Water levels at Menindee Lakes have fallen below an important threshold, triggering a change in how the water stored in the lakes is managed.
According to the South Australian Government's River Murray report issued on 9 October, storage at Menindee Lakes had fallen to 475 gigalitres (GL) on 7 October, down from 489 GL a week earlier.
While that might seem like just another change in water levels, the 480 GL mark is significant.
Why Is 480 GL Important?
Under the Murray–Darling Basin Agreement, water held in Menindee Lakes can be managed as part of the shared River Murray system.
However, when storage falls below 480 GL, the remaining water is no longer treated as part of that shared resource.
Instead, New South Wales takes responsibility for managing the remaining water, with a focus on local requirements.
The lakes do not return to shared management until storage rises above 640 GL.
It Wasn't That Long Ago They Were Getting a Big Drink
It wasn't that long ago that I visited Menindee Lakes when the system was getting a big drink.
There was plenty of water moving through the system, and it was a great opportunity to see the lakes receiving much-needed inflows.
I've included that video here for a look back at what things were like during that visit.
It's a reminder of just how much conditions can change in this part of the Murray–Darling Basin.
What Does This Mean for the Darling River?
Menindee Lakes plays an important role in regulating flows along the Lower Darling, which eventually joins the Murray River at Wentworth.
The change in management arrangements does not automatically mean releases will stop or that river levels will suddenly fall.
Decisions about future releases will depend on water availability, local requirements and operating conditions.
For communities along the Lower Darling, the important thing to watch now will be how much water remains in storage, whether further inflows arrive and how releases are managed over the coming months.
What Happens Next?
With storage now below the 480 GL threshold, management of the remaining water sits with NSW under the existing agreement.
We'll continue watching Menindee Lakes storage levels and any announcements about future releases into the Lower Darling.
For now, the main development is straightforward: Menindee Lakes has crossed an important management threshold, and NSW is once again responsible for decisions about the remaining stored water.
