South Australian Premier Steven Marshall and Deputy Prime Minister Barnaby Joyce have announced $15 million in funding for a business case to explore the idea.

BHP and Adelaide-based company Oz Minerals have backed the plan, saying it would make their operations “more sustainable”.

The governments say building a desalination plan would ease reliance on the Great Artesian Basin and the River Murray.

They also predict that if it gets the go-ahead, the desalination plant would create 8000 construction jobs and 6000 jobs once operational.

Marshall said the Northern Water Supply project had the potential to create “thousands of jobs throughout South Australia”.

“This project is a once-in-a-lifetime opportunity to secure a brighter future for South Australia and create jobs in an environmentally sustainable way,” Marshall said in a statement overnight.

BHP asset president Dr Jennifer Purdie said the plan would help continue copper production in the future.

“We are taking action to reduce water use across our operations, and partnering with others in the communities and creating opportunities for future investments and jobs.”

BHP operates the Olympic Dam copper, gold and uranium mine while Oz Minerals mines copper and gold at Carrapateena and Prominent Hill.