About the Exploratory Works
Project need
Before the design of Snowy 2.0 can be finalised, Exploratory Works are needed to gain a better understanding of the underground conditions and confirm the suitability of the site for the power station. This requires excavating an exploratory tunnel.
It is important to note:
- Excavating exploratory tunnels are common practice internationally to inform design, and was completed for both Tumut 1 and Tumut 2 power stations.
- The underground power station for Snowy 2.0 will be located in the Ravine Beds geological unit, at much greater depth and in different rock conditions than Tumut 1 and Tumut 2 power stations.
Design and construction of excavations of the size and complexity proposed by Snowy 2.0 are highly dependent on the rock properties and structural geology at the potential locations. No existing Snowy Scheme tunnel or excavation currently intersects the Ravine Beds geological unit, and therefore it is extremely important to understand excavation conditions, water seepage, rock bedding and faulting conditions, particularly in the area of the power station. Exploratory Works has been proposed and is needed to ensure this critical information is available to finalise the design of Snowy 2.0.
Project description
The Exploratory Works are near the Lobs Hole area of the KNP and Talbingo Reservoir and are entirely within NSW. The nearest large towns to the Exploratory Works are Cooma and Tumut. Cooma is approximately one hour and 45 minutes drive (95 km) south-east of Talbingo Reservoir. Tumut is approximately half an hour drive (45 km) north of Talbingo Reservoir.
The Exploratory Works will involve construction of an exploratory tunnel to enable exploratory drilling and provide a greater understanding of the underground conditions at the Snowy 2.0 power station cavern. Several supporting elements will also be required to facilitate the construction of the exploratory tunnel. These elements are shown on the interactive map, summarised in the table below, and are detailed further in the EIS.
Summary of Exploratory Works elements
| Project element | Overview |
|---|---|
| Exploratory tunnel | An exploratory tunnel approximately 3.1 km long |
| Portal construction pad | An entrance structure at the western end of the exploratory tunnel. And an area for infrastructure, equipment and activities required for the construction of the exploratory tunne |
| Accommodation camp | A fully serviced accommodation camp catering for a construction workforce of up to 152 personnel |
| Access roads | 26 km of road upgrades and approximately 2 km of new roads to facilitate access to the project area |
| Barge access | The construction and use of two new barge ramps on Talbingo Reservoir at the existing Talbingo Spillway and Middle Bay |
| Supporting infrastructure | Provision of power, communications, water and waste infrastructure and services to the proposed construction sites |
| Excavated rock management | Up to 750,000 m3 of excavated rock to be placed within temporary emplacement areas within Lobs Hole or subaqueous placement within Talbingo Reservoir subject to management and monitoring |