Plans for a pumped hydro development west of the Blue Mountains have alarmed local Indigenous communities about the impacts on a culturally important mountain.
Energy Australia wants to build and operate a pumped hydro dam on Mount Walker at Lake Lyell near Lithgow.
Pumped hydro acts like a giant battery by moving water uphill during the day when solar and renewable energy is plentiful and releasing it downhill again through a turbine when that energy is needed.
The company argues the technology is needed for the renewable energy transition and to smooth out the peaks and troughs in energy supply that will become more of a problem as more wind and solar energy infrastructure is built.
However, plans for a large concrete reservoir along the ridge line of Mount Walker have residents worried about a popular recreation spot and sparked concern among local Indigenous communities.
'It takes away a piece of our identity'
Local Wiradjuri man Adrian Williams said Mount Walker's vantage point as one of the highest peaks in the district made it a culturally important site for traditional men's business.
"If anybody was coming through here and set up camp you would see within 20 to 30 kilometres if a campfire went up we would know if someone was moving through the area," he said.
Energy Australia's current concept design includes a 4.4-gigalitre concrete reservoir with walls up to 40 metres high on Mount Walker.
Mr Williams said it would destroy the cultural and environmentally significant site.
"It's gonna be knocking down a heap of trees, it's going to alter the landscape, and it's going to alter the energy of the area," he said.
Mr Williams said the prospect of losing an important cultural site was distressing.
"Every time something gets lost it takes away a piece of our identity, it takes away a piece of us," he said.
Lake Lyell was built in 1982 to supply water to the local coal-fired power stations, but it has also become a popular camping and fishing spot for the local community and visiting tourists.
Residents have concerns about an "eyesore" on Mount Walker and the impact of a potential power station on the dam's recreational features.
Energy Australia said the water level of the lake would deviate by up to 2 metres while the pumped hydro dam was in operation.
Rob White from the Concerned Lithgow Community Group believes the concrete dam on Mount Walker and the constant fluctuation in dam height would ruin the popular tourist spot, and impact on local land values.
"It's going to ruin the lake from a camping perspective, in that you'll go to bed at night and you'll wake up in the morning with your boat high and dry, sitting in mud," he said.
Storage needed
Energy Australia said the project would power 150,000 homes for about eight hours before needing to be refilled.
The company's head of portfolio delivery, Daniel Nugent, said it was important to have long-duration storage in the energy grid as more wind and solar energy was built.
"That's where we think pumped hydro can have a role ... we think we need a range of storage technologies to deliver this transition [to net-zero]," he said.
Mr Nugent said the project was still being assessed but cultural concerns would definitely be investigated.
"So Aboriginal cultural and heritage aspects will absolutely be fully considered," he said.
