Glencore's Glendell mine refused: Glencore hasn't ruled out an appeal as opponents hail refusal as a win

The IPC ruled the project would have "significant, irreversible and unjustified impacts on the historic heritage values of the Ravensworth Homestead complex" - a thumping win in the eyes heritage, climate and cultural activists.

Lock the Gate NSW coordinator Nic Clyde said it's a decision consistent with reconciliation.

"I was utterly convinced this was an immensely important site both for NSW's colonial heritage but importantly for the Wonnarua people," he said.

"It's the right call, those values clearly outweigh any value that could have been accrued from coal mining, and that's before you even start to look at climate issues.

"This needs to become a turning point in the history of our state where we reckon with the history of the settlement of NSW and as a community we place some value on understanding that history and coming to terms with how this country was settled and the need to reach a treaty with Aboriginal people."

Ravensworth Homestead, which is made up of colonial buildings and gardens in the middle of the proposed mine site, has cultural and historic significance that harks back to 1825.

Colonial records show a series of attacks and counter-attacks between Aboriginal people and settlers at the homestead and the adjoining Lethbridge Estate.

The main house would have had to be relocated for Glencore's project to proceed, which the commission found "would constitute a significant loss to future generations" - arguing the site "is not suitable for development" and "is not in the public interest".

Glencore hasn't ruled out an appeal, with a spokesman telling the Newcastle Herald it's extremely disappointed with the IPC's decision.

"It is particularly disheartening considering that Glencore has invested more than six years and $25 million in studies, as well as consulting with the community to provide a viable and environmentally sustainable project," he said.

"The project would have provided jobs for up to 600 people and ongoing support for 350 businesses in the Hunter region.

"We will carefully review the IPC's determination and statement of reasons and then decide if any further course of action is required."

The Continued Operations Project would have extended the life of the mine until approximately 2044, resulting in the extraction of an additional 140 million tonnes of coal.

NSW Minerals Council chief executive Stephen Galilee said the decision jeopardises hundreds of jobs and half-a-billion dollars in investment.

"The ongoing ability of the IPC to freelance planning decisions is of great concern," he said.

"The NSW government has left the economic future of regional communities to the mercy of an unelected and unaccountable body, with no obligation to abide by any of the policies of the elected government of the day."

In reaching its decision, the panel, made up of chair Dianne Leeson, Professor Snow Barlow and Adrian Pilton, received 899 written submissions, including 282 objections, 580 in support and 24 neutral submissions, and a further 13 submissions in response to specific heritage materials.

The commission acknowledged the project would have benefits and that other key issues that go hand-in-hand with mining could have been appropriately managed if the "significant and irreversible" impacts to heritage could have been avoided.

Greens Senator David Shoebridge called the decision an "incredible win" for the Wonnarua people.

"At times this felt like an impossible challenge where all the power lay with a multibillion-dollar, multinational resource company that had the ear of the state and federal governments," he said.

"In the end, the most powerful weapon was truth, the truth about Frontier violence and massacres, and the truth about culture and history that came from the Wonnarua people."

The question that lies ahead is what, if anything, will happen to Ravensworth Homestead - given its clear heritage significance.

A Heritage NSW spokeswoman said it will recommend Ravensworth Homestead be added to the State Heritage Register.

"Listing of Ravensworth would protect the site's important heritage values," she said.

"The IPC's decision will ensure the homestead remains in situ.

"Ravensworth is a highly significant early colonial homestead in the Hunter region and tells an important story about early colonial history, including the frontier conflict and dispossession of Aboriginal people."

Two years ago, Mr Shoebridge, on behalf of the Plains Clan of the Wonnarua People, asked the federal government to declare the site as one of special significance to Aboriginal people - which was unsuccessful.

The Environmental Defenders Office represented Wonnarua Traditional Owners Scott Franks and Robert Lester in the matter, and managing lawyer Rana Koroglu said the project would have been devastating.

"We welcome the IPC decision, which recognises the project would have had unacceptable impacts on heritage and that its approval would have been contrary to the principles of ecologically sustainable development, particularly the principal of intergenerational equity," she said.

"Thanks to this decision, the priceless Wonnarua cultural heritage of the Ravensworth Estate, including its important associations with the Frontier Wars in the Hunter Valley - that was under threat from this proposal, will also be saved."

The NSW Independent Planning Commission has refused Glencore's bid to expand Glendell coal mine near Singleton.

The IPC deemed the project was "not in the public interest, despite its likely benefits", saying the mine would have "significant, irreversible and unjustified impacts on the historic heritage values of the Ravensworth Homestead complex".

In reaching its decision, the panel, made up of chair Dianne Leeson, Professor Snow Barlow and Adrian Pilton, received 899 written submissions, including 282 objections, 580 in support and 24 neutral submissions, and a further 13 submissions in response to specific heritage materials.

Previously, experts told the commission that there are few homesteads of Ravensworth's nature nationally, and its removal would strip it of its cultural and historic significance.

Colonial records show a series of attacks and counter-attacks between Aboriginal people and settlers occurred at the estate and the adjoining Lethbridge Estate between 1825 and 1826.

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