Designing a pond and evaluating its impact upon storm-water quality and flow: A case study in rural Australia

Storm-water management is a common concern in rural catchments where development-related growth causes increases of storm-water flows. Greater magnitude and frequency of storm-water create greater challenges for mitigating storm-water damage and improving water quality. The concept of Blue-Green Infrastructure (BGI) as a solution incorporates a wide range of applicable components with the aim of minimizing the effect of catchment development on flow regimes without changing the watershed morphology. BGI components manage storm-water by decreasing impermeable cover and expanding natural and semi-natural systems to store water or recharge and filter storm-water into the ground. In this paper, guidelines for designing a pond as a component of BGI are provided and, configuration and size of the pond are determined. Moreover, the impacts of the designed pond on storm-water peak flow and quality are assessed for the Tarwin catchment, State of Victoria, Australia. The results indicate that the introduction of the pond would have reduced outfall inflow by 94 % and would have achieved the reduction of 88.3, 75.5 and 50.7 % for total suspended solids, total phosphorus, and total nitrogen respectively, during the extreme weather event in June 2012.