It believes the December 31 deadline set for the gazetting of the final plan is far too soon, however.

Individual irrigators and the Tamworth Regional Council have pressed for the deadline for submissions to be extended.

Namoi Water executive officer John Clements told The Leader his members had no desire to place any possible Chaffey Dam augmentation upgrade at risk yesterday.

He was responding to claims by Peter Draper, the independent Member for Tamworth and the chair of the ministerial advisory panel on the Peel Valley Water Sharing Plan.

Mr Draper has said any significant delays in signing off on a water sharing plan for the valley could spell the end for the long-awaited Chaffey Dam augmentation upgrade.

Federal Climate Change Minister Penny Wong has indicated she wants the water sharing plan in place by the end of the year.

It is feared that if this deadline is not met, the Federal Government could walk away from its conditional funding commitment to the project.

That, in turn, would mean it was unlikely the augmentation upgrade would be carried out at the same time as the ongoing safety upgrade.

A failure to synchronise the two projects would add millions of dollars to the cost of the capacity increase from 62 gigalitres to 100 gigalitres.

State Water staff have told The Leader that unless a decision to begin the augmentation work was made before July 2010, it would be virtually impossible to do it in conjunction with the safety upgrade.

Mr Clements said the December 31 date for a sign-off on the plan was unrealistic as there were major questions and serious issues that had to be discussed.

His preferred date is late February.

Mr Clements said, however, that if this was likely to threaten the augmentation upgrade, it may be possible to achieve a result by early February.

He believes it should still be possible to have a final decision on Chaffey even if discussions continue into February.

Namoi Water wrote to State Water Minister Phillip Costa on Monday asking for the gazettal date for the plan to be deferred to allow further discussion on the water sharing plan.