Flood mitigation benefits of rainwater tanks

Peak flood mitigation can be achieved through on-site detention methods including through household rainwater tanks. The purpose of this research is to assess flood mitigation benefits of household rainwater tanks. Specifically in terms of peak flood volumes reduction and other associated environmental, social and economic benefits. The catchment in study is Sutton Lakes within Knox City Council where there are several storm water related issues, including the traditional inadequate piped storm water network and various water quality concerns within the lake system. Through various flooding and water quality computer modelling a detailed analysis was performed in order to quantify these benefits within the project area. During the 5 year ARI storm there was a 12.6% reduction in pipe flows from the outlet of the system, which correlates to a possible drop in pipe dimensions in the catchment. This reduction also includes a 43% in overland flows which cause building inundations.