A court has heard the "cumulative impacts" of a series of gas plants proposed to run data centres in the Southern Highlands are being ignored as a result of fragmented planning decisions.
Seven community members gave evidence at the site of the development in Moss Vale on Tuesday morning, kicking off a three-day hearing in the Land and Environment Court.
The court is considering developer Nakar Property's appeal of a refusal by Wingecarribee Shire Council for one of its projects on the site.
The application was for a 16-megawatt gas-fired power plant and battery storage system to power data centres.
Separately, the developer has secured approval for another gas-fired plant on the site, a 14MW facility, and is seeking state government approval for a third, 673MW plant.
More than 100 community members gathered on the site ahead of the Land and Environment Court hearing. (ABC Illawarra: Penny Burfitt)
A crowd of more than 100 community members, Land and Environment Court Commissioner Nicola Targett, and representatives for the council and the applicant gathered in an open field in Moss Vale for the first day of the hearing.
The first community member to address the court was Dane Shanahan, who introduced himself by his Gundungurra name, Mullyang.
The emerging knowledge-holder for the region's traditional landowners told the court his name meant "eagle" and, as he outlined his community's concerns about the project, two wedge-tailed eagles appeared in the sky above the open-air court.
After the proceedings, Mr Shanahan described the appearance of the birds as an "ancestral presence".
He was one of several speakers to urge the commissioner to consider the application for the 16MW facility in the broader context of the development.
"Each piece is being presented as small — each piece is being assessed on its own and no-one is looking at the whole," Mr Shanahan told the court.
The court is only assessing the appeal lodged by Nakar Property for the 16MW facility and battery, but Gabby Kent, who lives 1 kilometre from the proposed site, agreed with Mr Shanahan's argument.
"The planning processes may be separate, but the cumulative impacts to my family … and my community are not," she said.
Will McCarthy says the project needs to be looked at as a whole. (ABC Illawarra: Penny Burfitt)
Will McCarthy, whose home overlooks the development, echoed those sentiments.
"At some point the planning system needs to stand back at look at the development as a whole," he told the commissioner.
The court heard the applicant had submitted an amended plan for the development to speakers and parties ahead of the hearing.
That submission included changes such as painting exhaust stacks green to address visual amenity, and adding some onsite solar power generation.
Consultation challenged
Mr Shanahan told the court no Gundungurra people had been consulted as part of the development application's Aboriginal Heritage Assessment, despite the cultural significance of a waterway that would be cut off by the project.
"It is as significant to the Gundungurra as Genesis is to Christians," he said.
"The applicant has proposed to reshape an ancestral waterway without asking the people [whether] it will scar."
The power plant and battery would provide power to data centres on Cloud Carrier's Moss Vale site. (Supplied: Cloud Carrier)
Jacqueline Duc raised concerns about the health impacts of pollutants, telling the court carcinogens from gas power-plants had been linked to lung and childhood cancers.
She also raised concerns about the project being located within the Sydney water catchment, saying its tributaries eventually flowed into Warragamba Dam, which supplied 80 per cent of the city's drinking water.
The applicant's lawyer, James Smith, did not question any of the community speakers.
The court will hear from the applicant's attorney and the council's representative, Michael Staunton, in coming days.