Member for Shellharbour Anna Watson demanded answers from the Department of Primary Industries last week, saying the yet-to-be-formed estuary management committee was like the legend of the Loch Ness monster.

"[It is] frequently discussed but seldom seen," she said.

"The future of Lake Illawarra will become the care of all but the responsibility of no-one."

The state government chose to dissolve the Lake Illawarra Authority last year in favour of a committee run by Wollongong and Shellharbour city councils.

But despite a Wollongong council resolution on December 9 to defer the committee until the state government gave a firm commitment to ongoing financial support, Ms Watson said she had seen emails from councillors, seeking committee meeting details.

On December 10, Shellharbour council accepted the restructure, though it disagreed with the decision to scrap the LIA.

Save Lake Illawarra Action Group chairman Col Wilton said the process should not be allowed to drag on.

"The consequences of that could be that maintenance work won't be done," he said.

He believed a failure by the department to provide Wollongong council with enough information on the assets it would need to take on was the reason for the delay.

However, a department spokesman said the information had been provided, but the council had not responded.

A Wollongong council spokesman said a report would be brought to its April meeting, outlining the options for a committee and the financial implications.

"In the meantime, council officers continue to work with staff from Shellharbour City Council and relevant state government agencies to manage the operational details of the transitional arrangements," the spokesman said.

The LIA will wrap up its final projects this week.

The department spokesman said while some routine maintenance would continue, it would not be provided indefinitely.