Milton Drain Backflow Prevention

Delivered for Brisbane City Council, the Milton Backflow Prevention Device was a complex design and construct project completed within an extremely constrained site between Coronation Drive and the John Oxley Centre.

The project involved constructing a backflow prevention device, incorporating a two-stage temporary cofferdam system to manage water ingress from both the Brisbane River and the surrounding catchment. Working within a narrow 5-metre corridor, McIlwain adopted innovative construction methodologies including crane-assisted excavation, micropiling, shotcrete stabilisation and the construction of a reinforced concrete flood mitigation structure. Major concrete pours and lifting activities were carefully coordinated under lane closures on Coronation Drive, with much of the work undertaken at night to minimise disruption. Despite constrained site conditions, seasonal weather challenges and complex staging requirements, the project was successfully delivered with minimal impact on traffic and surrounding stakeholders, showcasing McIlwain’s expertise in delivering complex infrastructure in highly visible and challenging urban environments.