Monitoring - Northern Unregulated Rivers (Intersecting Streams and Barwon-Darling)

• Overview
• Latest water use
• Portfolio & Planning
• Monitoring
• History

Monitoring, evaluation and research

Brolga at Toorale.
Photo: Lachlan Copeland

Monitoring and evaluating the use of water for the environment is helping to build knowledge about the best way to improve the health of the rivers and wetlands of the Basin.

The Commonwealth Environmental Water Office (CEWO) works with Basin states, the Murray-Darling Basin Authority, scientists and the local community to build this knowledge.

There are a number of programs currently underway in the Northern Intersecting Streams.

Some recent examples of learnings include:

Warrego

• Commonwealth water for the environment contributes to the breeding and recruitment of native fish species (e.g. golden perch) in the Warrego system. Golden perch recruits from the Warrego are likely to be contributing to the wider population in the Darling River system.
• The fish community in the Warrego River are highly resilient and can survive highly variable flow conditions, including drying down. They are then able to recolonise and recruit on the larger flows.
• Supporting the main waterholes on the Warrego is important for providing source populations of native fish and providing refugia for waterbirds.
• Using water for the environment to inundate parts of the Western Floodplain increases productivity that support the highest abundance and diversity of frogs, invertebrates and waterbirds. It also increases the cover and richness of vegetation.

Juvenile golden perch sampled in Booka Western bywash, May 2019. Photo: Eco Logical Australia

Condamine-Balonne

• Lagoons in the Queensland Lower Balonne are known to provide important habitat for a range of native fish species including golden perch, Australian smelt, spangled perch, bony bream, olive perchlet and Hyrtl’s tandan.
• Monitoring has shown that prolonged drought has reduced the condition of all vegetation community types at the Narran Lakes (Dharriwaa), with river red gum being the most affected tree species.
• Despite significant dieback at the Narran Lakes, lignum has been shown to resprout in response to rainfall and may still provide suitable nesting habitat for waterbirds following inundation. The final report for this monitoring project is at: Vegetation Community and Tree Stand Condition Assessment of the Flood-Dependent Vegetation of Narran Lakes Nature Reserve (Dharriwaa) (2020-2021) .
• A pilot project in 2020 demonstrated that additional water can be provided to the Narran Lakes via reimbursement to water-licence holders that refrain from pumping water they are legally entitled to take. This project meant that more water from the Lower Balonne remained in the river and reached the Narran Lakes, helping to revive some critical waterbird habitat.
• After wetter conditions from early 2020 onwards, waterbirds bred at the Narran Lakes from January to April 2022. This is the first time that colonial waterbirds have bred at at that site in a decade, and the first time in more than 20 years that there has been waterbird breeding at Macquarie Marshes, Gwydir Wetlands and the Narran Lakes at the same time. Around 10,000 straw-necked ibis nests were detected in two colonies, with other species including royal and yellow-billed spoonbills and egrets also recorded as nesting. For more information on 2021-22 Narran Lakes waterbird breeding, please see: Final Report June 2022 - Dharriwaa-Narran Lakes Nature Reserve Colonial Waterbird Reproductive Success Monitoring 2022.
• The Commonwealth Environmental Water Office also invested in waterbird satellite tagging to track how birds move in the landscape at the Narran Lakes and other sites in the Murray-Darling Basin. More information on waterbird tracking can be found at: Satellite tracking.

Barwon-Darling

• Connectivity between the Barwon-Darling and its tributaries can be enhanced using water for the environment, which is important for supporting native fish movement.
• Commonwealth water for the environment delivered as part of natural flow events can improve water quality, nutrient cycling and provide access to habitat for aquatic species.
• Extended dry periods and cease to flow conditions results in significant loss of freshwater mussels in the Barwon-Darling and its tributaries. The provision and protection of minimum baseflows is vital to their recovery and persistence.
• Delivering water for the environment through channels that are already wet minimises water quality issues. The water needed to replenish waterholes and allow for seepage is also much greater in rivers that have ceased to flow compared to still flowing rivers.
• The protection of water for the environment in the Barwon-Darling is very important for achieving the environmental outcomes targeted.

CEWO MER Program

The CEWO Monitoring, Evaluation and Research (MER) (Flow-MER) Program integrates and replaces monitoring and research activities under the Long-Term Intervention Monitoring (LTIM) and Environmental Water Knowledge and Research (EWKR) projects.

A detailed MER Plan has been developed for the Warrego-Darling MER Selected Area which sets out the schedule of activities to be undertaken in the Warrego-Darling to June 2022. The MER Warrego-Darling Selected Area project has been extended for a further twelve months.

CEWO Short Term Intervention Monitoring

The CEWO has funded monitoring activities to evaluate the short-term (annual) environmental response of selected watering actions in the northern unregulated rivers. Final reports can be found in the table below.

Monitoring, Evaluation and Research Activities and Reports