The Borumba Pumped Hydro project operator is reassuring local residents that the new upper dam and enlarged Lake Borumba dam will be safe and built to withstand ‘extreme and prolonged weather events’.
Queensland Hydro was responding to concerns from residents and one dam expert that a dam Failure Impact Assessment (FIA) was not conducted before the state government decided to proceed with the project (yet to be approved by the federal government).
Landholder and cattle grazier Glenda Pickersgill said her acreage on the Mary River between Kandanga and Amamoor flooded regularly.
Grazier Glenda Pickersgill at her property on the Mary River. PHOTO: Brea Martin
Ms Pickersgill said a failure in Lake Borumba’s existing dam wall would have a ‘catastrophic effect’ on her property and the local community.
She said the current seqwater Emergency Action Plan (which says the risk of dam failure is ‘very low’) modelled communities downstream of Lake Borumba, as far as Gympie, being flooded within hours of a dam wall failure.
‘The existing Borumba Dam wall does not meet the Australia National Committee On Large Dams (ANCOLD) safety guidelines and dams are not built to last forever,’ Ms Pickersgill said.
‘That’s why it is being demolished and rebuilt as part of the Borumba Pumped Hydro energy storage project.
‘The Mary River Catchment has never seen a proposal for a piece of water and civic infrastructure even remotely approaching the sheer scale and complexity of the Borumba Pumped Hydro project.
‘There are many unknowns and significant engineering risks,’ Ms Pickersgill said.
‘Risk of engineering failure’
Mary Valley resident Steve Burgess has a background in hydrology and said a Failure Impact Assessment should have been done at the outset because Borumba Pumped Hydro carried a ‘huge risk of engineering failure and flooding.’
Mary River resident Steve Burgess at Lake Borumba. PHOTO: Brea Martin
‘Nowhere in Australia is a plant like this being built in this geological setting on top of a mountain,’ Mr Burgess said.
‘There’s a proposed new upper reservoir twice the size of the current Borumba Dam. There’s a cascade of safety risks.’
Imbil is the closest town to the project and some residents expressed safety concerns to The Pineapple.
Mixed feelings in Imbil
Imbil resident Jade Lovejoy said she planned to leave town if the project was approved.
‘I came to the conclusion I wanted to get out of Imbil ASAP …as I don’t feel like being washed away if SHTF,’ she said.
Valda Nicoll lives on Yabba Creek Rd about seven kilometres from Lake Borumba and believes there should have been a dam Failure Impact Assessment before the project commenced.
(Queensland Hydro has said an FIA would be done as part of the Environmental Impact Assessment for the Main Works due in 2025.)
‘I feel that it is just outrageous they are powering ahead without these vital studies put in place first,’ Ms Nicoll said.
‘I’m not concerned about dam failure for my property, because we are elevated, but I’m concerned for families in the lower areas.’
Imbil resident Valda Nicholl. IMAGE: supplied
Some residents trust the engineering
Imbil resident and geographer Ian Stehbens, whose family have lived in Imbil for three generations, said he was not concerned about any failure of the dams built for Borumba Pumped Hydro.
‘I am not worried because I trust the engineering’, Mr Stehbens said. ‘I’m confident it won’t flood.
‘No dams have failed in Australia ever.’
Mary Valley Traders is a business near Lake Borumba. Owner Jo Robey said she was not worried about safety risks of Borumba Pumped Hydro.
‘The most important thing to remember is Yabba Creek already has a dam on Lake Borumba.
‘If the current wall failed, Imbil would be under water.
‘So it’s no different if new dams are built, except we will have totally new infrastructure,’ Ms Robey said.
The existing dam wall on Lake Borumba. PHOTO: Brea Martin
Operator says it will ensure safety
A spokesman for Queensland Hydro said there were regulatory and engineering requirements to ensure the safety of downstream communities and landholders.
‘Dams of this nature in Australia are required to be designed in accordance with strict requirements and standards to ensure they are able to withstand very extreme and prolonged weather events,’ the spokesman said.
Model of a pumped hydro plant. IMAGE Queensland Hydro
‘This includes requiring a number of site-specific assessments to inform the design and construction of the dams.
‘Once constructed, dams must also be operated in accordance with defined operating procedures and parameters informed by monitoring of upstream and downstream conditions and the current status and capacity of the dams.
‘These procedures ensure the dams are in a safe operating state at all times, even during extreme weather events.’
The spokesman said the dams constructed for Borumba Pumped Hydro would be ‘be extremely safe’.
Expert opinion
Veteran dam engineer Ken Pearce has 40 years of professional engineering experience and was involved in the design and construction of Wivenhoe, Splityard Creek, Boondooma and Kinchant dams.
He was Principal Engineer at the Queensland Water Resources Commission in the 90s when he says the government stopped establishing feasibility of major projects ‘up front’ in favour of the work being done by the project proponents.
Ken Pearce IMAGE: supplied
‘The new approach at Paradise Dam, which is being used on the Borumba Pumped Hydro is fundamentally flawed’ Mr Pearce said.
‘They built a lemon with Paradise Dam: you could hardly expect them to do otherwise at Borumba.’
‘Paradise Dam came close to failing with potentially devastating results for Bundaberg during the 2013 flooding.’
Mr Pearce believes the Failure Impact Assessment of Borumba Pumped Hydro should have been done by now.
‘Very large scale water infrastructure projects pose very significant risks,’ he said.
Engineering Australia says safety risk very low
Dr John Macintosh is a consulting engineer with over 40 years of experience in water engineering. He has worked on several dams, including hydropower and has prepared FIAs.
Speaking on behalf of Engineers Australia, Dr Macintosh said the safety risk of pumped hydro was very low.
Dr John Macintosh. IMAGE supplied
‘The biggest risk is a dam wall being overtopped, because water running over the top of the dam wall will take out the foundations and you lose the structure,’ Dr Macintosh said.
‘With pumped hydro you want to make darn sure the water is not going to overtop the upper dam wall if there is a whopping big storm,’ he said.
‘The operator can manage the upper dam so the water level remains well and truly below the dam wall with a clear margin for the worst possible storm.
Well controlled situation
‘It’s a very well controlled situation because the water level is created by pumping water to the upper dam.’
Dr Macintosh believes it’s appropriate for the Failure Impact Assessment to be conducted with the EIS for the Main Works down the track.
‘The FIA will look at the feasibility of the structure. Whether it’s done before or after the exploratory works, the outcome will be the same because the engineers will design for the findings of the FIA’.
‘Pumped hydro is a relatively new concept in Australia but it is not new technology and it’s using well established engineering capabilities.
‘My view is there is no reason for concern for personal safety in connection with this type of project,’ Dr Macintosh said.
Photo of Queensland Hydro sign at one of the gates to the project site. IMAGE: Vivienne Wynter
