Documents tabled in Parliament show senior finance bureaucrats requested off-stream storage data for a Native Dog Creek dam proposal in the same area in September last year.

Hunter Water provided the information that showed the dam footprint would be 998 hectares with a storage capacity of about 60per cent of the original Tillegra dam near Dungog.

Metropolitan Water and Hunter Water are working on a new Lower Hunter water plan after an independent assessment found the $477million original dam proposal was not in the public interest.

Premier Barry O’Farrell told a budget estimates hearing last year that his government would not build ‘‘Tillegra mark II’’.

But Finance and Services Minister Greg Pearce would not rule out yesterday the Native Dog Creek dam as an option for the water plan.

‘‘The planning principles for the [water plan] require the planning process to consider the full range of potential water supply and demand options,’’ he said in a statement. ‘‘Due process requires the necessary analysis to be considered on all options except for Labor’s previously proposed Tillegra dam.’’

He told Parliament the government was committed to a transparent process and it was ‘‘scare mongering’’ to suggest it would build ‘‘Tillegra dam’’.

Mr Pearce met with members of the No Tillegra Dam Group yesterday.

Group chairwoman Carol Pasenow said members appealed to Mr Pearce to make a public statement ruling out any dam at Tillegra, to give residents and landowners certainty.

‘‘It is the same area, the same river system, you can’t pretend it’s not a repeat of Tillegra,’’ she said.

Greens MP John Kaye said a Native Dog Creek dam would present the same problems for the environment and household water bills and "is just as unnecessary as Tillegra".

‘‘The O’Farrell government has allowed itself to be dragged into the same quagmire that badly damaged Labor in the Hunter,’’ Dr Kaye said.