Skip links and keyboard navigation

Removal of barrier

Removal of barrier

Removal of old Norco Weir on the Richmond River, Casino, New South Wales Photo by Matthew Gordos

Disclaimer: In addition to the standard disclaimer located at the bottom of the page, please note the Fishways (biopassage structures) disclaimer.


The removal of artificial instream barriers can be an option for restoring connectivity for fish and other aquatic fauna. It involves reinstating the natural open channel allowing all species and size classes of fish and other aquatic fauna to move at all flows. Removal is becoming increasingly considered as old structures become redundant[1].

Barrier removal is not a simple concept or task. It is vital to have broad stakeholder involvement including social, economic, cultural and heritage representation.

Detailed assessments are required to understand potential impacts of removal e.g. instream barriers may hold back large amounts of impounded sediment and contaminants, which need to be evaluated and planned for before barrier removal and some natural barriers are also important for maintaining isolated populations (i.e. protection from predators and genetic isolation). Artificial instream barriers can also create important refuge habitats in areas such as the Murray Darling Basin, which may become increasingly significant as surface flow reductions continue[2].


  1. ^ O'Connor, J, Stuart, I, Jones, M & Arthur Rylah Institute for Environmental Research (2017), Guidelines for the design, approval and construction of fishways. [online] Available at: [Accessed 25 February 2021].
  2. ^ Robson, BJ, National Climate Change Adaptation Research Facility (Australia) & Murdoch University (2013), Novel methods for managing freshwater refuges against climate change in southern Australia. [online] Available at: [Accessed 19 February 2021].

Last updated: 10 May 2021

This page should be cited as:

Department of Environment and Science, Queensland (2021) Removal of barrier, WetlandInfo website, accessed 13 April 2023. Available at:

Queensland Government
WetlandInfo   —   Department of Environment and Science