Nationals charge in with plan for Big Buffalo

A new dam and hydro system in Victoria’s northeast could bolster water security in the Murray-Darling Basin, the state Coalition says.

Nationals deputy leader and Coalition water spokeswoman Steph Ryan at Lake Buffalo near Myrtleford in northeast Victoria. Picture: Simon Dallinger

A massive new dam and hydro system in Victoria’s northeast could bolster water security in the Murray-Darling Basin by providing enough storage capacity to fill 400,000 Olympic swimming pools, as well as generating renewable energy, the Victorian Coalition says.

Amid a refusal by the Andrews government to even consider building dams, Victorian ­Coalition water spokeswoman Steph Ryan is calling on her federal counterparts to investigate an expansion of Lake Buffalo, near Myrtleford, as part of the Murray-Darling Basin tri-state agreement between Victoria, NSW and South Australia.

The “Big Buffalo” project would see the lake ­expanded from its current 23.9GL to 1000GL, making it the biggest dam built in Australia in more than a quarter of a century.

A pipeline with capacity for hydro-electricity generation would then transport the water to Lake Nillahcootie, between Mansfield and Benalla — under a design Ms Ryan says has previously been investigated by Goulburn-Murray Water.

The Lake Nillahcootie pipeline would see the water enter the Murray River upstream of Echuca via the Broken and Goulburn ­rivers — rather than flowing down the Buffalo and Ovens rivers to enter the Murray near Bundalong — avoiding the Barmah Choke, where capacity constraints have seen increased environmental water flows cause flooding and erosion of the Murray’s banks.

Ms Ryan said the Morrison government’s National Water Grid Authority, established on October 1, should evaluate the potential of Big Buffalo to secure water supplies for farmers and the environment.

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The agency has been asked to examine “how large-scale water diversions, including new dams and weirs, could be established to deliver reliable and cost-effective water to farmers and regional communities”, with $100m allocated for initial investigatory work. Ms Ryan said Big Buffalo could also help offset losses from evaporation further down the Murray-Darling, such as from Lake Victoria in western NSW, which provides South Australia’s largest off-river storage under the tri-state agreement and lost 130GL to evaporation last year.

“What we’re saying is, build a way more efficient storage at Buffalo as a tri-state agreement, where we give South Australia storage capacity in Buffalo in return for reducing reliance and saving those evaporative losses,” the Nationals deputy leader said.

She said the idea of ­expanding Lake Buffalo had previously been dismissed because it was contrary to limits on the amount of water that could be ­diverted from the Murray-Darling Basin. “But we’re not proposing to create new irrigation licences, we’re proposing to basically use those savings, to make a more ­secure entitlement,” Ms Ryan said. “So in more years irrigators will get a higher percentage of their water allocations than they currently do.”

Average monthly water allocation prices have increased from approximately $230 a megalitre in July last year to almost $800 in the Murray system and $530 in the Goulburn system.

Lake Buffalo was intended to be the first stage of a much larger project when it was completed in 1965, meaning Goulburn-Murray Water already owns the land required for an expansion.

In 2014, Goulburn-Murray Water estimated the dam enlargement would cost $600m.

A costing of the hydro pipeline proposal is yet to be done, but the interstate power transmission line could provide a relatively direct route through steep, remote country.

“It would be a big, nation-building kind of stuff. It’s not a little project,” Ms Ryan said. “I think it should at least be investigated, and the environment is right at the moment when you’ve got the federal government putting all of this money on the table and saying, ‘We want big projects’.”

A 1000GL Big Buffalo dam would become the 21st largest constructed reservoir in Australia.

The nation’s most recently built larger dam is western Tasmania’s 1065GL Crotty Dam, completed in 1991.