Customer: AGL Southern Hydro
Location: Bogong, Victoria, Australia.
Contract type: Design and Construct
Construction Period: 3 years
- 6.5 km of 5 m diameter hardrock tunnel constructed using a tunnel boring machine;
- 1.3 km of drill and blast tunnels;
- 250 m of 5 m diameter shafts;
- 5,000 t penstock liners;
- power station construction and installation of two 70 MW turbines.
AGL Southern Hydro awarded the design and construct (D&C) contract for the Bogong Power Development Project to McConnell Dowell in September 2006. Consisting of a network of tunnels and shafts and the construction of a new underground hydro electric power station, the Bogong Power Development Project is the largest hydro power project constructed in Australia in 25 years. Located in a picturesque national park near the Victorian ski fields at Falls Creek, the power station forms part of AGL Southern Hydro’s strategic energy framework for the supply of green peak demand power. It will harness the Rocky Valley and Pretty Valley branches of the East Kiewa River and existing water resources released from the Mackay Creek Power Station to generate 140MW of renewable power.
The Bogong Hydro Power Station is an underground structure, with the excavation of the station box is top-down excavation utilising secant pile walls, rock anchors and excavation in rock 25 metres below the surface. Approximately 30,000 cubic metres of material was excavated, after which the power station foundations were filled with more than 10,000 cubic metres of concrete. Pivotal to the success of the power station construction was the co-ordination of the mechanical equipment including turbines, generators, draft tubes, inlet valves and scroll casings. These significant individual pieces required installation as the power station was constructed from the depths of the excavation.
McConnell Dowell's engineers worked with our consultants in extensive value engineering workshops to reduce the price by A$30 million. The team realigned the tunnels and developed innovative materials-handling techniques for all tunnel rock.
With Bogong Village housing an Outdoor Education Centre and a significant bush trekking area, effective community involvement and engagement was a critical to delivering a successful outcome. McConnell Dowell were supportive in enhancing the services of both this centre with improved outdoor activities areas, and by providing upgraded walking tracks in the surrounding areas. Public and community interaction groups were regularly convened and awareness programmes kept stakeholders and local authorities fully informed throughout the entirity of the project. The sustainability focus of the project was extended to encompass the disposal of the tunnel rock spoil. The local Alpine Shire was able to use material to upgrade local roads in the area, particularly the high plains road to Omeo from Falls Creek.
AGL Southern Hydro’s Project Manager John Arnold spoke highly of McConnell Dowell's work on the Bogong Hydro Power Project, constructed in the alpine national park in Cobungra, Victoria.
“The statutory authorities cannot speak highly enough about the work done by McConnell Dowell. The work they are doing is being used as a benchmark for future projects.”