Neilly Group (NG) designed remediation measures for a channel avulsion of the Fitzroy River, to prevent ongoing significant erosion under the Reef Trust IV program for Catchment Solutions. The site is located on Collinsdale Station, which is situated on the Fitzroy River, in Garnant, approximately 30km from Rockhampton. 

The Reef Trust IV remediation project included the rehabilitation of large-scale erosion, resulting from the partial avulsion of the Fitzroy River into the neighbouring Louisa Creek. Approximately 74,000 cubic metres of sediment has been eroded from the site over the past ten years. The works will prevent the ongoing export of approximately 4,233 tonnes per year of fine sediment to coastal waters, including the Great Barrier Reef Lagoon.

The works designed included:

  • Bank battering of a 10m high vertical bank in the channel avulsion path to stabilise the vertical bank and to obtain approximately 18,000 cubic metres of material to use as fill.
  • Landform construction to reduce the frequency of flood flows from the Fitzroy River through the placement of 18,000 cubic metres of compacted fill.
  • Rock armouring at select locations based on hydraulic modelling.
  • Excavation and spillway construction on an existing eroded farm dam to obtain topsoil for placement on the landform and bank battering works and to create a high-capacity off-stream watering point.

The works were funded under the Australian Government’s Reef Trust IV funding programme. The works were delivered by Catchment Solutions, with construction undertaken by JRT Group and construction supervision and RPEQ certification provided by Neilly Group Engineering.

Fitzroy River Basin, Rockhampton, QLD