Sustainable Urban Stormwater Management: Hydrologic Performance of Low-Impact Drainage Design in an Urbanising Catchment

Abstract

Urbanisation increases impervious cover and accelerates the conveyance ofrainfall to drainage networks, raising peak flows and the risk of urbanflooding. This paper assesses the hydrologic performance of low-impactdevelopment (LID) and sustainable drainage systems (SuDS) relative toconventional drainage in an urbanising catchment. A rainfall-runoff modelwas developed for a representative catchment, and the runoff response wassimulated for conventional drainage and for a configuration incorporatingdistributed LID measures. The simulated hydrographs show that the LIDconfiguration attenuates the peak discharge and delays the time to peak while reducing total runoff volume. The discussion considers the design andplanning implications of distributed source-control measures, including theirintegration into urban layouts and the influence of catchment characteristicson performance. The study concludes that sustainable drainage offers a robust complement to conventional networks and that its benefits are maximised when source-control measures are embedded within the planning of urban development rather than added retrospectively. KEYWORDS: Stormwater management, Low-impact development,Sustainable drainage systems, Runoff hydrograph, Peak attenuation, Urbanflooding, Catchment hydrology.