Solid construction progress is occurring at the Snowy 2.0 hydropower project, Snowy Hydro has said, despite the temporary halt of one of the project’s TBMs following the discovery of a surface depression.
In December TBM Florence, which is digging the headrace tunnel at Tantangara, was transitioning from soft material into harder rock conditions when a depression developed on the surface above the machine. At the time, Snowy Hydro said the integrity of the tunnel had not been compromised, and tunnelling was continuing while work to remediate the surface depression was carried out. A safety exclusion zone had been imposed around the surface depression.
Now in response to a report by the Australian Broadcasting Corporation, a statement on Snowy Hydro’s website says the TBM is temporarily paused while plans to remediate a surface depression above the Tantangara adit are finalised.
“Across the project, and as anticipated, the ground conditions encountered by the Snowy 2.0 TBMs are highly variable, ranging from soft, sandy ground to extremely hard rock,” the statement says.
“Complex and variable ground conditions are not unusual in such projects. Snowy Hydro and the Snowy 2.0 EPC contractor, Future Generation Joint Venture, are focused on delivering the project safely and in a manner respectful of the sensitive environment, while managing impacts caused by external events including Covid-19, high material costs, global supply chain constraints, labour shortages across the Australian construction industry and ongoing weather conditions.
“Commercial claims on construction projects are also common. As with other major infrastructure projects, Future Generation Joint Venture has experienced significant impacts from Covid resourcing and supply chain challenges. Claims submitted to Snowy Hydro by the contractor continue to be assessed and paid appropriately, in accordance with contractual requirements.”
Snowy Hydro says progress is occurring across a large number of Snowy 2.0 work fronts. At Lobs Hole, the Talbingo intake is well under way, the main access tunnel excavation by TBM Lady Eileen Hudson is completed and the emergency, cable and ventilation tunnel excavation by TBM Kirsten is close to completion.
It added that the Snowy 2.0 budget of A$5.9bn (US$4bn) remains unchanged since the project approval.
Snowy 2.0 is Australia’s largest renewable energy project. It will link Tantangara Reservoir (top storage) with Talbingo Reservoir (bottom storage) through 27km of tunnels and a power station with pumping capabilities. This will enable water to be released for energy generation at times of peak demand and pumped back to the top storage when there is excess renewable energy in the system, ready to generate again.
Source: Tunnels and Tunnelling Magazine
