A KOREAN government-backed mine proposal in the Upper Hunter is the new frontier in the clash between coal and agriculture after the shock Shenhua Watermark mine approval on the Liverpool Plains.

Kepco’s plan for a Bylong Valley mine with ‘‘significant’’ impacts on prime agricultural land and ‘‘highly productive groundwater’’ has united farmers, environmental groups and academics who oppose the project.

‘‘If I was advising the minerals industry, I would have told them a long time ago there are some projects you should leave alone because they’ll do you irreparable harm, and Watermark and Kepco are on that list,’’ said NSW Farmers mining spokesman Tim Duddy.

An Australia-first plan by Kepco to ‘‘re-create’’ 194 hectares of prime agricultural land that will be permanently destroyed if the Bylong mine is approved, by moving 1.5million cubic metres of soil to another location, has been ridiculed by critics, including Mr Duddy, and questioned by a NSW government panel over its lack of detail.

The project will also spell the end for Tarwyn Park, the property developed by Peter Andrews and hailed as the beacon for sustainable Australian land use in the future, which was sold to Kepco in early 2014 when Mr Andrews’ son, Stuart, gave up fighting the company because ‘‘they have the law on their side’’.

Kepco Electric Power Group Australia, a company 51per cent owned by the Korean government, paid $403million to Anglo American in 2010 for the exploration licence and coal asset, and expects to lodge an environmental impact statement for the project with the Department of Planning in coming weeks.

In January last year, company chief executive Jae Wan Chung said Kepco was confident of gaining approval, and ‘‘success will determine if the company pursues further projects in Australia’’.

Bylong Valley Protection Alliance’s Craig Shaw, whose property is affected by the project, said while community outrage had been focused on the Shenhua Watermark decision, the relative impacts of the Kepco mine on Bylong Valley would be even greater than the Watermark mine on the fertile Liverpool Plains.

The Kepco mine would disturb 2667hectares of land, with direct impacts on 401hectares of verified prime agricultural land; had already had an impact on 1933hectares of verified equine land, and would have significant impacts on ‘‘highly productive alluvial groundwater for decades’’, a NSW mining and petroleum gateway panel found in April last year.

‘‘If we’re going to make a stand in terms of whether we value agricultural land in this country, then it should be here,’’ Mr Shaw said.

Kepco’s decision to pay $403million for the exploration licence should not be used as a reason to approve the project, he said.

‘‘Why are we made to feel like we have to facilitate this because of what they paid? Why is it our problem?’’ Mr Shaw said.

The Kepco mine, proposed to extract 120million tonnes of coal over 29 years, would require double the water needed to operate the Watermark mine, figures supplied to the NSW Department of Planning showed.

But the NSW Office of Water and a NSW mining and petroleum gateway panel raised serious concerns about the availability of water for the Kepco mine, the significant impacts on groundwater, and the company’s plans if it was ordered to cease pumping water during dry conditions.

University of Newcastle academic Peter Stevens said Bylong Valley should not be mined.

 ‘‘It’s folly to mine the Bylong Valley given that the long-term prospects for that area to provide for human sustenance are far greater than anything that can be gained by a mine,’’ he said.

Retired Professor David Mitchell, who specialised in management of water resources, said open-cut coal mining over decades caused ‘‘irreparable’’ damage.

‘‘If there are huge benefits to be gained and those benefits are widespread, then you can make an argument for it, but if the benefits are to be gained by a few people, then it’s right for people to question it,’’ he said.

A Kepco spokesman said the project had been carefully designed to avoid impacts on the most productive alluvial lands in Bylong valley.

The proposal would disturb less than 2 per cent of the valley floor and the company was confident of being able to effectively manage impacts on the community and environment, including groundwater impacts, the spokesman said.