Menindee Permanent Fish Passage Business Case
The Baaka River supports a rich mix of native fish including Murray Cod, Golden Perch and Bony Herring. However, the regulators and weirs throughout the Menindee Lakes and in the main-stem Baaka River block native fish migration, concentrating fish biomass in the weir pool and contributing to conditions that can lead to repeated fish kills when water quality declines.
To address this challenge, the NSW Government committed $25 million to establish the Restoring the Darling-Baaka River Program. This program aims to nurse the system back to health using ground-breaking science, data and infrastructure.
The NSW Government response to Recommendation 4 from the Office of the Chief Scientist & Engineer (OCSE) Review committed to developing a full Business Case for permanent fish passage at the Menindee Lakes, as well as in the Lower Baaka including Weir 32 and Pooncarie Weir.
The business case, managed by DPIRD Fisheries and the Murray Darling Basin Authority (MDBA), in collaboration with partner agencies, will investigate holistic connectivity outcomes for the Menindee Lakes System and the Lower Baaka by exploring permanent fish passage solutions at up to 15 existing river regulators and lake-control structures, plus a number of road crossings.
3Rivers (a joint venture between Jacobs and GHD) are leading the development of this work - they have been appointed via a competitive procurement process. They are providing technical expertise to design and cost permanent solutions to restore fish passage. For more information on the Business Case, read the fact sheet.
The business case process includes:
- Initial investigation and options development
- Stakeholder consultation
- Concept design
- Environmental assessments
- Cost-benefit analysis.
In addition to the $6 million committed by the NSW Government, the Australian Government has provided $3.56 million in funding for business case development.
This business case work is in addition to the trial of the temporary fishway 'Fishheart' led by DPIRD Fisheries at the Lake Wetherell Outlet Regulator as a short-term solution to reduce the fish biomass in the Menindee town weir pool. Visit our project page for more information on the Temporary Tube Fishway Trial.
Read the Frequently Asked Questions (FAQs) for more information on the business case development.
For further information about the Menindee Permanent Fish Passage Business Case, please contact our team on fish.passage@dpird.nsw.gov.au.
FAQs
What is fish passage and why do we need it?
Australian native fish require unimpeded access along waterways to survive and reproduce. Different fish move within waters at different times to access food and shelter, to avoid predators, and to seek out mates. Some species such as Golden Perch can migrate thousands of kilometres while others only need to move a short distance.
Regardless of scale of movement, barriers to fish passage prevent the ability of native fish species to move and can have severe implications for these populations. In extreme cases, barriers can result in localised extinctions.
What is the significance of fish passage at the Menindee Lakes?
The Lower Baaka and Menindee Lakes are highly productive systems that support significant populations of native fish, especially following flow events that can create an ecosystem boom.
As new fish move into the Lower Baaka with inflows from the Northern Basin, the lakes provide ideal habitat and food for fish to grow, improve their condition and be ready for further movement opportunities on warmer waters
Currently in the Lower Baaka, fish can only migrate upstream as far as Lake Wetherell and Menindee Main Weir, with regulators and weirs blocking fish passage and contributing to significant increases in fish biomass, especially in the Menindee town weir pool.
What is the Menindee Permanent Fish Passage Business Case project?
In response to the Office of the Chief Scientist and Engineer's (OCSE) Independent Review into the 2023 Mass Fish Deaths in the Darling-Baaka River at Menindee, the NSW Government committed $25 million to establish the Restoring the Darling-Baaka River Program.
The NSW Government response to Recommendation 4 from the OCSE Review committed to developing a business case for permanent fish passage solutions on the Lower Baaka River and the Menindee Lakes System.
The NSW-led business case being undertaken by DPIRD Fisheries and partner agencies will investigate holistic connectivity outcomes for the Menindee Lakes System and Lower Baaka by exploring permanent fish passage solutions at up to 11 existing river and lake control structures plus a number of road crossings. This will be delivered by June 2027.
In addition to the $6 million committed by the NSW Government for business case development, the Australian Government has provided the Murray-Darling Basin Authority (MDBA) with $3.56 million for business case development for fish passage options at Lake Pamamaroo and Lake Wetherell outlet regulator to prioritise connecting the main stem Lower Darling-Baaka River.
The business case process will include initial investigation, stakeholder consultation, concept design, environmental assessment, cost-benefit analysis, detailed design and preparation of a full business case. The design work will be undertaken by a lead consultant who will be chosen by an open tender process.
How long will it take to complete the business case?
The development of the DPIRD Fisheries-led Menindee and Lower Darling-Baaka Permanent Fish Passage Business Case will be an iterative process over the next two years. The first year will include the development of a strategic business case that will consider all options for fish passage at priority sites and guide investment and decisions about preferred fish passage solutions to take forward. Detailed designs, including cost-benefit analysis, will then form part of the final full business case that will be delivered to the Government after year two.
The MDBA-led business case for permanent fish passage at Lake Pamamaroo and Lake Wetherell outlet regulator is targeting the completion by the end of 2026 to guide future investment decisions.
When is work starting on this project?
Actions have progressed and early planning work is underway, including the establishment of a steering committee led by the MDBA that brings together federal and state agencies, and is supported by technical advisory groups and project management teams.
The initial focus of early planning works has been for the appointment of a lead design consultant with the release of an open tender on 1 April 2025, with a series of site inspections to be undertaken as part of the tender process.
Community engagement will be a critical part of this process, and planning for this is underway. First Nations communities and local stakeholders will play a key role in shaping the options, design, cost-benefit analysis, and final recommendations, ensuring local and cultural knowledge is embedded in the outcomes.
Who can I talk to about this project?
For further information about the Menindee and Lower Darling-Baaka Permanent Fish Passage Business Case please contact the DPIRD Fish Passage team at fish.passage@dpi.nsw.gov.au.
How will the business case development impact the tube fishway trial?
Due to the complexity of the existing weirs and regulators that allow flow management throughout the Menindee Lakes system, the design of effective fish passage solutions through the system can present significant challenges.
Unfortunately, there is no one size fits all solution to restore fish passage in this system; however, this exciting tube fishway trial at the Lake Wetherell Outlet Regulator is about finding a cost-effective temporary solution while DPIRD Fisheries develops a Business Case with partner agencies to find effective and permanent fish passage solutions.