Water to South Australia from recent interstate flooding
Over the past few weeks, Western Queensland has experienced substantial rainfall and flooding as a result of ex-tropical cyclone Alfred. The floodwaters are making their way across two significant water catchments - the Murray-Darling Basin and the Lake Eyre Basin.
In the Murray-Darling Basin, while it is still early in the progression of these flows downstream, creating a high level of uncertainty, updated forecasting from the New South Wales Government indicates approximately 600 -1000 gigalitres (GL) is expected to enter the Menindee Lakes from late May to the end of June 2025. There are several variables which may impact the final volume of water that reaches the Menindee lakes, including the amount of seepage that occurs as the floodwaters make their way along the Warrego and the Barwon-Darling Rivers before entering the lakes, as well as the volume of water that is pumped out by upstream users in accordance with the relevant New South Wales Water Resource Plan.
The Menindee Lakes currently hold 675 GL (39%) of a possible storage volume of 1,730 GL. This means that there is sufficient airspace available within the Lakes to safely capture the estimated forecast inflows, and significant increases to flows at the South Australian border are not expected. In accordance with the Murray-Darling Basin Agreement, some of this water may be called upon to support South Australia’s Entitlement Flow. Further information about the storage of water within Menindee Lakes can accessed from the Water NSW Water Insights portal.
The majority of the rainfall associated with the recent flooding has occurred in the Queensland part of the Lake Eyre Basin and is flowing down the Diamantina/Warburton and Georgina rivers and Cooper Creek to Innamincka, the Coongie Lakes and Kati Thanda – Lake Eyre. Gauge data is sparse in this area, but satellite images show the peak has passed the South Australian border, meaning the water will travel through South Australia over the coming months. Water is already entering Kati Thanda – Lake Eyre from recent local rainfall in northern South Australia. The Bureau of Meteorology has forecast the Queensland floodwater will start filling Kati Thanda-Lake Eyre from approximately June onwards.
This information is accurate as of 1 May 2025.
For further information:
Department for Environment and Water: View the River Murray Flow Report
Bureau of Meteorology – Inland Rivers Flood Warnings: Check current flood warnings
Water Data SA: Visit Water Data SA
Water Insights Portal: Explore the Water Insights Portal
Murray–Darling Basin Authority: Access the Weekly Reports
