Oral Presentation 9th Australian Stream Management Conference 2018

It’s a good news story! Tracking geomorphic recovery of rivers in eastern New South Wales as part of process-based river management (#98)

Kirstie Fryirs 1 , Gary Brierley 2 , Fergus Hancock 3 , Tim Cohen 4 , Andrew Brooks 5 , Ivars Reinfelds 6 , Nick Cook 3 , Allan Raine 3
  1. Macquarie University, North Ryde, NSW, Australia
  2. University of Auckland, Auckland, New Zealand
  3. NSW Department of Industry, Crown Lands and Water Division, Newcastle, NSW, Australia
  4. University of Wollongong, Wollongong, NSW, Australia
  5. Griffith University, Nathan, Queensland, Australia
  6. NSW Department of Industry, Crown Lands and Water Division, Wollongong, NSW, Australia

Across much of south eastern Australia, clearance of forests and riparian vegetation, and removal of wood from channels in the 19th and 20th centuries induced widespread geomorphic impacts. However, since the 1970s there has been a noticeable and significant shift in the geomorphic condition of many rivers. This reflects increases in groundcover and re-establishment of woody vegetation within riparian and in-channel zones associated with a reduction in land-use pressures and improved farming practices on the one hand, and adoption of recovery enhancement approaches to river conservation and rehabilitation by management authorities on the other. Following a brief review of river change in eastern NSW since European settlement, we outline an approach to identify and measure key geomorphic indicators of river recovery for different river types. We use case studies to demonstrate examples of geomorphic river recovery and the ‘things to look out for’ when assessing geomorphic river recovery. For example, the formation and stabilisation of benches, pool scour and re-establishment, reformation of swamps in channelised systems, and the reorganisation of bed materials into well-defined low flow channels are key indicators of geomorphic river recovery for some rivers. We present how this approach to monitoring and tracking changes in condition can be used to identify when geomorphic recovery is occurring so that decision-support frameworks can determine whether river management is required, where, when and how much to intervene to enhance river recovery and when to opt-out of management because the system requires little (or no) intervention. Broader implications of this ‘good news story’ are discussed.

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