Restoring Daintree riverbank

This reinforced riverbank, just upstream from the Daintree River ferry crossing, was well underwater in the recent flooding rain – so we’re happy to report it has emerged unscathed to continue to do its job of stopping erosion.

One hundred metres of this riverbank was restored last year. Erosion problems had been worsening for years and Cyclone Jasper accelerated things in 2023, sweeping chunks of riverbank down the river and threatening the road running alongside the river.

Our solution, working with partners Neilly Group Engineering, was a combination of engineered rock work, earthworks and revegetation (mangroves, grasses and trees). And tree rootballs were embedded into the rock wall to better protect the mangrove plantings from flooding and to begin to replicate habitat conditions in established mangroves where large logs and branches collect and provide fish habitat.

The reinforced riverbank has now gone through multiple high rainfall events, with the latest nearing record high flows. Mangroves growing on the rockwall’s benching were the only part of the design that was significantly affected in the March flood. They will recover as tidal flows bring more mangrove seedlings from nearby vegetation.

Terrain NRM partnered with the Douglas Shire Council and Jabalbina Rangers for this project, which aims to stop an estimated 1,200 tonnes of fine sediment a year from washing down the river and out to the Great Barrier Reef lagoon

Terrain NRM’s Zack Severino says revegetation is the long-term solution, after a combination of rock and earthworks.

“We were dealing with a sheer drop. With every storm, more soil was getting washed away. Now we have a reinforced riverbank. And the upland area has been planted out with native, fast-growing trees to get a good root system embedded. Mangroves have been planted on the benched areas to catch sediment and more seedlings, so that’ll also help to secure the riverbank, and also filter the water.

The ‘Daintree Wetlands: Reef Coastal Restoration in the Lower Daintree’ project is being delivered by Terrain NRM through funding from the Australian Government’s Reef Trust through their Reef Coastal Restoration Program grant.