Environmental issues


Gwydir Valley environmental water

water in foreground with grass in centre and sky at top and birds in flight

Lower Gingham watercourse inundated, autumn 2012. Photo: Daryl Albertson, OEH.

The Gwydir catchment covers 26,596 square kilometres, extending from the northern tablelands to the northern plains where it joins the Barwon River.

Managed environmental water is focused on the floodplain area west of Moree where the Gwydir River branches into three main systems:

  • Gingham watercourse
  • Lower Gwydir (Big Leather) watercourses
  • Mehi, Mallowa and Moomin systems (south).

These areas contain a mosaic of wetland types from semi-permanent marshes and waterholes to floodplain woodlands which are only inundated during large floods.

Four wetlands in the Gwydir Valley are listed under the Convention on Wetlands of International Importance (the Ramsar Convention):

View a map showing the location of environmental watering areas in the Gwydir valley (Gwydirmap2013.pdf, 320KB).

The Gwydir wetlands are the Country of the local Gomeroi Aboriginal people, home of their heritage and important cultural sites. Over 160 cultural heritage sites have been recorded in the wetlands, including burial sites, scarred trees and stone artefacts. These wetlands were also known as a place of bountiful wild harvests.

Benefits of environmental water

Environmental water in the Gwydir Valley supports:

  • wetland vegetation, including river red gum forests, river cooba, water couch marsh, marsh club-rush sedgeland and common reeds
  • critical breeding and feeding habitat for colonial nesting waterbirds, such as egrets, herons, cormorants, spoonbills, ibis and darters
  • critical habitat for other waterbirds, including ducks, swans, grebes, coots and swamphens
  • habitat for migratory bird species listed under international agreements, including the barn swallow, black tern, Caspian tern, cattle egret and common tern
  • habitat for native fish breeding and recruitment, including several threatened native fish species, such as silver perch, olive perchlet, purple spotted gudgeon and eel-tailed catfish
  • the state’s largest stand of marsh club-rush sedgeland, listed as critically endangered under the NSW Threatened Species Conservation Act 1995.

Environmental Water Advisory Group

The Gwydir Environmental Contingency Allowance Operations Advisory Committee (ECAOAC) advises OEH on managing environmental water in the Gwydir. The ECAOAC provides advice on the annual environmental watering plan and on specific managed environmental water releases during the year. The committee is chaired by the Border Rivers-Gwydir Catchment Management Authority.


OEH manages environmental water in the Gwydir catchment in partnership with:


Environmental water planning is supported by the following key documents and plans:

Reports on environmental water use

Environmental water use for 2013-14 is reported in Environmental water use in NSW: Outcomes 2013-14, which outlines environmental water scenarios in detail.

Page last updated: 04 February 2015