The trial
To improve connectivity between the northern and southern Murray Darling Basin, environmental inflows from the Barwon-Darling will be released from Menindee Lakes when the lakes are a shared resource.
Prior to the trial, environmental flows protected under active management procedures in the Barwon-Darling would arrive at the Menindee Lakes, then be shared between NSW and Victoria at the bulk level under the Murray Darling Basin Agreement, before being allocated to licence holders at the retail level.
Under the trial arrangements, the environmental releases will be shepherded through the remaining length of the Murray Darling system, safeguarding against the current gap that exists in our ability to protect the flows. This means we can ensure environmental flows are protected from Queensland all the way to the Murray mouth for the first time.
Basin states requested the MDBA to prepare a plan to implement the trial in October 2023. NSW has been working with the Basin states and Commonwealth on implementing the trial since then. The inflows being experienced into Menindee Lakes in May 2024 present an opportunity to commence the trial now.
How the trial will work in practice
In May 2024, Basin states agreed to undertake the first trial to protect environmental water flowing from the northern to the southern Murray Darling Basin. The trial requires NSW and Victoria will release their respective 50% shares of the inflows for environmental purposes.
It’s important to note that the water being used under the trial is additional water that is protected under active management rules, which have been in place since December 2020. See Active management
To date, water users in the Murray have benefited from this additional water. Under the trial, the additional water will now be recognised.
The trial is expected to last for 12 months, starting May 2024 until June 2025.
Trial principles
Basin states and the Commonwealth have agreed to run the trial under the following principles to guide decision making for the trial. The principles are:
- The held environmental water (HEW) component of the northern Basin active environmental water (NBAEW) is additional environmental water sourced from NSW tributaries that would not have flowed into Menindee Lakes prior to water recovery for the environment.
- The HEW component of the NBAEW should be protected through the Menindee Lakes, with return flows delivered to downstream environmental sites, including to South Australia, after deduction of an assumed use to account for the incremental loss due to the higher flow in the river.
- The water resource availability of each southern basin State should not be enhanced or diminished by this type of watering action.
- Existing mechanisms should be used where they are fit for purpose, but new ideas that are simple to implement should be considered.
Northern Basin Connectivity Program
Read more about the Northern Basin Connectivity Program