New works to stabilise eroded stretch of Mary River

New works have started on the Mary River near Kenilworth to prevent riverbank erosion and save destructive fine sediment from reaching the Great Barrier Reef.

The riverbank will be reprofiled and timber piling installed before being revegetated with native riparian seedlings suited to flood impacts experienced on the Mary River.

It's estimated that following the completion of works, sediment flow to the Great Barrier Reef will be reduced by 2430 tonnes a year.

The Mary River Recovery Project is funded by the Great Barrier Reef Foundation and the Australian Government’s Reef Trust.

It’s a collaboration between Burnett Mary Regional Group (BMRG), the Mary River Catchment Coordinating Committee (MRCCC)and Alluvium working with multiple partners, stakeholders and landholders.

A report prepared by Alluvium says the site 1km upstream of Kenilworth incurred significant bank and floodplain scour during the 2022 floods, which resulted in bank retreat of up to 50 metres and loss of riparian vegetation.

Approximately 77,000 cubic metres of sediment loss occurred from this site between 2008 and 2022.

The establishment of remnant standard riparian vegetation will help reduce rates of bank erosion on the Mary River.

The pile fields will provide short-term erosion protection by reducing the velocity of water flow and stress to enable the successful replanting of native vegetation.

As the piles decay over 10-15 years, the vegetation and associated root networks will also help to reduce the rates of bank erosion.

About 250 metres of riverbank will be reprofiled to its natural state.

GWT Earthmoving has been engaged to assist with the project and MRCCC will undertake the revegetation.