Lake King William Upgrade Works

As a key component of Hydro Tasmania's (HT) major projects, the Lake King William (LKW) Upgrade Works marks the initial phase of the broader Tarraleah Redevelopment initiative. This project is set to replace the aging water conveyance infrastructure, which will double the power station's electricity generation capacity from 90 MW to 190 MW by increasing water inflow.

PSM was engaged to provide geotechnical and hydrogeological services, from site investigation and design through to construction phase support. Our key responsibilities included:

• Site investigation
• Geotechnical and hydrogeological model development
• Ground support design for the surface and tunnel excavation
• Digital engineering and BIM support
• Surface excavation and ground support construction phase services (CPS)
• Tunnel excavation and ground support designer CPS
• Geotechnical and hydrogeological model development
• Ground support design for the surface and tunnel excavation
• Digital engineering and BIM support
• Surface excavation and ground support construction phase services (CPS)
• Tunnel excavation and ground support designer CPS

• Significant geological structures.
• Open excavation and face support in quaternary glacial sediments and high-strength blocky rock.
• Over 40 m deep excavation adjacent to the lake.
• Tunnel excavation in high-strength blocky rock mass.
• Groundwater seepage/inflow during excavation.
• High variability in ground conditions.
• Remote site.

A “toolbox’ of flexible support types coupled with robust design verification throughout construction.

Drill and blast excavation methods and staged excavation sequence.

In surface and tunnel grouting to control the operational water leakage and ensure long term asset integrity.

Advanced observational methods such as LiDAR scanning of exposed rock faces.

3D modelling to proactively assess and reduce the risks of large-scale kinematic instability during the excavation.

PSM’s involvement spanned the project duration and provided practical solutions, which satisfied Hydro Tasmania’s project requirements and were able to be implemented by the contractor. Our extensive D&C experience bolstered HT’s delivery capabilities in proactively managing geotechnical construction risk.

Services: #Hydropower #Tunnelling #Geotechnical #Hydrogeology #LakeKingWilliamUpgrade