A few hours’ drive north of Sydney, in the Upper Hunter region, is the Bylong Valley.

Known for its fertile pastures, dramatic scenery and underground water, it appears pristine and peaceful.

But a decade-long stoush over mining has rattled the few remaining residents here, who are now trying to defend a decision to reject a South-Korean mining project going ahead.

Utility giant KEPCO’s proposal to mine for coal in the valley was rejected by the NSW Independent Planning Commission (IPC) in September.

The company had already spent $115 million buying 13,000 hectares of land and around $400 million on the mining license for the 25-year project.

SBS

In January, KEPCO's board marked down the value of its mining rights in the valley from nearly $650 million to zero. KEPCO's local branch is still appealing the IPC's decision.

"It's just the absolute uncertainty,” Bylong Valley resident Vicky Cook told SBS News.

“If they go ahead our biggest fear is our water. Without water, we've got no farms.”

The IPC cited "problematical" greenhouse gas emissions and impacts on groundwater as some of its reasons for refusing the mine.

But the IPC says an administrative legal principle, known as the Hardman principle, prevents it from defending its own decision during the appeal process.

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The Bylong Valley Protection Alliance, led by Bylong farmer Phillip Kennedy, has been seeking to join the case to provide an opposing voice.

“I'm wondering when the governments in this country are going to stop treating Australia like a clearing sale - [it's] just sell, sell, sell,” Mr Kennedy said.

“If I ran my farm like they run their government I'd have nothing left in 10 years’ time."

KEPCO’s purchases in the valley preceded the local school shutting down and a community of 30 or so people dwindled to just a handful.

SBS

Graham Tanner – or Tag, as he’s known - has lived in Bylong for about 20 years. He says huge swathes of land are now sitting idle as the appeal process plays out.

“We’re fighting for our lives, we’re fighting for our business,” he said.

"If the mine goes ahead that's the end of us, you know, we've got a stranded asset. You'll never be able to sell out because who wants to live in a coal pit?"

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Many business owners in Rylstone and Kandos, the towns closest to Bylong, do want the mine to go ahead though.

"The proponent’s decision to appeal will give hope to many in nearby local communities that are keen to see the project proceed,” CEO of the NSW Minerals Council Stephen Galilee said in a statement.

The NSW Department of Planning and Environment has said the development is approvable, subject to stringent conditions.

But NSW Greens MP Abigail Boyd is calling on the government to end uncertainty in the valley and buy back the land.

"There is a real opportunity for the government to just acknowledge the writing on the wall; the future is not with coal in the Bylong Valley it's with farming,” she said.