The Murray-Darling Basin Authority placed an order for 50 Gl to be delivered from the Goulburn River this month to meet downstream Murray River demand and maintain water in Lake Victoria, a key storage for South Australia.
Recently, the Victorian Government announced inter-valley trades would be limited to 50 Gl a month from December to April to help reduce environmental damage to the lower Goulburn River caused by high inter-valley trades during 2017-18 and 2018-19.
The MDBA order will see flows in the Goulburn River increase from the current IVT rate of 1300 Ml/day to an average of 1700 Ml/day.
Goulburn Broken Catchment Management Authority chief executive officer Chris Norman said the preferred flow would be 1000 Ml/day to give bank vegetation a chance to grow and provide habitat for bugs and small fish.
“Higher flows in the Goulburn at this time of the year, when you’d expect flows to be low, cause environmental damage such as erosion,” he said.
“We’ve used water for the environment in spring for the past five years to help spread the seeds and plants that help stabilise the banks and provide shelter for native fish and wildlife.
“Monitoring showed water for the environment was making a difference and that the banks were starting to recover from the last drought and floods.”
Goulburn Broken CMA has asked for the IVT flows to be delivered at a variable rate, to limit environmental damage to the Goulburn River.
“Unfortunately the record high IVT deliveries over the past two years during summer and early autumn have undone much of the good work we were starting to see,” Mr Norman said.
“They’ve caused erosion of the lower bank and loss of bank-stabilising vegetation, which means the banks are now even more vulnerable to high unseasonal flows.
“That’s why we’d requested that if this water had to be delivered at this time of the year our preferred delivery option was after cod opening, which provides huge economic and recreational benefits to this region.
“And, rather than delivering it at a constant rate over a long period of time, which causes erosion and drowns lower bank vegetation, we’ve recommended that it’s delivered at a variable rate with a short higher pulse of water in mid-December.”
Flows in the lower Goulburn River (downstream of Goulburn Weir) will remain about 1300 Ml/day during the next few days before a pulse of about 3000 Ml/day is delivered around Tuesday, December 17.
The effects of IVT and unseasonally high flows on the banks will continue to be monitored by Goulburn Broken CMA.
For more information on interim changes to Goulburn River operations visit: