The Gwydir River Valley
The Gwydir River Valley contains diverse and natural environments that support domestic water use, agriculture, tourism and recreation, mining and the cultural values and practice of local Aboriginal Traditional Owners.
The principal wetland areas of the Gwydir River Valley targeted by environmental water are the lower Gwydir, Gingham Watercourse and Mallowa Wetlands.
The nationally significant Gwydir Wetlands, in the downstream reaches of the Gwydir River and Gingham Watercourse, below Moree and on the floodplain of the lower Gwydir River, are among the most extensive and significant semi-permanent wetlands in north-west New South Wales are a key asset in the Gwydir River Valley.
The Gingham and Lower Gwydir (Big Leather) watercourse form an inland terminal wetland delta system which contains the largest stand of the critically endangered marsh club-rush in New South Wales. The Gwydir River Valley overall is home to more than 60,000 hectares of wetland vegetation, providing habitat for rare, endangered, and vulnerable species including the Australian bittern, freshwater catfish, olive perchlet, and the painted snipe.
Four sites (comprising 823 hectares) in the lower Gwydir and Gingham are internationally recognised under the Ramsar Convention and other international agreements for migratory species for their special habitat value for waterbirds. These are ‘Windella’, ‘Crinolyn’ and ‘Goddard’s Lease’ on the Gingham Watercourse and ‘Old Dromana’ on the Lower Gwydir Watercourse. Their primary ecological features are large expanses of vegetation, including large areas of coolibah woodland, water couch and the largest stand of marsh club-rush in New South Wales (NSW).
When flooded, the wetlands can sustain up to hundreds of thousands of breeding colonial waterbirds. Environmental demands help support the ecological character of the Ramsar areas.
Environmental water is delivered to key locations to support the region’s unique native animals, plants, birds and fish that rely on health waterways including these nationally and internationally important wetlands.
Delivery of environmental water to date (as of September 2022)
A combination of Commonwealth and New South Wales water for the environment has been delivered to the Gwydir Valley since 2010-11. This water helps support wetland habitat, vegetation, native fish, frogs and waterbirds, and increases connection to the Barwon River.
The Gwydir Valley experienced very dry conditions between 2017–18 and 2019–20, with 2019 being the driest year recorded in decades. By summer 2018–19, most sections of the lower Gwydir River and Gingham Watercourse, as well as Carole Creek and the Mehi River, had dried back to a series of isolated pools. Water for the environment was delivered to key refuge pools during that time, to help support native fish to survive the drought.
Above average rainfall occurred between January and April 2020, providing several flows through the full length of the river system and some localised wetland inundation in the lower Gwydir, Gingham and Mallowa systems. Dry conditions then returned, with cease to flow conditions in some lower parts of the system by September 2020, which were broken by some unregulated events in October.
After the long dry, flows in 2020 and early 2021 started the process of recovery in the Gwydir. Water for the environment was delivered over summer 2020–21 to the lower Gwydir, Gingham and Mallowa Creek systems, and the Barwon River via Carole/Gil Gil creeks. Delivery of this water was designed to support the recovery of rivers and wetlands across the Gwydir system. Commonwealth water delivered in January via Gil Gil Creek to the Barwon River formed part of the Northern Waterhole Top-up flow, to improve water quality and support native fish.
Further rainfall, flows and wetland flooding occurred throughout 2021 and 2022. Vegetation has been responding well to flows. Delivering water for the environment during the dry times helped native plants and animals to hang on. This also helped them to bounce back stronger when wetter conditions returned.
Water for the environment was delivered to the Mallowa Creek and Wetlands in 2021-22 to help vegetation recover and build resilience. This water also had the additional benefit of providing foraging food for waterbirds that bred in huge numbers across the Gwydir Wetlands. Water for the environment also helped maintain low flow rates in the Gwydir Wetlands to assist waterbirds to complete their breeding cycles, and was used to help maintain connectivity to the Barwon River.
What has environmental water achieved in the Gwydir?
Scientific monitoring shows that water delivered to the Gwydir is providing food, habitat and breeding opportunities for many of the region’s unique native fish waterbirds, plants and wildlife, as well as maintaining and enhancing wetland vegetation condition.
A summary of results for 2021-22 are below with full monitoring reports available for previous years.
Water for the environment was delivered to the Mallowa Creek and Wetlands throughout summer and autumn to help vegetation recover and build resilience following the recent drought.
Water for the environment was also delivered to assist waterbirds that bred in large numbers across the Gwydir Wetlands. This water maintained low flows, ensuring water levels were kept stable under nests. This helped support the waterbirds to fledge in locations that otherwise would have drained, leaving the nests high and dry and susceptible to predation and abandonment. Flows also helped maintain feeding habitat.
Commonwealth environmental water use is planned, delivered and managed in partnership with a large range of individuals and organisations throughout the Gwydir Valley including:
- NSW Department of Planning and Environment - Environment and Heritage Group
- NSW Department of Planning and Environment - Water
- New South Wales Department of Primary Industries – Fisheries
- Gwydir Environmental Water Advisory Group
- Murray-Darling Basin Authority
The following videos were produced by the NSW Government Office of Environment & Heritage