Hydro Tasmania Executive General Manager Assets and Infrastructure Jesse Clark said the trash screen was a critical piece of infrastructure that prevented damage to the power station.

"It’s essentially a giant sieve that sits over the intake opening to stop big rocks, logs and tree branches entering the power station,” said Mr Clark.

Hydro Tasmania’s consulting business Entura developed an innovative approach to installing the trash screen that allowed it to be installed without draining the lake.

A specialist diving team from Tasmanian Divers Group removed the old trash screen and installed the new one, with a crane lowering the screen pieces down to the divers who carefully placed them underwater.

Mr Clark said the project team had gone above and beyond to ensure minimal impacts on stakeholders.

“The project staff worked closely with our community engagement team to reduce impacts. Lake Trevallyn is a shared resource, and this approach has ensured water continued to be available for drinking, farming and recreational use,” said Mr Clark.

Installing the trash screen was technically challenging. While the dive supervisor on the boat had a set of drawings and procedure documents, the divers had to remember a lot of information while working underwater.

Mr Clark said the diving team had carried our highly specialised tasks in challenging conditions.

“The diving team has done an incredible job. Everything takes longer underwater, and they can’t see much further than half a metre in front of them,” said Mr Clark.

“The divers wear a lot of hats. If you did this work on land, you’d have separate people doing each job. The divers have to do everything – they’re riggers, fitters, welders and surveyors.”

A number of local businesses were involved in the project. The Engineering Company manufactured the trash screen and Billings Cranes carried out the lifting operations.

To prevent corrosion and increase longevity, the steel of the trash screen was coated with a new protective paint system that it is expected to extend its life from 20 years to 40.