Big-T Pumped Hydropower Energy Storage project

Status

EIS active

Jobs

350 (construction) + 10 (operational)

Investment

$1.3 billion

Project overview*

EIS statusEIS active
Description Development of a pumped hydropower energy storage project with the capacity to generate up to 400 megawatts (MW) of continuous electricity for 10 hours per day, and a battery energy storage system with a capacity of 200 megawatt hours (MWh)
Proponent Cressbrook Project Co Pty Ltd as Trustee for Big-T Unit Trust
Location/s

Approximately 45km north-east of Toowoomba.

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Local government/s Toowoomba Regional Council and Somerset Regional Council
Investment Up to $1.3 billion
Key features
  • new upper reservoir located on Mt Sevastopol
  • underground water conveyances and intake/outlet infrastructure connecting the water conveyances between the upper reservoir and existing Lake Cressbrook (lower reservoir)
  • underground power station cavern, housing two 200 megawatt reversible turbines and access tunnel
  • 15km underground double-circuit 275 kilovolt transmission line and a new switching station
  • evacuation and ventilation tunnel
  • upgrade of Sebastapool and Three Mile Roads and new 3km access road to the tunnel portals and lower intake
  • a battery energy storage system
Construction start date TBC
Jobs
  • 350 (construction)
  • 10 (operational)

* Project information supplied by proponent and subject to change.

Environmental impact statement (EIS) process

DateActivity
Currently Draft EIS being prepared by proponent.
17 April 2026 The Coordinator-General stated a new project declaration lapse date of 30 October 2028.
25 September 2024 The Coordinator-General stated a new project declaration lapse date of 30 April 2026.
20 April 2023 Terms of reference for an EIS (pdf_file 1.7 MB) released.
21 January 2023 to 22 February 2023 Draft terms of reference (pdf_file 2.4 MB) for EIS public consultation.
30 September 2022 Gazettal (pdf_file 225 KB) of 'coordinated project' declaration.
15 July 2022 Application, including final initial advice statement (pdf_file 8.3 MB), submitted.
22 March 2022 Australian Minister for the Environment decided the project is a ‘controlled action’.

A project that has the potential to have a significant impact on matters of national environmental significance is called a 'controlled action' and requires approval under the Environment Protection and Biodiversity Conservation Act 1999 (Cth).

Further information

Read more about the EIS process.

Last updated: 9 September 2026

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