Follow UsFollow UsFollow Us
Home »

Great Darling Anabranch - return of an ephemeral system

  Great Darling Anabranch - return of an ephemeral system
 

Full Title

Darling Anabranch Adaptive Management and Monitoring Plan

Contact Person 

Deborah Bogenhuber

Funding Body

NSW Office of Environment and Heritage

Duration

Initially 2010 to 2013 (designed as a ten year monitoring program)

Summary

The Great Darling Anabranch, in south-west New South Wales, is an ancestral path of the Lower Darling River, approximately 460 km long. It is a naturally ephemeral system but was managed as a permanent water storage supply for landholders, until early this century. Collaboration between landholders, managers, government and scientists over many years resulted in the construction of a pipeline in 2007 to secure water supply and return the Darling Anabranch to an ephemeral system. The Darling Anabranch Adaptive Management Monitoring Program (DAAMMP) was established to monitor ecological responses to the changed hydrology. Monitoring began in 2010, funded by NSW Office of Environment and Heritage, and the program is expected to continue until 2020.

The DAAMMP includes annual ‘condition monitoring' of understorey vegetation communities and riparian tree health, and ‘intervention monitoring' of fish, frog and waterbird communities during managed and natural flows. In September 2010 an environmental flow was released down the Anabranch, which was superseded by an overbank flood by mid-October. The Anabranch flowed its full length for the first time in over 10 years. 

Three years on and a picture is emerging of the response of the following to the new, more natural ebb and flow of water along the Darling Anabranch:

  • Geomorphology
  • Water quality
  • Fish community
  • Yabby populations
  • Frog community
  • Waterbird community
  • Understorey vegetation community
  • Lignum
  • Riparian tree community
  • Natural organic matter loading
  • Distribution of Cumbungi 

One key finding from the three years of data: the return of the Darling Anabranch to an ephemeral system increased fish diversity from six species in 2002 (during regulation), to 13 species throughout the 2010–11 and 2011–12 overbank flows. The Darling Anabranch has been identified as an important habitat for the viability and recruitment success of native fish species in the Murray-Darling Basin. The successful management of the Darling Anabranch as an ephemeral system may be crucial to supporting a diverse and abundant Murray-Darling Basin native fish community.

Smelt sampled in large numbers during the 2013 environmental flow along the Darling Anabranch.