Some of the Murray Darling Basin’s best managed waterways would be damaged by water infrastructure projects that benefit major corporate irrigators, according to a new report by water consultants Slattery & Johnson and think tank The Australia Institute.

The Yanco Creek System, which links the Murrumbidgee and the Murray rivers, is declared a “jewel” of the Basin by local water managers but has been labelled as “effluent creeks” by the Murray Darling Basin Authority (MDBA) as it pushes ahead with its ‘supply measure’ projects.

“The fact that water agencies refer to the Yanco Creek System as ‘effluent creeks’ gives an idea of what they are planning for this region,” said Maryanne Slattery, Director of Slattery & Johnson.

“The Yanco creek system is one of the best managed parts of the Basin. It is the ideal of a healthy, working creek system, but this is at risk due to supply measure projects caused by the 2018 amendment to the Basin Plan.

“It is doubtful these projects would save any water at all as the ‘transmission losses’ they purport to save are actually natural and necessary parts of the water cycle.

“Even the water agencies tasked with implementing these projects have said that benefits of the projects have been ‘overstated’ and that any ‘savings are largely taken up delivering environmental flows back into the system they were saved from’.

“These infrastructure projects will increase extractions for irrigation, above and beyond the intended savings, because they will increase ‘supplementary flow’ in the Murrumbidgee.

“Supplementary flows can be used by licence holders, but historically have not been used due to a lack of infrastructure. Government-subsidised new dams have been built to use supplementary flows and changes to the way they are licenced will also increase their extraction.”

“Beyond the damage that these supply measure projects would cause, they are probably unlawful. The Basin Plan and the Water Act are clear in how these projects need to be measured and modelled, but these requirements are not met in the Yanco Creek System,” said Roderick Campbell, Research Director at The Australia Institute.

“The Yanco Creek Supply measures projects would damage this creek system, communities and leave taxpayers exposed to legal challenge. If governments persist with these projects they will be leaving communities and taxpayers up the proverbial ‘effluent’ creek, without a paddle.”