Blackwater update 2

Wednesday 4 January, 2017
Blackwater in the Goulburn River has moved past McCoy’s Bridge and should reach the Murray River in a couple of days.

  • Dissolved oxygen levels dropped at McCoy’s Bridge to critically low levels but have started to recover. The dissolved oxygen levels will further improve as the environmental water released from Goulburn Weir (up to 3000ML/day) since Sunday mixes with the blackwater.
  • Although low dissolved oxygen levels were recoreded at McCoy’s Bridge fish deaths similar to those that occurred around Shepparton have not been observed in the McCoy’s Bridge area to date.
  • The amount of environmental water that can be delivered is limited by river operations and the need to share channel and river capacity with water users such as irrigators and town supplies.
  • The blackwater is not expected to cause fish deaths when it flows into the Murray as the Murray flows are stronger and the blackwater has been diluted. However, there maybe some discolouration and a change in water quality.
  • People may continue to see dead fish in some sections of the Goulburn River as they move downstream from the Shepparton area. Poor water quality and higher temperatures later this week may result in further deaths.
  • The blackwater is not due to an environmental water delivery; it is a result of debris-rich run-off from tributaries including Castle, Pranjip and Seven creeks and the Broken River that entered the Goulburn River after more than 100mm of rain fell across parts of the catchment on December 29.
  • Monitoring native fish tagged as part of a program we’re conducting with Arthur Rylah Institute, Fisheries Victoria, the Commonwealth Environmental Water Holder, MDBA and other agencies will help determine any potential long-term impacts of this event.
  • Goulburn Broken CMA is also considering an environmental water delivery along the lower Goulburn River early autumn to encourage yellow belly to migrate from the Murray River into the Goulburn River.
  • The community is encouraged to report fish deaths to the EPA on 1300 372 842.