Lake King William – Approach Channel, Intake and Downstream Portal Excavation Works

LocationLake King William, TAS
ClientHydro Tas
Key worksDams

The project involves construction of the intake excavation and downstream portal for the first stage of a new water conveyance directing water from Lake King William down to the Tarraleah Power Station. The 2 excavation sites will eventually be connected by a tunnel to allow the water to be piped through the surrounding mountains.

A plastic concrete cut-off and wave bund coffer dam were first constructed to protect the intake excavation from the rising lake levels and allow excavation to continue unimpeded. Excavation of ~130,000m3 of glacial soil and ~120,000m3 of dolerite rock is required at the intake site to reach the invert of the future tunnel.

Ground support is required to protect the steep excavation batters at both excavation sites, with a significant amount of rock bolts and shotcrete to be installed.
The project is due to be completed mid-2024.