Using irrigation infrastructure is one of six potential options being flagged to address reduced regulated flow through the Barmah-Millewa reach of the Murray River.
The Barmah-Millewa reach is the narrow section of river that runs through the Barmah-Millewa Forest near Echuca and Deniliquin in the mid-Murray region. Capacity through the Barmah-Millewa reach has been reduced from 11,300 megalitres a day in the 1980s to 9200Ml a day today.
The Murray-Darling Basin Authority’s Andrew Reynolds said the options had been identified and scoped as part of a report for the Barmah-Millewa Feasibility Study, released on August 15, which was initiated at the request of Basin state governments.
“We have spent the past year investigating the cause of lower flows and changed river conditions in this important part of the Murray,” Mr Reynolds said.
“This work has meant looking at the whole river system to assess each option’s effectiveness and reliability, and its engineering and ecological viability.
“We have collected and analysed new information to fully understand the movement and impact of the sand slug, which has seen an estimated 20 million cubic metres of sand settle on the riverbed between the Yarrawonga Weir and Picnic Point.
“That’s about 13 Melbourne Cricket Grounds full of sand, caused largely by former land-use practices and gold mining in the rivers and creeks upstream.”
The six options being explored are:
- stabilising the banks to prevent further incursion of water into the Barmah-Millewa Forest;
- removing sand from key locations;
- changing the timing of water delivery to Lake Victoria-Tar-Ru to be better attuned to environmental watering events;
- using Goulburn-Murray Irrigation District infrastructure to deliver water downstream;
- using Murray Irrigation Limited system to deliver water through the Edward/Kolety-Wakool-Niemur river system;
- releasing water to the Murray River via the Murrumbidgee River through the Snowy Hydro scheme.
The options will be presented to governments in December 2022 for them to decide which options to investigate further or to proceed to a business case and formal community consultation.
The report is available on the MDBA website.