Selected Area: Warrego-Darling

The Warrego-Darling is a unique and diverse system that supports a rich diversity of plants and animals in a constantly changing environment.  Our work here is to collect data, monitor ecosystem interactions and evaluate our findings so we can provide accurate and reliable information to the Commonwealth Environmental Water Holder for the effective management of environmental water.

Warrego River, Qld. Photo credit: Warrego Research Team

We acknowledge and respect the Traditional Owners as the First Peoples of the lands and waters of the Murray Darling Basin. We recognise their unique ability to care for Country and their deep spiritual connection to it. We honour Elders past and present whose knowledge and wisdom has ensured the continuation of culture and traditional practices. We are committed to genuinely partner, and meaningfully engage, with Traditional Owners and Aboriginal communities to support the protection of Country, the maintenance of spiritual and cultural practices and their broader aspirations in the 21st century and beyond.

Artwork credit: Wiradjuri Artist Rebecca Salcole

About Warrego-Darling

The Warrego-Darling Selected Area covers approximately 92,000ha and is located around 80km south-west of Bourke in north western NSW. The area receives flows from both the Warrego and Darling River systems and is encompassed by the Toorale National Park and State Conservation Area. The Toorale Property was purchased by the Australian Government in 2008 with the objective of returning the property’s water entitlements back to the river. Figure 1 depicts the location of the Selected Area within the Murray-Darling Basin.

Figure 1: The location of the Warrego-Darling Selected Area within the Murray-Darling Basin, showing upstream catchments.

The Warrego River relies heavily on rainfall in the north of the catchment for flows, whilst the Darling receives flows from both rainfall and releases of water from several upstream headwater storages. The Darling catchment drains approximately two-thirds of the Murray-Darling Basin and is a major tributary from the north, to the Murray River in the south of the basin. Around two-thirds (62,000ha) is classified as floodplain, with the remaining third (30,000ha) dryland.

The Warrego is a very flat system, with a number of small, shallow channels meandering their way through the floodplain before the main channel continues south, eventually joining the Darling River. The main channel is bordered to the west by the extensive Western Floodplain and has been highly modified due to the construction of seven dams which control flow down the channel and act as refuge pools in drier times. Boera Dam is the largest of these dams, and is located the furthest upstream as shown in Figure 2. Boera Dam enables water to either continue down the channel, or to be diverted onto the Western Floodplain, depending on water requirements downstream.

Figure 2: The Warrego-Darling Selected Area, NSW.

The Western Floodplain and dams along the main channel support an array of wildlife including waterbirds such as the Pied cormorant (Phalacrocorax varius), Darter (Anhinga melanogaster), Australian pelican (Pelecanus conspicillatus), Great egret (Ardea alba), Royal spoonbill (Platalea regia) and Brolga (Grus rubicundus) which is listed as Vulnerable in the NSW Threatened Species Conservation Act 1995.

The Warrego also supports a range of native vegetation species such as Coolabah, River Cooba, Black box, Lignum, saltbush and a number of forbs and grasses. These plant species provide important habitat and feeding grounds for waterbirds and raptors, as well as other terrestrial species like Eastern Grey (Macropus giganteus) and Red (Macropus rufus) Kangaroos, Emus (Dromaius novaehollandiae) and reptiles.

Native fish in Warrego-Darling

Native fish rely heavily on the Warrego-Darling system for refuge during dry times, feeding, spawning and moving throughout the system. Of the forty-six native fish species found in the Murray-Darling Basin, twenty-one have been identified in the Warrego-Darling Area. Five of these species are listed as vulnerable, endangered or critically endangered (see photos below).

Southern purple-spotted gudgeon (scientific name: Mogurnda adspersa). Photo credit: Fishes of Australia
Murray cod (Maccullochella peelii). Photo credit: DPI (Fisheries)
Freshwater catfish (scientific name: Tandanus tandanus). Photo credit: Fishes of Australia
Olive perchlet (scientific name: Ambassis agassizii). Photo credit: Fishes of Australia
Silver perch (scientific name: Bidyanus bidyanus). Photo credit: Fishes of Australia

The Warrego River system is highly variable, experiencing prolonged dry periods which are then interrupted by sporadic flood events. The Flow-Monitoring, Evaluation and Research Program (Flow-MER) will enable us to further develop our knowledge of species (plants and animals) resilience in such a variable environment.

Where water can be delivered, such as down the Darling, this information will enable us to make more timely decisions when it comes to releasing flows to benefit native fish, waterbirds and vegetation communities, particularly in times of drought.

It is also important that we continue to better communicate our findings to all stakeholders, so they can understand why this work is necessary and that the maintenance of healthy river systems is critical to the survival of numerous plants and animals, as well as providing the rich cultural, social and economic values of the area.

Our approach

The Flow-MER program is designed to assess how water for the environment effects ecosystem interactions within the Warrego Darling Selected Area. This involves monitoring and evaluating the response of key indicators including waterbirds, fish, water quality and movement, invertebrates (food webs) and vegetation to the presence and absence of water in the system.

The Flow-MER Program is a three year continuation of the Long-Term Intervention Monitoring (LTIM) project which took place 2014-2019. It will allow our team to continue to work identifying and recording how environmental water effects ecosystems within the Warrego-Darling.  We will also be extending our communication and research components.

Lindsay Frost sampling bugs in the Western Floodplain. Photo credit: Iris Tsoi
Ben Martin collecting data at a site in the Western Floodplain. Photo credit: Mark Southwell

Current work

We have a set of core indicators that we monitor and report on within the Warrego-Darling selected area. Our primary task is to assess the outcomes of environmental watering in the environment which we do across six areas of activity:

Hydrological analysis

We analyse what flow is coming down the Darling and Warrego Rivers. There is a long and complex network of rivers upstream of our monitoring points, and tracking when and where the water comes from takes a bit of wrangling. On the Warrego Western Floodplain we map the extent to wetland inundation using satellite image analysis. Our focus is on environmental water, when it is delivered and how far it moves.

Western Floodplain. Photo credit: Warrego Research Team

Food webs

Our team sample the rivers and wetlands regularly to understand changes in water chemistry with different flow types. We also survey for micro-invertebrates and macro-invertebrates to understand how changes in water lead to a productive food web. When water for the environment comes, we want to know how the water quality changes and the food webs it can support.

Sampling out in the Warrego. Photo credit: Warrego Research Team


If you water it, they will come. Over 6 years of surveys we have found that waterbirds will quickly arrive when the inundation arrives. They have responded rapidly to environmental watering and we have seen feeding, breeding and recruiting outcomes.

Brolga using wetland resources. Photo credit: Warrego Research Team
Pelican in flight. Photo credit; Warrego Research Team


Along the Warrego River, at the water holes, and on the Western Floodplain, we survey the number and diversity of frogs. Mostly we listen for their calls but we keep our eyes open too.

Photo credit; Warrego Research Team
Photo credit: Warrego Research Team


We survey the main dams and storages along the Warrego within the park, timing our surveys with flow events. So far, we have found the very cool Hyrtl’s catfish in large numbers and lots and lots of baby yellow belly. When we get a good flow we are getting good responses from our native fish.

Adult catfish. Photo credit: NSW DPI-Fisheries

What we’ve learned

Wetland inundation

Water for the environment contributed to intermittent flow events down the Warrego River including the inundation of the Western Floodplain. The 2016-17 water year saw the greatest flows during the 5 years we were doing our work through the LTIM project. Flows helped to maintain refuge pools and improve the quality of water in the Warrego system.

Image caption: Warrego River in flood.  Photo credit: DPE Environment and Heritage Group.

Better habitat for native fish

Our research found that fish were very resilient, surviving and maintaining populations during highly variable flow conditions. The deeper pools and upstream catchment played an important role in preserving fish populations during dry times. Fish were able to rebuild populations in response to rainfall and resultant flow events. When flow events occurred, we found that these refuge pools triggered the breeding of native fish including Golden perch (commonly known as Yellow belly), a threatened species.

Image caption: Golden perch.  Photo credit: Finterest

Rejuvantion of vegetation and ecosystems

During times of inundation, the Western Floodplain supported the rejuvenation of vegetation communities and ecosystems resulting in the greatest diversity, richness and abundance of invertebrate, frog and waterbird species of all monitored sites within the Selected Area.

Image caption: Litoria caerulea (Green tree frog) at Ross Billabong, Toorale. Photo credit: Warrego Research Team

Flow maintained in the Darling River

The Darling River kept flowing for the majority of the time due to rainfall events and the contribution of Commonwealth environmental water. Water for the environment helped to improve water quality and provide habitat within the Darling River as well as encourage the transfer of nutrients downstream.

Image caption: Darling river. Photo credit: Iris Tsoi
Major Mitchell cockatoo (Lophochroa leadbeateri). Photo credit: Dan McKenzie
Litoria peronii (Person tree frog). Photo credit: Warrego Research Team

Our team

Dr Paul Frazier

I am one of the Project Directors for the MER Program. I also organise and implement the communication strategies for the MER Program in the Warrego-Darling Selected Area. My role involves liaising with all stakeholders and analysing, writing up and communicating our findings with CEWH through our annual reports.

Dr Mark Southwell

I am one of the Project Managers for the Warrego-Darling Selected Area. I organise and undertake field trips, liaise with stakeholders and carry out technical work associated with hydrology and vegetation indicators. My role also includes writing up the project findings in our annual reports.

Dr Sarah Mika

I am one of the Project and Research Managers for the Warrego-Darling Selected Area. I sample and analyse the water quality, microinvertebrate and macroinvertebrate indicators. I am also responsible for the overall reporting of project findings.

Dr Gavin Butler

Gavin is the fisheries leader, and oversees and directs the fish sampling, analysis and reporting for the project. He even gets his feet wet sampling from time to time.

Dr Deborah Bower

I work for the University of New England and I am responsible for research and monitoring of biodiversity, including frogs and turtles. This involves organising and undertaking field work, liaising with landholders, and recording our findings so they can be written up in our annual reports for the Program.

Ben Vincent

I’m the vegetation ecologist for the Aquatic Ecology and Restoration Research Group at the University of New England. My role is to continue build on work already undertaken and collect data on the different wetland and floodplain plant species that come and go as a result of water availability.

Dr Ivor Growns

I am responsible for sample processing, data collation and reporting our findings for invertebrates. I coordinate the upload of all indicator data to the Monitoring Data Management System for the CEWH. I am also passionate about communicating our findings to the broader scientific community.

Dr Steve Debus

My role is to conduct the biannual waterbird surveys in the Warrego Selected Area. This involves going out in the field and identifying birds by sight and sound.

Shjarn Winkle

I work in stakeholder engagement and reporting. I help to compile and share our stories, write our reports and spend time in the field undertaking surveys.

Dr Leo Cameron

I am a Fisheries Project Manager/Fisheries Scientist. I frequently assist with the field work, data analysis and reporting. I also enjoy being a voice in the project design.

John St Vincent Welch

I schedule and run the Fisheries field surveys and handle data entry and data Quality Assurance and Control. I get in the boat and in the waders sampling fish in the most unlikely places.

Chris Bowen

I  undertake fisheries field survey, data entry and data Quality Assurance and Control, including ensuring sampling equipment is in good order.

Sam Lewis

I am an aquatic ecologist working with the Aquatic Ecology and Restoration Research Group at the University of New England. My role with Flow-MER involves conducting field surveys for a variety of aquatic indicators and providing support through laboratory and statistical analysis.

Ellen Ryan

I am involved with stakeholder engagement. I contribute to compiling and sharing of our stories as well as assisting with field surveys.

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