The NSW Government has made revisions to a key water-saving proposal under the Murray-Darling Basin Plan, after federal authorities raised environmental concerns.
The Menindee Lakes in far-west NSW are a crucial component of the Plan, storing floodwaters that travel down the Darling River and controlling the release of flows downstream into the Murray.
The Department of Industry is planning to re-configure the lake system, in part to stop water flowing freely from Lake Menindee into Lake Cawndilla, keeping Cawndilla dry more often.
It is designed to reduce evaporation, saving water that might otherwise be bought back from irrigators, and is one of 36 water-saving proposals submitted by governments under the Murray-Darling Basin Authority’s Sustainable Diversion Limit adjustment program.
But a Murray-Darling Basin Authority (MDBA) analysis of the project said the NSW Government did not submit an environmental impact statement for the plan, and raised questions about its effect on local ecology.
The Menindee Lakes are a crucial part of the Murray-Darling Basin Plan, regulating flows downstream, and storing floodwater from upstream. (Flickr: NASA Earth Observatory)
The analysis, provided to the ABC by Nick Xenophon Team senator Rex Patrick, identified several gaps in the information provided to the MDBA in the government’s formal proposal.
It said the government should have made reference to “emerging research … that suggests the area is of Basin-scale significance in supporting self-sustaining populations of golden perch.”
“This is the only system remaining in the entire basin that provides nursery habitat to sustain mass golden perch recruitment [growth] events.”
It said the proposed return to a natural drying and wetting cycle in Lake Cawndilla could have a “seriously detrimental” effect on golden perch populations, which would be unlikely to reach the juvenile stage.
“Loss of this habitat as a golden perch nursery would impact the food supply of piscivorous waterbirds species and may therefore have adverse impacts,” the analysis said.
The MDBA said government had also failed to acknowledge the Lower Darling River Endangered Ecological Community in its proposal.
“This is a significant omission, as the legislation effectively applies endangered status to all native fish and aquatic animal life within [the Menindee Lakes area].”
The future of the Murray-Darling Basin Plan has been called into question by NSW and Victoria. (Photo: www.abc.net.au/news)
Project a ‘once-in-a-lifetime opportunity’
A spokeswoman for the NSW Department of Industry said the proposal would be released for community consultation soon.
“The issues raised by the MDBA analysis are being incorporated into the project proposal,” she said.
“This project is a once-in-a-lifetime opportunity to improve the efficiency of the Menindee storages, and return a significant amount of water lost through evaporation to the environment.”
She said it was too early in the process to prepare an Environmental Impact Statement, which would be started this year and would include a “formal assessment” on the golden perch.
“Initial discussions with NSW environmental agencies have focussed on best-practice fish passage, fish breeding, bird breeding and vegetation in in-stream [environment] requirements, to ensure they are reflected in the final proposal.”
An MDBA spokeswoman said the NSW Government had addressed many of the issues, and “has committed to continuous assessment throughout design and implementation”.
The NSW Government has until 2024 to deliver the project.
The Greens have lodged a disallowance motion in the Senate to block changes to the Murray-Darling Basin Plan, which would affect funding for the 36 Sustainable Diversion Limit projects.