February 13, 2023

Extensive repair and maintenance works to the Morwell River Diversion (MRD) structure at the Yallourn mine following an unprecedented flooding event in 2021 are complete, says Greg McIntyre, EnergyAustralia’s Head of Yallourn. 

“During June 2021, an extreme rain and flood event – the largest since records began 60 years ago – caused flooding of the Morwell River. It caused more than 30 times the average flood volume of water to run through the MRD, an embankment created to carry the river through the mine. 

“The flood event resulted in cracking in one part of the MRD structure. Failure of the MRD would have resulted in the Morwell River inundating the coal mine. This would have impacted power production at Yallourn power station, which provides up to 22 per cent of Victoria’s energy supply. 

“The Victorian Government declared an energy emergency and provided timely approvals so we could undertake urgent repair works to the MRD. A multi-agency Yallourn Emergency Response and Recovery Project was assembled to oversee the works. 

“We’re pleased to advise that all works are now complete in the MRD incident area.  

“We appreciate the strong support of the Victorian Government, local community, unions, regulators and especially our Yallourn workforce during this time.” 

The repairs included: 

  • Relining a section of the MRD by replacing the clay liner with an engineered layer of clay and grading the surface to improve surface water run-off. 

  • Both the low and high flow channels have had cracking repaired and have returned to service. 

  • EnergyAustralia received approvals for works to temporarily divert water flows away from the MRD where it runs through the Yallourn mine. All diversion works have now been built. 

Throughout the execution of the repair works, EnergyAustralia has met strict environmental conditions set by a number of state government agencies. 

EnergyAustralia will continue to work with Earth Resources Regulation to implement further improvements to maintain the integrity of the MRD structure.