Black Hawk delivers 40 tonnes of boulders to repair weir

A BLACK Hawk helicopter has hauled 40 tonnes of boulders through the valleys of the Northern Rivers to repair a 100-year-old weir damaged by the 2022 floods and the former Tropical Cyclone Alfred last week.

In a first for flood recovery, the long-line helicopter operation airlifted 24 basalt boulders one at a time over four hours to the Lavertys Gap Weir on Wilsons Creek, to stabilise the eroded creek bank of the Mullumbimby heritage site.

A specialist marine contractor utilised tracked vehicles, floating barges, and helicopters to perform repairs on the creek bank at the southern end of the weir wall, which had suffered severe erosion during the floods.

A section of repairs that the Black Hawk helicopter could access as part of reconstruction.

The operation reduced the need to create new access tracks and minimised environmental disturbance around the catchment.

Minister for Recovery Janelle Saffin said Black Hawks were not typically used for reconstruction efforts.

“We had to think outside the box to ensure we could repair and protect a key piece of local history while ensuring Mullumbimby has a secure and reliable water supply for the future,” Saffin said.

“The sight of a UH-60 Black Hawk helicopter placing giant boulders at the weir site was a joy to behold and shows what is possible when different levels of government work together in the best interests of a community in need of recovery support.”

NSW Public Works Project Manager Richard Greenhill said it was a meticulous operation.

“By placing rock and engineered clay with precision, we’re building a durable barrier that will protect the weir from erosion and withstand future flood events,” Greenhill said.

“We’re addressing erosion that’s undermining the weir wall itself, which, if left unchecked, could compromise the structure.

The helicopter was able to weave through the narrow peaks and valleys to access the site.

“This is a collaborative effort involving the council, state agencies, traditional owners, and the landholder; everyone has played a role in making this possible.”

As part of the Northern Rivers Water and Wastewater Repair and Recovery Program, the $2.7 million critical repair is led by the NSW Reconstruction Authority, in collaboration with Byron Shire Council, and delivered by NSW Public Works.

Repair works are being completed without impacting the local water supply and are expected to be completed by early January.