Federation Council has confirmed the reliability of the 2024 Corowa, Howlong and Mulwala Flood Study, particularly the key flood level estimates for Mulwala, following a comprehensive independent peer review. This marks a significant step forward, allowing the Council to progress to the next critical phase: the Flood Risk Management Study and Plan (FRMS&P).
The Peer Review, undertaken by Venant Solutions, was commissioned by Council in May 2025 following significant public interest and community concern regarding the higher proposed 1% annual exceedance probability (AEP) Murray River flood levels for Mulwala.
The Peer Review concludes that the 2024 Flood Study is consistent with current best practice and is suitable for floodplain purposes. Crucially, the review found that the flood frequency analysis (FFA) for Yarrawonga provides a reliable estimate of the 1% AEP design flow, meaning the resulting flood levels at Mulwala are appropriate. The TUFLOW hydraulic model used in the study was also deemed well setup and appropriate for representing Murray River flood levels.
Federation Council Mayor, Cr Cheryl Cook said the Peer Review was vital to provide the community with confidence in the technical foundations of the Flood Study.
"We heard the concerns, especially from our Mulwala residents, and committed to an independent assessment before moving ahead," Mayor Cook said.
"The finding that the Mulwala flood levels are appropriate gives us the certainty we need to plan for the future."
With the Flood Study findings validated, the Council is now commencing the Corowa, Howlong and Mulwala Flood Risk Management Study and Plan (FRMS&P) in October 2025. This project, like the Flood Study and Peer Review, is substantially funded by the NSW Government Floodplain Management Program.
The FRMS&P will:
Identify and assess potential mitigation options to reduce flood damages for the three townships;
Assess all options based on benefit versus cost;
Formulate a Floodplain Management Plan which will identify actions to protect life and property; and
Develop new flood-based planning and development controls for Council to adopt.
Mayor Cook emphasised the importance of community involvement.
"The risk management process will require the input of the community through the Flood Risk Management Committee," she said.
"I encourage all residents to stay engaged as we work to identify the best strategies to reduce the flood risk across the Federation Council area."
In May 2025, Council resolved to continue applying the planning controls and flood planning areas defined in the existing 2012 Local Environmental Plan (LEP) until the FRMS&P is completed and new controls are formally adopted. The outcomes of the new Flood Study will, however, continue to be considered in the review of new development applications, with applicants made aware of the updated flood level information.
Mayor Cook said Council remains committed to a transparent and risk-averse approach.
"This dual process - validating the science and then moving into practical risk reduction, ensures we are making informed decisions that will create a strong, sustainable reality for the Federation Council Region." Residents are encouraged to stay engaged on this project by signing up to Council's electronic newsletter or visiting Council's website.
FAQ: What residents need to know
Question |
Answer |
|---|---|
Is the 2024 Flood Study reliable? |
Yes. An independent peer review by Venant Solutions found the 2024 Flood Study is consistent with current best practice and suitable for floodplain purposes. |
Are the new flood levels for Mulwala correct? |
Yes. The review specifically found that the Flood Frequency Analysis (FFA) for Yarrawonga provides a reliable estimate of the 1% AEP flow event, confirming the flood levels at Mulwala are appropriate. |
What happens now? |
Council is moving to the next stage: the Flood Risk Management Study and Plan (FRMS&P), which is due to commence in October 2025. |
What will the FRMS&P do? |
It will assess options to reduce flood damage in Corowa, Howlong, and Mulwala, develop mitigation measures, and propose new, up-to-date flood-based planning and development controls. |
Have the flood-based planning controls changed? |
No, not yet. Council has resolved to continue using the existing 2012 Local Environmental Plan (LEP) flood planning areas for land use and development decisions until the FRMS&P is complete and new controls are officially adopted. |
Were any issues found in the review? |
The review indicated that the flood flow estimates for Doctors Point and Corowa may be underestimated. This issue and others raised in the review will be investigated during the initial stage of the FRMS&P. The underestimation at Corowa/Doctors Point could mean higher riverine design flood levels in Howlong and Corowa, but this would not significantly influence flood levels at Mulwala. |
Was the assumption about the irrigation channels confirmed? |
Yes. The hydraulic model assumed that the gates for the Mulwala Canal and Yarrawonga Main Channel are closed during significant flood events. Goulburn Murray Water's representative has confirmed that outflows into the Yarrawonga Main Channel would not be occurring during a Murray River flood event. |
