Cr Vicki Curran raised the concerns at Monday night's meeting, originally urging the council to launch its own geotechnical investigation as the reserves near Windang Bridge and Oakland Village were washing away and creating hazards for residents and tourists.

However, other councillors objected to her motion due to the costs it would impose on ratepayers and suggested the government - as the lake's current authority - foot the bill.

The lake's management is in limbo after the NSW government scrapped the Lake Illawarra Authority last year.

In December, Wollongong councillors voted to defer making a decision on the proposed estuary management committee saying the government needed to make a firmer financial commitment.

They are due to reconsider this vote in April.

In her original motion, Cr Curran said thorough research into the causes of instability and erosion - including "sinkholes" which had formed on the reserve near the village - was urgently needed before it caused more damage.

Oaklands Village park manager Mark Lopez also spoke at the meeting and asked councillors to take action, as the current erosion near the park's reserve was "a lawsuit waiting to happen".

Other councillors agreed the management of the lake needed attention, but did not want the council to bear the costs.

Cr Chris Connor said the original motion was premature, as it was still unclear whether the government or the council would be responsible for managing the lake's foreshore.

Raising similar concerns, Greens councillor George Takacs suggested the council write to the relevant state government minister asking them to carry out the geotechnical work.

"We can't leave these residents in the lurch, so we need to write to the appropriate authority," Cr Takacs said.

He also said the erosion at Windang highlighted the burden the government had put on the council by dismantling the LIA.

Ann Martin agreed, saying the council was likely to face similar issues in the future and needed to lobby the government for more financial assistance.

Councillors voted unanimously to support Cr Takacs' motion.