Central West Orana Renewable Energy Zone Stormwater Installation

Trazlbat delivered the construction of a major stormwater drainage network incorporating reinforced concrete pipelines, drainage structures, headwalls, and associated civil works. The project was designed to improve stormwater conveyance, manage runoff effectively, and provide long-term drainage capacity for the surrounding development.

The works included extensive excavation, installation of reinforced concrete pipework and drainage structures, construction of headwalls and scour protection measures, and completion of all associated structural and reinstatement works required to deliver a fully operational stormwater system.

Scope of Works

• Excavation and trenching for stormwater pipelines, subsoil drainage lines, and associated drainage structures.
• Supply and installation of reinforced concrete pipe (RCP), including:
  • Approximately 475 metres of DN750 RCP.
  • Approximately 80 metres of DN600 RCP.
  • Approximately 65 metres of DN450 RCP.
• Installation of precast drainage pits and subsoil drainage systems.
• Placement of blinding concrete for drainage structures and pipe foundations.
• Supply and installation of precast concrete headwalls, including multiple-cell and single-cell configurations across various pipe diameters.
• Backfilling, placement, and compaction of trench excavations.
• Construction of scour protection measures at drainage outlets and discharge locations.
• Installation of formwork, reinforcement, and concrete for associated structural elements.
• Completion of discharge transition works and finishing activities around headwalls and outlet structures.
• Testing, quality assurance, and site reinstatement works upon completion.

Project Challenges

• Managing construction activities during periods of excessive rainfall and prolonged wet weather.
• Maintaining trench stability and safe working conditions in saturated ground conditions.
• Controlling groundwater and stormwater ingress within open excavations.
• Protecting newly installed drainage infrastructure from weather-related impacts during construction.
• Maintaining project progress and programme commitments despite adverse site conditions.
• Ensuring compaction, concrete placement, and quality control requirements were achieved during challenging weather events.