Projects

Horsehead Creek Sewerage Retention Basin

In conjunction with Tasmanian Consulting Service, a design and construct project for the construction of four sewerage retention basins provided many challenges:

• No solid natural base
• Situated beside a tidal river
• Continuous Wet weather
• Working at Heights and Manual Handing challenges

The concrete slab of the basins was excavated to 2.5m below the natural surface level leaving between 2-3 metres of wall exposed above ground which was clad with colorbond. Additional excavation was required with a suitable base rock proving elusive so gravel was used to backfill to the required level. Each basin was 20m long, 8.5m wide and over 5m deep with all walls cast in-situ. As the basins were to be filled with liquid the long lengths of reo had an accuracy margin of only millimeters in the tying for concrete casting. The only way to access these basins was to climb in and out via scaffold.
The contract also involved the construction of several additional buildings and structures including a Control Room, Generator Building and Odour Treatment Plant along with extensive Roadworks and Landscaping.

Notes of interest:

• Over 110 tonne of reinforcement and 600m³ of concrete was used in the construction of the basins alone.
• Excavated material was mounded up and landscaped to provide a visual break for passing motorists and residents.

The Project Photos