How River Murray water is allocated

We allocate River Murray water to South Australian entitlement holders according to the rules in the Water Allocation Plan for the River Murray Prescribed Watercourse.

Our factsheet on Allocating water from the River Murray explains how it works.

What happens in low water years?

To help you plan for a dry water year, we announce potential water allocations from April onwards each year, using probability scenarios and the likelihood of allocations improving. The diagram below outlines the general timeline of allocation announcements.

In dry years, South Australia does not receive its annual Murray-Darling Basin Agreement Entitlement of 1,850 GL; instead, we receive a third share of available River Murray water.

In extremely dry conditions:

• 2 per cent of South Australia’s Dilution and Loss Entitlement may be used to make an initial allocation to Class 3 (High Security) (irrigation) and Class 8 (environmental land management allocations) entitlement holders. This is to ensure access for critical human water needs (stock, domestic or industrial) from irrigation systems.
• The initial volume of critical human water for metropolitan Adelaide is now limited to 100 GL to allow earlier allocations to irrigators and other water users. Other water sources are available to metropolitan Adelaide, including local reservoirs, the Adelaide Desalination Plant and water set aside in Basin Storages for critical human water needs. This frees up 50 GL to provide up to an 8 per cent increase in allocations. Other than in exceptional circumstances, the 8 per cent benefit for irrigators is expected to be maintained in full until 30 June 2024. The commitment is implemented in a way that has no impact on prices or water security for SA Water customers.

View this video to learn more about River Murray Water Sharing and Allocation Processes.

Water resource availability

The Murray-Darling Basin Authority provides monthly updates on the water resources conditions across the Basin, including:

• recent inflows to the Basin
• volume of water available in Murray-Darling Basin controlled storages
• the Bureau of Meteorology’s three-month weather outlook.

For more information about River Murray operations and water resource conditions please refer to the weekly River Murray Flow Reports.

How water is shared between states

Water is shared between New South Wales, Victoria and South Australia according to rules in the Murray-Darling Basin Agreement, which is part of the Commonwealth Water Act 2007. The Murray-Darling Basin Authority operates the river on behalf of basin governments according to these rules.

This Murray-Darling Basin Authority video shows how sharing works between the states.

How much water South Australia gets

South Australia has an annual Entitlement of 1,850 GL under the Agreement. However, we do not receive the full amount every year; it can be reduced if water availability is limited when conditions are dry. In these years, South Australia receives a third share of all the available River Murray water.

Not all water available at the start of the year can be shared for allocation.

How it works

Each year, the Murray-Darling Basin Authority determines the volumes of water available for different uses, using this process:

1. A certain amount of water is put towards system conveyance and storage losses for the current year, and then to the Conveyance Reserve for the following year. This water is used to “run the river”.
   South Australia’s portion, called the Dilution and Loss Entitlement, is 696 GL. This provides for losses in our state from the border to Wellington and ensures that water of suitable quality for human consumption can be extracted before it flows into Lake Alexandrina. This water is not available for allocation. The other states do not report system conveyance volumes in their water availability records, so it is difficult to compare.
2. A certain amount is put to delivering water for critical human needs in each state. The volume required for critical human water needs is the minimum amount of water to meet: (i)
   core human consumption requirements in urban and rural areas, and (ii) non-human consumption requirements - a failure to meet these would cause prohibitively high social, economic or national security costs (s86A(2) Water Act).
3. South Australia’s critical human water needs volume is up to 204 GL, of which 150 GL is for metropolitan Adelaide. Over one million people rely on water from the River Murray – in metropolitan areas, regional towns across much of the state and in towns along the River Murray itself.

The total available water for each state to allocate to individual water entitlement holders is determined. This is based on many factors, including the amount of water in major storages and the minimum amount projected to be available over the next 12 months.

The states may allocate their total available water to entitlement holders in accordance with state statutory water sharing plans. In South Australia, these are called water allocation plans.

As with other states, not all of South Australia’s Entitlement is allocated for consumption purposes. This is to ensure that there is enough water for river health.

Why is the process different in each state?

River Murray water is allocated differently in each state because each has its own management approach. Each state has unique water products, unique industries and different rules and requirements about how and when water is allocated.

• New South Wales water sharing plans: Department of Planning, Industry and Environment website
• Victoria: Northern Victoria Resource Manager website.

Water sharing arrangements within each Basin state must comply with the rules and limits in the Basin Plan. Basin states must show how they are sustainably managing water resources in the Murray-Darling Basin by preparing and accrediting their Water Resource Plans. South Australia’s three Water Resource Plans are accredited.

To find out more about how water is shared between the states visit the Murray-Darling Basin Authority website on roles and responsibilities.

View water resource availability to find out about current conditions and how much water is available.