Environmental issues


Macquarie Valley environmental water

brown water and grass in foreground with blue sky in background

Macquarie Marshes Nature Reserve 2010, showing vegetation response to environmental water flow following drought. Photo: Neal Foster.

The Macquarie River catchment covers 75,000 square kilometres, extending from the Blue Mountains to the Darling Riverine Plains. North of Warren, the Macquarie River spills into the iconic Macquarie Marshes, which extend over 100 km. Downstream of the Macquarie Marshes, the Macquarie River re-forms and flows to the Barwon River.

Environmental water delivery focus

The Macquarie Marshes are the catchment’s largest wetland system and the main focus of managed environmental water releases. The Marshes include a range of wetlands from semi-permanent marshes and lagoons to ephemeral wetlands that are only inundated by the largest floods.

Macquarie Marshes Nature Reserve and parts of the privately owned properties ‘Wilgara and 'U-Block’ are listed under the Convention on Wetlands of International Importance (the Ramsar Convention). More than 500 cultural heritage sites are recorded in the Macquarie Marshes, the traditional country of the Wailwan people.

Environmental water can also target:

  • Cudgegong and Macquarie River channels, for in-channel environmental benefits and to ‘drown out’ weirs to allow fish passage
  • the unregulated lower Macquarie River downstream of the Marshes
  • the distributary creek systems north-west of the Macquarie River, including Crooked, Duck, Marra and Gunningbar creeks.

View a map showing the location of environmental watering areas in the Macquarie Valley (Macquarie2013.pdf, 377 KB).

Benefits of environmental water

Environmental watering in the Macquarie catchment supports:

  • wetland vegetation communities, including river red gum, reed beds, water couch meadows, mixed marsh, river cooba, black box and coolibah
  • habitat for waterbird species that nest in colonies, including egrets, herons, cormorants, spoonbills, ibis and darter (the Marshes have supported some of the largest waterbird breeding events in Australia’s recorded history)
  • habitat for other waterbirds, including terns, ducks, swans, grebes, bitterns and stilts
  • summer harbour for various migratory wader species, including godwits, sandpipers and Latham’s snipe
  • habitat and opportunities for breeding and movement of vulnerable native fish, including Murray cod and silver perch.

Environmental Water Advisory Group

The Macquarie and Cudgegong Environmental Flows Reference Group advises OEH on planning for and delivering environmental water through the water season.


Environmental water management is supported by:

Page last updated: 08 December 2014