Lower Balonne Flow-MER
The Centre for Ecosystem Science undertakes monitoring, evaluation and research (MER) on behalf of the Commonwealth Environmental Water Holder (CEWH) in the Lower Balonne River system including the internationally significant, Ramsar-protected Narran Lakes (Dharriwaa).
About the Lower Balonne Area
The Lower Balonne Area encompasses the Lower Balonne Floodplain, supports the largest number of wetlands of any catchment in the Murray–Darling Basin (MDB), and makes up two-thirds of the Condamine–Balonne Valley, one of the largest catchments in the MDB.
New to the Commonwealth Environmental Water Holder’s (CEWH) Flow-MER program in 2024, the Lower Balonne covers two million hectares across Queensland and NSW and is home to the Culgoa, Balonne, Condamine and Narran rivers and adjacent floodplains and wetlands. It includes the internationally significant and Ramsar-listed Narran Lakes (Dharriwaa).
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The lands of the Lower Balonne have been important to Aboriginal People for thousands of years with their history, culture and livelihoods closely intertwined with its river systems.
The Lower Balonne provides habitat for a diverse range of plants, including endangered vegetation communities, and habitat for waterbirds, native fish and many vulnerable and endangered species.
At Narran Lakes these include nationally and internationally threatened wetland-dependent species such as the Australasian bittern, Murray cod and Winged peppercress.
Narran Lakes supports at least 65 waterbird species, including 14 listed under international migratory agreements. The lakes are a waterbird breeding site for Ibis, Egrets, Royal spoonbills and Pelicans.
Permanent waterholes in the Lower Balonne’s main and distributary channels provide critical fish habitat during low or cease-to-flow periods. Many species persist in these areas until larger flows allow them to recolonise the system.
The Commonwealth Environmental Water Holder (CEWH) manages a suite of unregulated and overland flow licences in the Lower Balonne. These licences provide access to river and overland flows when certain conditions are met. The CEWH can also implement Event-Based Mechanisms under certain conditions to protect additional water in the Lower Balonne.Â
Research themes
Our monitoring, evaluation and research (MER) in the Lower Balonne informs the following themes:
Native vegetation
Our native vegetation studies in the Lower Balonne aim to understand how environmental water contributes to maintaining, improving or influencing woodlands, lignum shrublands and non-woody wetland vegetation, and the resilience of vegetation to fire.
Study methods include field surveys and remote sensing. Belt transects will be used to investigate vegetation responses along shorter gradients including riparian transects for key channels and water bodies.
Key 2024–2025 activities include selecting field sites and mapping vegetation across the study area.
Native fish
Our native fish studies aim to understand how water for the environment contributes to population structure, abundance, diversity, recruitment and condition.
Sampling will be conducted annually at sites with water in late summer/autumn.
The 20 sampling sites are located from below Beardmore Dam in Queensland through into NSW above the confluence with the Barwon River. It includes sites on the Narran, Culgoa, Bokhara and Birrie rivers.
Boat and backpack electrofishing, un-baited traps and fyke nets are used to undertake the work.
Initial fish sampling was undertaken in October 2024 to understand which fish species use Narran Lakes. View a summary of the results or the full report.Â
Waterbirds
Our waterbird studies aim to understand how water for the environment contributes to the abundance and species diversity, breeding occurrence, habitat provision and support, and breeding success for large breeding events.
The team undertake four repeat sets of ground-based field surveys at 10 sites annually plus annual spring aerial and ground surveys. We also utilise acoustic recorders and continuously monitor water depth and inundation.
The focus for the 2024-2025 year, the project’s first year, is field surveys, and the deployment of depth loggers and acoustic recorders.
River flows and connectivity
Our river flow and connectivity studies aim to understand how the river and wetlands work together under a range of flow scenarios with different water inputs including flow regimes, hydrological connectivity, and biotic indicators (e.g. waterbirds and flood-dependent vegetation).
The team utilise a range of data sources, satellite imagery, river gauges and depth loggers.
Our 2024–2025 activities are focused on the establishment of a data archive, computing environment, and workflow for satellite imagery, inundation models, gauge and logger data.
Cultural outcomes
The Dharriwaa Elders Group and Narran Lakes Nature Reserve Joint Management Committee are the cultural advisors for the Lower Balonne Flow-MER region. They support relationship-building between Aboriginal People with connection to Country and UNSW staff which is our focus for 2024–2025. Cultural advisors work with Aboriginal People with connection to Country to:
- Facilitate knowledge sharing between Aboriginal People, and between Aboriginal People and UNSW staff
- Identify opportunities and activities to support the values and aspirations of Aboriginal People
- Facilitate opportunities for Aboriginal People to be involved in the design and implementation of Flow-MER projects and activities.
In working together, UNSW supports the protection of Indigenous Cultural and Intellectual Property (ICIP) and Indigenous Data Sovereignty rights as appropriate for the Aboriginal People we work with.