Exploratory work continues on Borumba pumped hydro dam

Expressions of interest for companies wanting to be involved in tunnelling of the $14.2bn Borumba Dam hydro project are open this week.

Qld Hydro is in the exploratory phase of transforming Borumba Dam into a pumped hydro powerhouse. Picture: Christine Schindler

The proposed $14.2bn Borumba pumped hydro dam is moving along in leaps and bounds, with Qld Hydro releasing exploratory works for tunnelling packages to qualified contractors.

The game-changing, 2000MW Borumba pumped hydro project would transform the Mary Valley into a major hub of Queensland electricity. The project, however, has been greeted locally with mixed feelings, particularly with the news of associated powerline infrastructure.

While initial exploratory ground works started in July 2023, Qld Hydro is now looking for expressions of interest from qualified contractors for the underground exploratory works, using the blast and drilling method to form a D-shaped tunnel and determining the location of the powerhouse cavern, planned to be 400m underground.

How Qld’s renewable energy future will affect you and your bills.

Map of Borumba Dam pumped hydro project.

The tunnel works include the required environmental approvals and would determine the exact location of the powerhouse cavern, and once passed would give the final green light for the project.

The proposed cavern, housing six reversible 330MW turbine pumps, is expected to be built also using the blast and drill method as means to excavate the soil and rock.

The cavern is estimated to be roughly the size of the Gabba stadium in Brisbane (250m long, 35m wide, and 60m high) and will have a further two tunnels for water flowing between the upper and lower reservoirs.

During the exploratory works phase, the tunnel will be used as a way to investigate what lies beneath the landscape surrounding the dam.

Once environmental and other approvals are complete, the tunnel will become a permanent cable tunnel used to access the cavern.

What is pumped hydro and how will it change Borumba Dam?

Timeline of Borumba Dam pumped hydro project.

“This tunnelling will compliment surface geological investigations, which together will provide a detailed understanding of ground conditions to inform detailed design of the project and how it is best delivered,” a statement from Qld Minister for Energy and Renewables Mick de Brenni said.

“The project is set to inject tens of millions into the regional economy, and deliver 2000 jobs during construction.”

The Queensland government has identified pumped hydro as a reliable renewable energy source in transitioning away from fossil fuels despite calls for a senate inquiry from communities on the front lines of the infrastructure and political opposition, particularly the Nationals.

Department of Energy and Public Works has said it would be the “biggest single investment in Queensland’s energy infrastructure in decades”.

The Queensland government has identified pumped hydro as a reliable renewable energy source in transitioning away from fossil fuels despite calls for a senate inquiry from communities on the front lines of the infrastructure and political opposition, particularly the Nationals, who want more research into the potential of nuclear power.

“As the cornerstone of the Queensland Energy and Jobs Plan, our pumped hydro projects will ensure Queensland remains on track to meeting its renewable energy targets, while ensuring we can continue to put ongoing downward pressure on electricity bills for years to come,” Mr de Brenni said.

Queensland Hydro CEO Kieran Cusack said they were excited to release the first major package of works since a series of industry events throughout June and July 2023.

“Queensland Hydro will work with the successful contractor to maximise opportunities for local and Indigenous businesses and workers to be prepared for, and access opportunities on the exploratory works program,” he said.

The tunnel drilling packages are scheduled in two phases, and prospective, suitable and qualified suppliers are encouraged to apply by December 4, 2023. If suppliers meet the eligibility criteria they will be short-listed and will need to submit a Request for Proposal, opening in February 2024.

Public comment on the referral of the project as part of the Environment Protection and Biodiversity Conservation Act is currently open until November 15, 2023 and can be made by following the link here.