New Cobar has been deemed a state significant development by the NSW government.

The complex involves amalgamation of the existing approved underground mines at the Chesney and Jubilee deposits, and development of underground workings at the Great Cobar and Gladstone deposits.

Aurelia is to spend $65 million to develop the underground mine at Great Cobar, which will provide 400 operational jobs in the central west NSW region and another 140 jobs during construction.

According to a pre-feasibility study done in January, a satellite mine based on initial mining at Great Cobar with a maiden 840,000 tonne ore reserve, could offset mining depletion at Peak.

Accessing the copper-rich Great Cobar deposit through decline and underground mining could deliver a total of 47,000 tonnes of copper and 61,000 ounces of gold.

The PFS also shows Great Cobar could deliver 2.3 million tonnes to Peak's process plant over five years, for production of high-quality copper gold concentrate and gold-silver doré.

Development will consist of two parallel declines to access Great Cobar from the New Cobar workings along with a surface exhaust shaft and underground primary ventilation fan.

Aurelia Metals CEO and managing director Dan Clifford said his team had done a great job in bringing the project online at a time when copper prices were collecting more than US$9000 per tonne.

"We are also excited by the fact Aurelia is one of the only producers in the region to bring a new copper deposit into production in just two years' time, a catalyst that will deliver significant value for our shareholders and stakeholders, in particular the communities where we operate," he said.

"We would like to acknowledge and thank the Cobar shire council, the Department of Planning and Environment and the NSW government, the traditional custodians of the land the Ngemba, Ngiyampaa, Wangaaypuwan and Wayilwan people and the local community for their support of this important project."