Fred Haigh Dam Remediation

QLD
Sunwater
2020
562,000ML

storage capacity

130,000ha

catchment area

43m

max depth

30,000m³

downstream rubble re-positioned

Abergeldie was engaged by Sunwater as the head contractor to complete the Fred Haigh Dam Remediation project. The project involved stabilising the scoured banks and bed of the watercourse, and repositioning erosion deposits to create a seepage path for flow monitoring. This restoration addressed damage caused by the 2010 floods and Tropical Cyclone Oswald in 2013. The project was recognised as a finalist for the CCF QLD Earth Awards in 2020. For more information about the Fred Haigh Dam Remediation project, click here.

Scope of works

The works included:

  • Geotechnical stabilisation using rock dowel passive anchors and dental fill concrete to address a scoured area downstream of the spillway, removing loose rock and preparing surfaces. 
  • Bulk excavation and earthworks to reposition 30,000m3 of rubble downstream, and reshape the drainage channel along the Kolan River’s right bank to reduce ponding at the spillway’s toe.
  • Seepage monitoring was established on the cofferdam embarkment after drainage of water ponded at the spillway toe. 

Monitoring water flows to guard against flooding

The works downstream of the spillway required continuous monitoring of water flows and weather conditions to guard against potential flooding due to sudden increases in dam flows. To ensure safety, a flood evacuation plan was developed, and all personnel received site induction covering flood emergency response procedures. To handle the precise excavation and earthworks needed for reshaping the seepage path, a GPS system was deployed, enabling the creation of an as-constructed model.


Completing works in time for the fishing season

The project team worked collaboratively with Sunwater to ensure the works were completed to restore access to Lake Monduran for residents and tourists during the fishing season. The remediation works have repaired all damage caused by the flood and put in place preventative measures to withstand heavy rain periods in the future.