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

Enhancing floodplain connectivity, first steps towards habitat restoration for threatened species (#84)

Peter Sandercock 1 , Simon Treadwell 2 , Joe Greet 3 , Lisa Stuart 4 , Dan Harley 4
  1. Jacobs Group Australia, Bendigo, VIC, Australia
  2. Jacobs Group Australia, Melbourne, VIC, Australia
  3. University of Melbourne, Melbourne, VIC, Australia
  4. Zoos Victoria, Melbourne, VIC, Australia

Zoos Victoria have identified several waterways in the Coranderrk Bushland Reserve and Macclesfield Creek as areas for ecological restoration to provide habitat for the potential release of two critically endangered species – the Helmeted Honeyeater and Lowland Leadbeater’s Possum.  In the past 100 years the floodplains of these waterways and their hydrological regime have been extensively modified.  The broad objective of the project was to identify what works are required to restore appropriate flow regimes to facilitate the recovery of critical habitat for these threatened species. We analysed digital terrain models and built hydraulic models to understand the current hydrological condition of these floodplains.  These models were integrated with the outcomes of vegetation surveys, and a series of modelled scenarios were developed to assess the effectiveness of a range of structural measures in enhancing floodplain connectivity.  In some areas, temporary structures have been built that block drainage channels and these have been found to enhance watering of floodplain areas benefiting floodplain vegetation.  Watering of floodplains using leaky pipes has also been trialled. For Coranderrk Reserve, we learnt that there may be opportunities to manage water from an existing water storage (Lake Coranderrk) and deliver a seasonal watering regime to downstream floodplain areas.  It is also recommended that coir logs are installed in channels to create shallow ponding and enhance floodplain engagement and benefits to vegetation from flow releases.  For Macclesfield Creek, trial structures were shown to be effective at reducing channel capacity and increasing the frequency of floodplain inundation.

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