The delay, which was originally planned for this week was expected to be up to 25 gigalitres (GL).

WaterNSW says the delay could be for up to a month until around the end of February with current reportings suggesting that there is a 'good flow' coming into Burrendong Dam. Further inflows are in the process of being recorded and assessed following rainfall in other areas in the region.

WaterNSW is also monitoring a significant storm event in recent days that has generated good follow up flows in the Cudgegong River, which feeds into Burrendong's storage.

The Windamere transfer was one of the final measures in a drought response strategy that has involved gradually restricted access to users and suspending environmental releases and carryover, as unprecedented drought conditions impacted on dam inflows. The Macquarie River's long term annual average inflow is 1450GL - in the five months from July 1 it received just 5GL.

Other measures have included preparing to pump remnant storage once Burrendong's water level falls below 0%, as well as cutting flows to creeks in the lower reaches of the system.

Mid-Western Regional Council prepared residents for the possibility of moving to Level 3 water restrictions following the transfer.

A Council spokesperson said the situation will be assessed following a future transfer.

"The proposed Bulk Water Transfer from Windamere to Burrendong Dam will reduce dam levels which may trigger Council to implement Level 3 water restrictions," they said.

"At this stage Council will remain on Level 2 water restrictions until the transfer proceeds at which time Council will review dam levels and apply the necessary restrictions to safeguard water stocks."

The last bulk water transfer between the two dams occurred in January 2019, with the intended delivery of 35GL being stopped at 10GL after a rain event resulted in inflows to Burrendong.