Hydro Tasmania has marked a significant milestone on upgrades to the Tarraleah hydropower scheme, with the intake tower excavation now complete.
Almost a quarter of a million cubic metres of rock and soil were removed to create the deep excavation where the new concrete tower will be constructed. Tasmanian company Hazell Bros Group delivered the works over the past 27 months.
Entura designed an innovative plastic concrete cut-off trench. The trench protects the deep excavation from seepage from the mighty waters of Lake King William and provides flexibility for construction and the timing of future works associated with the intake excavation.
Hydro Tasmania’s Interim Executive General Manager, Construction, Tammy Chu, said it was an exciting time for the upgrade works project.
“This has been an impressive effort, removing 240,000 cubic metres of rock and soil and using 3,700 rock bolts (some up to 6 metres long). We overcame challenges with complex geology and typical Tassie winter weather. Plus local jobs were created, with a peak workforce of 30 people on the ground delivering this work,” Chu said.
The intake tower construction is the next planned phase of work. A tender for this work was recently released, marking another major project milestone.
Designed by Entura, the intake project includes a 30-metre-high concrete structure housing intake screens, a large steel gate, and an associated hydraulic hoist.
Work on the 950-metre connecting tunnel is also well advanced. It will connect the new intake to a future conveyance to feed water into the Tarraleah Power Station. Hazell Bros Group is working alongside tunnelling experts Tunnelling Solutions to complete around 260 blasts, removing 100,000 tonnes of material along the tunnel length.
These are essential upgrades on a scheme that has been delivering clean energy to Tasmania since the 1930s, making it one of our oldest schemes.
“Hydro Tasmania is proposing a major redevelopment, so Tarraleah will be ready to help meet the growing demand for energy and power the state for generations to come,” Chu said.
The Federal Government has committed up to $65M in funding for the upgrade works.
