Marengo Basin Dam Safety Upgrade

Major dam safety upgrades and water infrastructure improvements to strengthen the structural integrity and long-term performance of Marengo Basin.

Scope

Keystone Civil was engaged by Barwon Water to deliver the Marengo Basin Dam Safety Upgrade, improving the structural integrity and operational reliability of the water storage basin that supports potable water supply to the Apollo Bay region.

Early works included installation of approximately 180 metres of DN250 and DN300 water mains, decommissioning of existing pipelines, access track upgrades and installation of a new gate valve.

Main works involved construction of a stabilising buttress, seepage collection system, outlet filter diaphragm and crest capping, with rock riprap protection to strengthen the embankment.

Further works included concrete spillway upgrades, outlet pipe relining and installation of a new hydraulic power unit and associated instrumentation to improve the basin's long-term performance.

Project Delivery

Working within a high-rainfall and environmentally sensitive environment, Keystone coordinated closely with Barwon Water and SMEC to manage design refinements, construction sequencing and environmental controls.

The project presented challenging ground conditions, including acid sulfate soils, requiring careful consideration of excavation activities and environmental risks. Management of these conditions formed part of the broader environmental approach, alongside sediment and erosion controls implemented to protect the surrounding environment and water infrastructure.

Keystone worked collaboratively with Barwon Water and the design team to address emerging site conditions, refine construction methodologies and maintain progress while prioritising dam safety.

Sustainability initiatives included collaboration with Eastern Maar to repurpose seven tree stumps removed during construction for use as fish habitat within local waterways.