Longwall extraction at the mine was previously expected to conclude in late June, with the recently approved new panel Longwall 10A targeting 1.9 million tonnes run of mine.

“This longwall panel would extend the life of the North Wambo Underground Mine by six months and provide continuity of operations with the South Bates Underground Mine,” the NSW Planning and Infrastructure Department said in its assessment report.

“The proposed longwall panel would be 2km long, with a 1,745m extraction length, 26m wide chain pillars, 253m wide extraction face and 2.6m extraction height.”

The modification only related to the underground workings of North Wambo with other approval conditions for the wider Wambo complex to remain unchanged.

Some additional subsidence-induced fracturing and “increased hydrological connectivity” was predicted from the additional panel.

However, these fell under existing Wambo consent requirements for management of such impacts with the new panel approved as a consequence.

Department of Planning and Environment resource assessments and compliance executive director Oliver Holm signed off on the approval on Friday.