From desert to inland sea as 800 billion litres flows into Menindee Lakes

Menindee Lakes, one of the largest lake systems in the Murray-Darling Basin, are filling fast with the biggest water inflows in five years, allowing releases into the Baaka-Darling River downstream.

The lakes are now almost half full with about 800 billion litres of water, rising by about 17 billion litres a day during the past week, the Murray-Darling Basin Authority said. WaterNSW estimates the storages in far western NSW will end up swelling to as much as 1 trillion litres from the current inflows.

“It’s just a sea of water, stretching as far as you can see,” said Graeme McCrabb, a local grape grower and tourism advocate. “It’s just staggering.”

Mr McCrabb, who helped reveal the mass fish kills near Menindee in early 2019, said the sight of the lakes filling up has drawn visitors and helped local businesses flourish.

“It’s a morale and emotional boost,” he said. “Community businesses are thriving – the novelty just doesn’t wear off.”

Lake Menindee is filling fast, prompting authorities to start some releases to ensure the lower Darling River also gets a drink. Credit: Brook Mitchell/Getty Images

The influx of water down the Barwon-Darling River means control of the Menindee Lakes system has reverted to the Murray-Darling Basin Authority.

Under an agreement between NSW, South Australia and Victoria, the Authority can access the lakes’ water when the storage exceeds 640 billion litres, or 640 gigalitres. NSW takes back control when levels drop below 480 GL.

An aerial view of Lake Menindee at sunset, where conditions are the best in years.Credit: Brook Mitchell/Getty Images

The Authority has used its control to start releasing as much as 3.5 megalitres a day for the coming three weeks into the lower Baaka-Darling River. The 20-30 ML that it will release will amount to about 4 per cent of the inflows.

“As the most significant volume of water to enter the lakes in five years, it’s critical that we draw on this water carefully and maximise the benefits to everyone with a stake in this resource,” said the Authority’s executive director for river management Andrew Reynolds.

“The releases will start slowly to mimic natural river systems, providing connectivity between the Darling and Murray systems – something that would have occurred to a much larger extent if the water wasn’t captured in the Menindee Lakes.”

A kangaroo struggles to escape from a muddy pool in January 2019.Credit: Nick Moir

Mr McCrabb said the lakes had been rapidly drained in 2017 to meet the needs of downstream users, leaving communities and ecosystems exposed when conditions suddenly turned dry.

He called on authorities to review the trigger points, saying so-called active storage levels should be the guide rather than gross totals since 170 GL was effectively inaccessible and shouldn’t be counted.

“If we do exactly the same thing, what lessons have we learnt?” Mr McCrabb said.

Graeme McCrabb on his tinnie in the Darling River, floating among dead Murray cod and other fish just after the second of three big fish kill events near Menindee in January 2019.Credit: Nick Moir

He supported the release of water from Menindee saying the Lower Baaka-Darling was also in need of a good drink.

Still, water should be kept in the lakes system for as long as possible as the area is an important breeding site for the golden perch and other fish species. The lakes’ importance has also grown as the Murray and Murrumbidgee become increasingly regulated river systems.

The Menindee Lakes are a system of nine large, shallow lakes in far-western New South Wales. There is now enough water to open the gates between Lake Pamamaroo and Lake Menindee.Credit: Brook Mitchell/Getty Images

According to the NSW government, the abundance of golden perch “has dramatically decreased in the Murray-Darling due to migration obstruction and the alteration of flow regimes and temperature stratification following the construction of weirs and dams”.

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