Abergeldie completed works immediately below the spillways of Queensland’s Wivenhoe, Somerset and Borumba Dams to repair damage caused by overtopping and emergency releases during the 2011 and 2013 floods.
At Wivenhoe dam, most of the repair works were to the recreational area on the southern embankment of the river below the dam wall. Roads were rebuilt, pavements stabilised, new canoe access tracks created and extensive earthworks carried out to stabilise and re-profile the river embankments.
At Somerset Dam, extensive remediation works were carried out to the severely eroded right bank of the Stanley River. Abergeldie installed a new reinforced concrete spillway training wall, carried out repairs to scours, installed a new access road, replaced guardrails and handrails and installed rock protection and rip rap to stabilise embankments.
Works at Borumba dam included remediation of the dam’s concrete embankment toe, valve house, spillway and plunge pool areas, and reinstatement of handrails and access pathways. To stabilise the river banks and bed, rock rip rap was placed downstream of the spillway and steel reinforced rock protection was installed adjacent to the spillway itself.
At all three sites, care was taken to protect the riparian habitat. At both Wivenhoe and Somerset dams there are important populations of Australian Lung Fish, both within the dam reservoirs and in the rivers downstream. The waters above and below the Borumba dam are home not only to Australian Lung Fish but also to the endangered Mary River Turtle, which is found only in this one location.