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Waterbirds depend on rivers and wetlands to provide foraging, breeding, roosting and nesting habitat, as well as protection from predators. They are highly mobile and can move from catchment to catchment in search of suitable conditions.

The Murray–Darling Basin contains nearly half of all wetlands where colonial nesting waterbirds (birds that nest in large colonies) breed in Australia. The spectacular colonies and high concentrations of waterbirds on many of the Basin’s wetlands were the catalyst for their nomination as wetlands of international importance under the Ramsar Convention.

Many colonial nesting waterbirds require wetlands to be flooded to start and complete breeding. As a result of river regulation, floods have become smaller and less frequent, with wetlands experiencing longer dry spells as much of the water is used for other purposes and captured in dams. Long-term surveys have shown a decline of more than 70% in the total population of waterbirds since 1983.

Shorebird numbers fluctuate from year to year. These species rely on multiple international 'staging' sites during their annual migration and are highly specialised foragers, requiring exposed tidal flats for feeding opportunities. Observed long-term declines in these species' abundance could also be a result of river regulation or degradation at other international 'staging' sites, which may affect counts in the Coorong, regardless of conditions there.


Basin environmental watering priorities for waterbirds

The Basin-wide environmental watering strategy outlines what is needed to restore waterbird populations to levels similar to those in the early 1990s. These levels are necessary to ensure populations are large enough to survive dry conditions and other changes to the Basin’s river systems. The strategy also outlines what is needed for migratory shorebirds in the Coorong and Lower Lakes.

Annual environmental watering priorities for 2018-19

  • Provide flows to improve habitat and support waterbird breeding
  • Maximise availability of productive foraging habitat for shorebirds

The annual environmental watering priorities are the focus for the current year and are small steps in the short term to achieve the multi-year watering priorities in the long term.

Multi-year environmental watering priorities

The annual environmental watering priorities support multi-year environmental watering priorities that remain in focus over a number of years to achieve long term outcomes. Multi-year watering provides and relies on cumulative progress over time, e.g. watering in one year may only wet a dry riverbed, but follow up watering the next year provides more water to fill the river and reach wetlands either side of the river where it waters plants and animals.

More information


The multi-year priorities are listed below:
Improve the abundance and maintain the diversity of the Basin’s waterbird population

Restoring waterbird populations relies on successful breeding, a diversity of habitats in good condition and protection of drought refuges. The availability of breeding habitat and food resources is closely linked with wetland inundation, which will increase as more water is made available for the environment under the Basin Plan.

Waterbird abundance 

Maintain the abundance of key shorebird species in the Coorong and Lower Lakes

Maintaining the shorebird populations in the Coorong and Lower Lakes requires maximising the availability of productive foraging habitat during summer when migratory species are building body condition in preparation for their northward migration.

Counts of Curlew Sandpiper, Common greenshank, Red-necked Stint and Sharp-tailed sandpiper and average Coorong water levels in January from 2000-2017 (Paton, 2017). The 2019 red bars represent species' targets to be reached by 30 June 2019, as outlined in the Basin-wide environmental watering strategy.

How does the MDBA decide where water needs to be delivered?

Where and how much water for the environment is delivered depends on a number of different factors including climate (e.g. rainfall and soil moisture). These factors are measured by the Resource Availability Scenario. For more information visit the Resource Availability Scenario page.