Authorities are providing plenty of technical detail on how they will build the world’s largest pumped hydro plant south west of Gympie, but details of the environmental, safety and economic impacts are harder to find.
Experts in the Mary River catchment are calling for more detail on the environmental impacts, safety risks and economic case for the proposed $14 billion dollar Borumba Pumped Hydro project (BPH).
While local business and all sides of government (including the Greens) are broadly in favour, some local scientists, renewable energy experts and affected landholders say they have unanswered questions.
Save the Mary River Coordinating Group spokeswoman and affected landholder, Glenda Pickersgill, says while there has been community consultation, ‘we’ve seen zip documentation’.
‘We want to see the business case, the cost-benefit analysis and the comparison with the latest battery technology and other alternatives’, Ms Pickersgill said.
Queensland Energy Minister Mick de Brenni told ABC’s 7.30 Report the government had closely considered the alternatives.
‘We’ve worked for a number of years considering all these options and pumped hydro energy storage is the proven technology that will enable us to reach our renewable energy targets,’ he said.
The Queensland Government says the project, extending the existing Borumba Dam near the small town of Imbil, is a necessary part of its plan to transition to zero carbon emissions by 2050.
The 2-gigawatt project involves building a new, higher dam wall to hold five times more water in the existing Borumba Dam, demolishing the existing dam wall and building a new upper reservoir with a dam wall and a tunnel for pumping water between the two dams to generate electricity with turbines.

How the Borumba Pumped Hydro project will work
Business is positive
Mary Valley Chamber of Commerce President, Janelle Parker, is excited about the project, which she says will bring ‘short term pain for long term gain’.
Ms Parker says there are significant opportunities for business growth, new infrastructure and ecotourism supported by the BPH.
Imbil Fishing and Outdoors owner Graeme Rummler, says while there are ‘so many questions and not as many answers’, he takes the long view.
‘I think the new dam will be good for everyone. More surface area for fishing, sailing and more room for fingerlings. If they stock the new dam with fish, there will be more fishing.
‘It’s going to be good for the town. It’s been so quiet for so long. Take pictures now, because it won’t be like this forever.’

Mary Valley Traders owner Jo Robey is positive about BPH
Jo Robey, who owns Mary Valley Traders with husband Charlie, says the project will put Imbil on the map and increase recreational access to the dams.
‘Access to Borumba Dam is limited with one road that terminates at Borumba Dam. New roads to the existing and new dams could increase the public’s access,’ Ms Robey said.
She believes the project will bring multiple boat-ramps (there’s currently one) and trails for walking and mountain biking and a lower dam wall visitors can walk on.
‘I am excited. Traveston Dam was not done right and there’s an opportunity to do this right.’
Gympie Councillor, Bob Fredman, is advocating for best outcomes for the Mary Valley. Top of his list is extending the Imbil Rail Trail from Amamoor to Imbil which he says ‘would benefit all of the Mary Valley, not just Imbil’.
The former chief engineer for Gympie Council, Cr Fredman, believes the BPH engineering is ‘sound’ but questions whether the ‘phenomenal cost’ is justified. He’s pragmatic, saying ‘spending this amount of money has got to be good for the Mary Valley’.

Gympie Regional Councillor Bob Fredman
‘If we have to have it, let’s make the most of this opportunity.’
Queensland Hydro (QH), the entity delivering the BPH, is considering sweeteners for affected communities, including:
- new and upgraded local roads and bridges
- extension of the existing Rail Trail
- upgrade of the Imbil Rail Heritage Park and the old rail bridge
- new workforce accommodation
- sporting fields and recreational infrastructure
- walking and biking trails
- new boat ramps, carparks and camping areas close to the dams.
Queensland Hydro confirmed that during the exploratory phase, Bella Creek, Yielo and Borgan roads will be upgraded. Temporary construction camps on state government and QH owned land will accommodate workers for the time being. Access routes to the main works are yet to be determined.
Grave concerns
Local scientist and water modelling expert, Steve Burgess, has worked on water planning for the Mary River Catchment Coordinating Committee (MRCCC) since 2007 and with the state government to improve the Mary Basin Water Plan.
Mr Burgess says he has ‘grave concerns’ about the BPH project because of the scale and pace at which it is proceeding.
The new upper reservoir would be over one and half times the size of the existing Borumba Dam. The total capacity of the reservoirs in the completed project would be 1.8 times the capacity of proposed Traveston Dam. The generator cavern, blasted out of solid rock 400 metres underground, would be the height of an 18 storey building.
Queensland Hydro plans for BPH to be operating by 2030. This tracks with the Queensland Government’s plan to transition to 50 per cent renewable energy by 2030 and hold a ‘climate positive’ Olympics in 2032.
Mr Burgess says the MRCCC does not support or oppose BPH but uses its role on the Stakeholder Reference Committee to achieve best possible outcomes for the Mary River and the communities it supports.
Mr Burgess says people may not realise the risks a project of this scale and complexity carries.
‘I am not against pumped hydro at smaller scale, but there is no project of this size on the planet and it’s going ahead at breakneck speed.’ His concerns include:
- the potential impact on water quality, flora and fauna of turbidity and sediment in the expanded Borumba Dam and the river downstream caused by a massive pump system continuously circulating water;
- the complexity and timing of the (yet to be done) Dam Failure Impact Assessment required before the project starts to accurately assess the risks to people living downstream, particularly in Imbil;
- the lack of a formal analysis showing BPH will achieve the overall decarbonisation goal, taking into account its whole-of-life embodied carbon costs and methane off gassing from the breakdown of organic matter in the dams.
On a positive note, Mr Burgess said the potential for extra water being released as environmental flows in the Mary River and tributaries could be a plus ‘because the Mary River is in trouble’.
Overall, in advice to the MRCCC submitted in August, Mr Burgess said the project was a ‘leap into the unknown’.
‘The Mary River Catchment has never seen a proposal for water and energy infrastructure of anything remotely approaching the scale and complexity of this project,’ he said.
‘The significant financial, engineering and environmental risks are coupled with an undue haste to see this project operational within an unlikely timeframe.’

Queensland Hydro CEO Kieran Cusack
Asked if there was a formal analysis showing the BPH would achieve the overall decarbonisation goal, Queensland Hydro CEO Kieran Cusack said QH’s two projects (Borumba and Pioneer-Burdekin outside Mackay) were playing a critical role in helping meet the Queensland Government’s renewable energy targets.
Threatened species affected
On the environment front, Queensland Hydro’s Referral Report to the Federal Department of Climate Change, Energy, Environment and Water, identifies threatened flora and fauna in the BPH project footprint. It details QH’s plans to avoid and mitigate impacts during the exploratory phase.

Glossy Black Cockatoo feeding. IMAGE Birdlife Australia
This report is required under the Environment Protection and Biodiversity Conservation Act. It’s called the EPBC Report and is where the most detail of environmental impacts of the BPH project can be found. A separate referral report will be provided on the main works.
The EPBC Report lists threated flora and fauna in the BPH project area including the Macadamia Nut (vulnerable) and Scrub Turpentine (critically endangered), Glossy Black Cockatoo (vulnerable), Koala (endangered), Mary River Turtle (endangered), Lungfish (vulnerable) and Spotted Tail Quoll (endangered).
The report lists extensive measures to reduce the impact on flora and fauna while acknowledging significant habitat loss and displacement, injury and death of aquatic and terrestrial fauna are a risk.

Land and valleys near the proposed project site
Queensland Hydro CEO Kieran Cusack said the BPH project required state and federal environmental and planning approvals for the exploratory and main works requiring it to assess:
- the current environment in the project area
- potential environmental, social and economic impacts of the project
- measures to avoid, minimise, mitigate and/or offset those potential impacts.
Strongest opposition is to transmission lines
The strongest resistance to the BPH is coming from hundreds of landholders whose properties are affected by a proposed corridor of powerlines connecting the BPH to the main electricity grid.
Powerlink says the recommended powerline corridors from the BPH site north to Woolooga (north west of Gympie) and south west to Halys substation (west of Yarraman) will have the least overall impact and landholders will be fairly compensated.
Glenda Pickersgilll has a property affected by the proposed powerlines and says Powerlink has ‘no social licence’ and that many affected landholders will lock their gates.

Lock the gates signs along the proposed powerline corridor
A scientist and Mary Valley local since 1985, Ms Pickersgill was involved in the campaign to stop Traveston Dam. She owns two properties in the Borumba Pumped Hydro area, has a background working on environmental impacts of mining and brings EIS expertise to the discussion.
She is concerned about the lack of a Dam Failure Impact Assessment on the BPH. One of her Mary Valley properties already floods after heavy rain ‘so if a dam failed my property might be completely underwater’.
Ms Pickersgill is also worried about the possible impact on the quality and quantity of water in the Mary River downstream of the BPH project.
‘It’s important that the right quality and quantity of water flushes through, for the health of the Mary River and the RAMSAR wetlands of the Great Sandy Strait and the life cycles of flora and fauna.’
Traveston Dam legacy
Mary Valley Chamber of Commerce President Janelle Parker believes the community may have some leftover hesitancy about BPH because of the Traveston Dam experience.
‘Some people see the project through the filter of Traveston Dam,’ Ms Parker said.
‘There are people who sit in a purely environmental strata, economic strata or social strata.
‘There needs to be a meeting of the twain.’
Do the economics stack up?
One renewable energy expert says the economics are not feasible. David Leitch, is a principal at ITK, specialising in analysis of electricity, gas and decarbonisation.
In Renew Economy, a web-site focusing on green energy transition, Mr Leitch estimates the cost of BPH will be double the estimated $14 billion and that batteries would be cheaper.
On all these issues and more, Mary Valley locals may soon have more opportunities to chat directly with Queensland Hydro.
Asked about a rumour that the entity has signed a lease in Imbil, QH confirmed it will open an office in Imbil ‘in the near future’.

Gate to upper reservoir site
Want to know more?
- For info on Community Information Sessions go to https://qldhydro.com.au/
- Referral Report to the Environment Protection and Biodiversity Conservation www.epbcpublicportal.awe.gov.au
- Mary River Catchment Coordinating Committee https://mrccc.org.au/