A Hunter Valley farmer who waged a long and personal war against a coalmine expansion says her community can breathe again after approvals for the project lapsed.

Wendy Bowman steadfastly refused to sell her 182-hectare property near Camberwell to Yancoal and even changed her will to ensure the mining company wouldn’t be able to buy it after her death.

The grandmother’s decades-long battle won her the international Goldman Environmental Prize, which honours grassroots efforts to protect the planet.

The Environmental Defenders Office supported legal challenges against the Ashton southeast open-cut coalmine extension and says approval for the project lapsed on April 17.

Ms Bowman, who mobilised a community-wide campaign against the project, believes that’s the final nail in the project’s coffin.

In 2014, she won a landmark case in the NSW Land and Environment Court, which ruled the expansion could only proceed if Yancoal purchased her property. A subsequent appeal by the company failed.

“It’s all been worthwhile,” Ms Bowman said in a statement on Friday.

“The reason I was so determined was I wanted to protect our lovely village Camberwell and the water in Glennies Creek.

“I opposed the mine expansion right from the beginning because the village and the water were so important. I was thinking of everyone downstream who completely relies on that water. It was just so stupid – the whole project.”

She said the approval’s lapse was a tremendous relief for everybody.

“So many people have worked to help stop it. It’s marvellous to think we’ve stuck to it for so long and got there in the end,” Ms Bowman said.

The judges for the Goldman Environmental Prize said Ms Bowman rejected multimillion-dollar offers for her property after the vast majority of landholders in the proposed mining area sold up.

Given that more than half of the coal for the proposed mine lay beneath Ms Bowman’s property, her refusal to sell was a significant issue.

In a statement on Friday, Yancoal said it would continue mining operations at Ashton by extending underground operations into the adjoining Ravensworth underground mine.

“This is a practical and efficient proposal, given proximity to a resource that already has approval to be mined, as well as the availability of existing equipment and infrastructure.”

It said key components of existing approved underground operations at Ashton would remain unchanged, including the annual maximum coal production rate.

“Minor modifications to relevant government approvals will be required to enable Ashton to access the unmined Ravensworth underground mine coal resource and these are currently being progressed.”

Get all the latest Newcastle news, sport, entertainment, lifestyle, competitions and more delivered straight to your inbox with the Newcastle Weekly Daily Newsletter. Sign up here.