Each river in the Basin is managed by the MDBA or a state body, depending on its location.
The MDBA manages and operates the River Murray on behalf of the New South Wales, Victorian and South Australian governments because the river flows through all three states. Water in the River Murray is shared based on the rules set out in the Murray–Darling Basin Agreement.
Other rivers in the Murray–Darling Basin are managed by the states. Each state and territory manages its dams and water distribution differently.
The map below shows who is responsible for managing the different rivers and dams in the southern Basin.
The Murray–Darling Basin Authority operates the River Murray system up to the border of South Australia. The River Murray system includes the waterways, storages, weirs and locks of the River Murray in the southern Basin. The MDBA manages:
- the River Murray and all its effluents (outflowing streams) and anabranches (streams that leave and re-enter the river)
- tributaries entering the River Murray upstream of Albury
- the main storages in the River Murray system — Dartmouth Dam, Hume Dam, Yarrawonga Weir and Lake Victoria
- the weirs and locks along the River Murray from Lock 15 at Euston to Lock 7 at Rufus River
- the Darling River downstream of Menindee Lakes (management is shared with NSW).
South Australia manages the parts of the River Murray system and the weirs and locks downstream of the South Australian border, including the Lower Lakes Barrages.
The states have responsibility for the other major storages with tributaries that connect to the system:
- Lake Eildon
- Burrinjuck Dam
- Snowy Mountains storages (federally owned)
- Menindee Lakes (although the MDBA has the right to direct releases when total storage within the Lakes is above 480 gigalitres).
- Learn more about the River Murray infrastructure managed by the MDBA.
River operations
Operating the river involves storing water and delivering it to water holders and communities. It is separate to the process of allocating water.
Prior to European settlement, First Nations people maintained and cared for the land and water that sustained them. When European farming practices became common, people started using a lot more water. Infrastructure was built to get water to different places like farms and communities and dams were built to store it.
River operators make decisions such as how much water should be released, and when to release it so that it gets to the right places on time.
These decisions help minimise water losses.
The MDBA’s role in river operations
The MDBA calculates the volume of water that will be released from the River Murray system to meet demands, but does not own or control any water. The MDBA can only release water from storage to meet state orders or system demands.
The MDBA directs the operation of the River Murray System to meet the states' needs.
This includes:
- sharing water in the River Murray between the three states
- managing infrastructure such as dams, weirs and locks
- managing salt interception schemes
- overseeing maintenance of existing assets
- constructing new infrastructure for delivering water.
The Murray–Darling Basin Agreement sets out the MDBA’s responsibilities for operating the river. It provides operating rules for the MDBA to follow.
The MDBA is also required to operate the river in a way that meets specific objectives and outcomes that relate to the health of the river system, communities and surrounding environments. It is audited against these objectives and outcomes each year.
River management structures
The MDBA is responsible for infrastructure in the River Murray from below the Menindee Lakes to the South Australian border. Authorities in each state manage the physical operation of the structures in the other parts of the River Murray and in other rivers in the system.
There are four main types of structures that help in managing water.
- Water storages (dams or reservoirs) capture large volumes of water so water is reserved when there is a drought.
- Weirs are structures built in rivers and irrigation channels to regulate the flow of water. They can also raise the river level to allow boats to move through the rivers more easily.
- Locks are chambers built next to some weirs. They allow boats to pass through weirs by raising and lowering the river level.
- Barrages are a series of weirs built at the end of a river to prevent sea water from entering the river system.
There are 14 weirs and 10 locks in the river, and five barrages at the Murray Mouth.
There are also 18 salt interception schemes, which are pumps that divert around half a million tonnes of salt away from river catchments each year.
Find out more about the infrastructure managed by the MDBA.
How the MDBA approaches water management in the River Murray and the Basin
The Murray–Darling Basin Agreement sets out what the MDBA is responsible for in operating the river. The agreement provides operating rules for the MDBA to follow. There are separate objectives and outcomes that the MDBA is audited against each year.
To support the environment as well as Basin communities and industries, the MDBA aims to manage water resources in the River Murray system sustainably. The MDBA uses science and research and water modelling data when managing the system.
When executing the Basin Plan, the MDBA considers many different conditions and circumstances. Changes in the Murray–Darling Basin, including climate change and new land uses, must also be taken into account. It considers the health of the entire Basin, and collaborates with Basin state governments and the Australian Government to find the best outcomes for everyone.
