Short Virtual Presentation & Digital Poster 10th Australian Stream Management Conference 2021

Post-fire response in the Warragamba drinking water catchment. (#33)

Rhiannon Hughes 1 , Rebecca Mabbott 1
  1. Soil Conservation Service, Parramatta, NSW, Australia
  • The Warragamba Catchment, responsible for 80% of Sydney's drinking raw water supply, had 300,000 ha of land impacted by the 2019/2020 Black Summer bushfires. This scale of impact in a drinking water catchment was unprecedented in Australia. In response, the Soil Conservation Service (SCS) was engaged by WaterNSW to investigate the severity of damage to the catchment, risk to drinking water supply and feasibility of mitigating risk to water supply using erosion control methods.
  • SCS integrated analysis of fire extent and severity model (FESM), erosion risk models, gully risk models, River Styles, proximity to water storage/offtake, distribution of vegetation buffers and on-ground inspection to identify areas posing the highest risk to water supply from sediment and greatest feasibility for on-ground erosion mitigation works. SCS conducted a literature review to determine the most suitable on-ground erosion mitigation methods for the wilderness and world heritage area.
  • The project provided greater insight into the preparedness of industries to bushfire response, the feasibility of intervening in post-fire recovery at large scales particularly in wilderness and world heritage areas and knowledge gaps in post-fire catchment response.
  • This investigation will inform future bush fire response in water supply catchments. SCSs review of current post-fire erosion control methods has identified where efficiencies can be gained and numerous knowledge gaps on the suitability and environmental impact of post-fire erosion control methods being used in Australia.
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