Optimum numbering and sizing of infiltration-based water sensitive urban design technologies in South Australia

Abstract

The existing drainage systems consider storm water as a waste product and its main focus is on collecting the runoff from urban catchments as quickly as possible and discharging it into the nearby outlets. These traditional drainage systems cannot consider important utilisation of storm water. Therefore, a decentralised storm water management option, known as, Water Sensitive Urban Design (WSUD) technologies, can be implemented in the urban catchments to minimise the negative hydrological impacts due to urbanisation. Hydraulic designs of three different types of infiltration-based WSUD technologies (leaky wells, soakaways and infiltration trenches) were designed for South Australian contexts. Modelling equations to estimate optimum numbering of infiltration systems were developed using SPSS and six different independent variables, such as soil hydraulic conductivity, size of the device, average recurrence interval of rainfall events, critical storm duration, rainfall intensity and roof size, were considered. The developed modelling equations were statistically significant and were applied in the real-case scenarios of South Australian catchments.