Wollongong Coal, formerly Gujarat NRE, has lodged plans with the NSW Department of Planning and Infrastructure to allow it to mine 400 metres of "longwall six" at Russell Vale Colliery.

It has claimed that without approval, the mine would be forced into care and maintenance mode, putting hundreds of jobs at risk and making future operations unviable.

At Monday night's meeting, councillors passed without debate a submission outlining concerns at the proposed changes to what is called longwall panel A2 LW6.

"Council is concerned about the current configuration, length and orientation of proposed longwall panel A2 LW6, given that it remains unchanged, despite council's previous written concerns," the submission says.

Those concerns related to "any potential subsidence-related impacts" on several "special significance" coastal upland swamps.

The swamps are significant as they can support a number of tree species.

"In council's view, the current proposed 400-metre section of longwall panel A2 LW6 may result in subsidence-related impacts (such as surface or groundwater flow reduction/loss) which may adversely affect the upland swamps ... given that they overlie the proposed 400-metre section of longwall panel A2 LW6," the submission says.

Instead, the submission recommends the proposed 400-metre section be realigned to the other end of the longwall panel which is clear of these swamps.

The submission also expresses concern that other required works are five months overdue.

"Council is also concerned about the colliery's failure to complete the required Bellambi Gully Creek realignment and channelisation works by the required deadline of 31 December 2013," it says.

These works were required to reduce downstream flooding impacts on surrounding property.

"Council requests that NSW Planning and Infrastructure direct Wollongong Coal to commence the required Bellambi Creek Gully realignment and channelisation works as soon as possible."