The annual plan includes the delivery of 30,000 megalitres (ML) of NSW and Commonwealth environmental water to support the Macquarie River and floodplains downstream of Burrendong Dam including the core vegetation communities of the iconic Macquarie Marshes.

To complement this release, 9337 ML of environmental water has been made available for additional flow variability for native fish should the right conditions arise.

A further 5000 ML is currently being released to the Eastern Macquarie Marshes to piggyback off a recent stock and domestic flow and rainfall events.

This will result in floodplain and wetland inundation in this part of the Macquarie Marshes, including the Wilgara Wetlands part of the Macquarie Marshes Ramsar site.

To provide the best possible conditions for native fish like Murray cod, trout cod and silver perch, the main flow will commence upon a suitably-sized natural flow occurring in the river, or by early-October 2014, whichever happens first.

This flow will be a collaborative delivery of general security licenced water and allowances between the NSW government and the Commonwealth Environmental Water Holder.

The details of the releases were planned with the assistance of the Macquarie and Cudgegong Environmental Flows Reference Group, a multi-stakeholder group whose members include representatives from landholder, industry, conservation, Aboriginal community and government groups.

NSW Office of Environment and Heritage Senior Wetland and Rivers Conservation Officer, Tim Hosking said that the release would help support the maintenance of ecosystems of the river system.

"Like all general security water users, we're facing a lean year ahead but with input from the Environmental Flows Reference Group, we have planned for drier conditions and limited environmental water available to support the ecosystems of the catchment including the core of the Macquarie Marshes and native fish.

"We're hoping for rain, so that we have greater protection against drought but in the meantime, we'll do the best we can with our water allocation to maintain resilience across the catchment.

"We hope this environmental water flow will value-add to the recent commissioning of the Burrendong cold water pollution mitigation curtain by State Water, which will mean warmer, more oxygenated river flows in spring and summer.

The Environmental Flows Reference Group was recently given a tour of the newly-commissioned curtain by State Water.

Hopefully the whole river ecosystem really kicks along this year," Mr Hosking said.

The Commonwealth Environmental Water Holder, David Papps said the delivery of 30,000 ML and the contingency available to provide further flows for native fish if conditions were right, would deliver multiple outcomes in the Macquarie catchment.

"The 30,000 ML will benefit native fish in the Macquarie River, and support a range of core wetland vegetation such as common reed beds and water couch meadows in the Macquarie Marshes," he said.

"In combination with the cold water pollution mitigation curtain, delivering flows in response to natural flow triggers and at a time when water temperatures are suitable, will also increase opportunities for native fish, which will help to create a competitive advantage over damaging invasive species like carp."

The remaining 25,000 ML of environmental water left in accounts will be carried over to meet environmental demands in 2015-16.

Further information on general environmental water management or for the particular environmental flow event can be found on the NSW OEH website at http://www.environment.nsw.gov.au/environmentalwater/envwatermacquarieupdate.htm or by contacting Tim Hosking at tim.hosking@environment.nsw.gov.au or 02 6883 5330.