The decision to close comes as a result of reduced demand for energy and changing policy focusing on renewable energy generation. In June, the company initially proposed its plan to close Flinders operations in Port Augusta including Leigh Creek coal mine as well as Northern & Playford B power stations.
The decision has been made following conclusion of more than four years of detailed strategic review with an intention to seek viable economic solution for its continued operation.
Alinta Energy CEO Jeff Dimery earlier said: "During this period the company has incurred operating losses in the vicinity of $100 million whilst at the same time investing an additional $200 million to extend the operating life of the Flinders business."
The company now scheduled the Leigh Creek mine closure date on 17 November 2015 while the Port Augusta power stations, which are fed by coal sourced from Leigh Creek mine, are planned to be closed about 31 March 2016.
The company has allotted $75m in redundancy benefits for affected employees as a result of Flinders Operations closure.
Dimery added: "Our major focus continues to be on working closely to assist our people through this transition period.
"When we announced our intent to close Flinders Operations in June 2015, Alinta Energy committed over $3.5m in funding to provide a suite of transitional support services to our people.
"The allocation of this funding has been split between retraining and reskilling assistance, financial advisory services, career counselling, wellbeing and human resource support, as well as Transition Centres and other job opportunity services."
