Hydro Tasmania’s first pumped hydro project back in the EPBC after expansion

Hydro Tasmania has had a second go at its EPBC referral for the first of three pumped hydro projects. 

The 750 megawatt (MW), 20 hour storage Cethana project is the first of three pumped hydro proposals revealed in 2019 as part of the company’s Battery of the Nation plan.

Seven years on, it has been referred to the EPBC a second time after being withdrawn in early 2025. 

It had been assessed particularly quickly in 2023, with federal bureaucrats taking just a month to decide that it needed EPBC oversight. 

The state-owned company says that new geotechnical and engineering work has increased the footprint of the project and as a result, it needs a new EPBC referral. 

The original plans on the left are smaller in scope than the revised ones on the right. Images: Hydro Tasmania

The project is part of Hydro Tasmania’s Mersey Forth Hydropower Scheme and is destined to support variable renewable energy sources in Tasmania and Victoria, once the Marinus Link undersea transmission cable is built. 

Environmentally, the project is complex. 

A section of the transmission line inside the Mount Roland Regional Reserve so that needs a greenlight from the state parks authority, while the state Environmental Protection Authority (EPA) is putting it through an assessment process that is used for often large or complex projects, or those likely to generate a high level of public interest.

The plan is to use Lake Cethana as the lower storage and construct a new off-river upper storage on the plateau west of the lake, the EPBC referral says. 

The difficulty is that not only will native bush need to be cleared, but the way the lake works will change as well – elements which will require EPBC oversight. 

The referral says it will need to clear up to 335.5 hectares (ha) of native vegetation, wet and dry eucalypt forest and highland Poa grassland, and rare plants will need to be moved. 

Potential Tasmanian devil and spotted-tail quoll habitats will need to be cleared, and potentially acid forming material in spoil stockpile may be exposed.

Four flora and seven fauna species listed under the Tasmanian Threatened Species Protection Act are found in the area. 

While seven years seems like a long time to get to the early stages of planning – a development application has been submitted to the local council – the timeline Hydro Tasmania included in its referral shows that it’s taken a lot of work to get this far. 

Between 2019 and 2022 the company talked to communities and other stakeholders, and did pre-feasibility and feasibility studies.

It says these activities have since ramped up, although with revised engineering plans that sent it back to the drawing board with the EPBC.