to environmental benefits. These benefits include the reduction of frequent ecosystem disturbance during small storms and less waterway erosion; hydrological impacts which are currently addressed by WSUD guidelines for stormwater detention. Although WSUD detention and stormwater harvesting share the same store-release behaviour, they have a very different underlying basis to their design and operation. This paper explores the level of compatibility between these two systems and hence the potential for their integration. It was found by water balance analysis that the harvesting storage required to maximise most yields are similar to the recommended storage volume for detention. This analysis was performed for a temperate-climate location in South East Queensland under historically low rainfalls. Environmental benefits associated with runoff quantity and pollutant load reductions are highest when the capture storage is rapidly emptied after storms.