Poster Presentation Australian Freshwater Sciences Society Conference 2024

A collaborative approach to managing stormwater during urban development. (#107)

Angus Macdonald 1 , Ross Thompson 1 , Isobel Walcott 1 , Jill Bartlett 1
  1. University of Canberra, Bruce, ACT, Australia

Canberra is the largest city in the Murray Darling Basin and is expanding rapidly, with urban centres rapidly encroaching on river corridors. The suburbs of Stathnairn and Macnamara are being built on the western edge of Canberra, immediately adjacent to the Murrumbidgee River.  The ACT Government (in partnership with the developers, Riverview Group) has sought to protect the river from construction and urban runoff, through a series of novel stormwater management interventions. The Centre for Applied Water Science at the University of Canberra has been monitoring water quality both on the construction sites of the new suburbs and in the adjacent Murrumbidgee River Conservation corridor to assess the impact of water releases from the suburbs during construction.  Stormwater has been passed through a series of stormwater sediment retention points and subject to treatment with alum. A high efficiency sediment basin was used in Stage 1 but suffered from failure due to extreme rainfall events. In Stage 2 a combination of traditional retention basins with later conversion to wetlands was applied. One of the main outcomes from the project was recognising that close collaboration between the water monitoring program and stormwater engineers allowed more agile and innovative responses to issues, adopting an adaptive management mindset. Research has shown that exceeding the minimum guidelines required for sediment control for construction sites has enabled greater protection for the corridor, particularly with the inclusion of multiple changed sediment ponds, contouring of sites to reduce velocity and a greater understanding of position selection for sediment ponds. The project indicates the value of collaboration of industry, government and private stakeholders in urban stormwater management.