Australia’s largest renewable energy project is charging ahead, with advancements on multiple fronts despite some temporary delays.
Snowy Hydro has provided an update on the works, which will see the Tantangara and Talbingo dams linked and a new underground power station built.
Tunnel boring machines (TBMs)
Florence: TBM Florence is excavating the 17km headrace tunnel, which will connect the underground power station to the upper Tantangara reservoir, with the machine now more than 3km into the headrace tunnel.
Lady Eileen Hudson: TBM Lady Eileen Hudson is excavating the 6km tailrace tunnel, which will connect the underground power station to the lower Talbingo reservoir. The machine has now completed 85 per cent of the tailrace tunnel, having already completed the 2.85km main access tunnel. The tunnel is now being used by workers to access the power station caverns.
Kirsten: TBM Kirsten is excavating the very steep, 1.6km Inclined Pressure Shaft (IPS) connecting the underground power station to the headrace tunnel. The machine has excavated 14 per cent of the shaft to date, and Snowy Hydro expects the performance of its tunnel boring machines to continue to vary in line with ground conditions.
TBM4: In December 2024, the New South Wales Department of Planning, Housing and Infrastructure approved Snowy Hydro’s application to deploy a fourth tunnel boring machine. The machine will help protect the delivery timeline by boosting the project’s ability to tunnel through a complex geological fault zone. Work to prepare for the launch of the machine is underway and is set to begin excavation by the end of 2025.
Power station caverns
Development of the Snowy 2.0 power station complex is progressing, with excavation and installation of rock support within the caverns more than 35 per cent complete.
The transformer hall is now almost 50 per cent excavated by volume and the machine hall is now 28m deep.
The drill and blast tunnels, which provide access to various levels within the caverns and other parts of the power station complex, are now more than 93 per cent complete.
Additionally, excavation of the 266m-long collector waterway tunnels, which will pass water from the power station to the tailrace tunnel and onto Talbingo reservoir, is 80 per cent complete.
Upper reservoir intake
A 40m-high tower crane is assisting with construction logistics in the Tantangara intake pit, where the project’s first permanent concrete structures are being built.
More than 6600m3 of concrete have been poured so far.
Lower reservoir intake
A total of 370m has been excavated from both ends of the connection tunnel, which is 825m long and will create a connection between the Talbingo intake structure and the tailrace tunnel.
A 70m tower crane has also been installed to lift heavy equipment and materials in and out of the intake pit.
Marica surge shaft
Excavation of the 240m-deep and 28m-wide Marica surge shaft has now passed 151m. The shaft will provide water storage when Snowy 2.0’s power station starts up.
When the station is shutting down, the Marica surge shaft will also provide pressure relief in the headrace tunnel. Once completed, it will be one of the widest and deepest operational shafts in the world.
Downstream surge shaft
Excavation of the upper chamber for the downstream surge shaft is now 68 per cent complete.
This shaft will be approximately 200m high and provide water storage when the power station starts up in pumping mode and pressure relief in the tailrace tunnel when the power station starts in generation mode.
Restart after work stoppages
Underground work on Snowy 2.0 has been progressively restarting throughout the last half of March 2025.
Operations for all three tunnel boring machines are now underway, as well as power station drill and blast cavern excavation.
Above ground work was not impacted and continued throughout the period underground work was stopped.
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