Landholders along the Murrumbidgee River and its tributaries are advised to be ready for a possible environmental water release later this month or next month.
This release will be subject to suitable rainfalls and catchment conditions.
If it proceeds, the release will target a depth of 4.9 metres (about 27,500 megalitres per day) at Wagga.
This is well below the minor flood level of 7.3 metres and one metre lower than environmental water release levels in 2011.
NSW Office of Environment and Heritage (OEH) senior environmental water manager James Maguire said the event was a top priority in the annual environmental water plan for the Murrumbidgee.
"This watering event is aimed at filling hundreds of wetlands along the river system, particularly between Narrandera and Carrathool, which remained dry throughout the millennium drought from 2001 to 2010," Mr Maguire said.
"Bringing water into these currently dry wetlands is essential for the survival of aquatic vegetation that was once widespread throughout the river system.
"If the wetlands stay dry for too long, aquatic vegetation really struggles to come back and may disappear from local river reaches.
"Losing vegetation can be detrimental for frogs such as southern bell frog and birds like Australasian bitterns, which rely on wetland areas for habitat and foraging.
"The environmental flow is also critically important for native fish, which require higher flow levels to be able to move within the length of the river."
Mr Maguire said the OEH, on behalf of the Murrumbidgee Environmental Water Advisory Group, was consulting with communities along the river and received support for this flow on a trial basis.
"The community consultation process and co-operation with other agencies and river operators has been an important part of planning this event," he said.
"The state government has been working closely with the Commonwealth Environmental Water Office, which is contributing environmental water.
"All agencies have worked to minimise the potential for unforeseen impacts."
Updates on the event will be posted at www.environment.nsw.gov.au.
Adjoining landholders will be contacted regularly leading up to the event should rainfall and other conditions be favourable for it proceed.