Burtundy Fishway

Burtundy Weir and fishway

Burtundy Weir is located 133km upstream of the confluence of the Murray and Darling-Baaka rivers and is the first barrier experienced by fish moving upstream in the Darling-Baaka River. Burtundy Weir is a privately owned fixed crest weir, approximately 1.2m high. The weir’s primary function is to provide a weir pool to local landholders during low-flow periods.

The existing Burtundy Weir fishway was constructed in 2008. Assessments of the fishway completed in 2021 and 2022 under Commonwealth funding, both recommended that this structure be replaced with a new fishway that meets current performance criteria to significantly enhance fish passage at the site across a broad range of flow conditions.

As part of the same Phase 1 Commonwealth funding, concept and detailed designs including costings for a new vertical slot fishway at Burtundy were completed in 2023. The new Burtundy fishway has been designed to ensure that water velocity and turbulence remain within design parameters without any regular adjustments or maintenance. The fishway will be built on a maximum slope of 1 in 24. It will consist of 15 x 2 m wide and 3 m long cells (pools), with the entrance slot re-oriented to align with river flows and maximise fish attraction. The vertical slots have been designed to function over a flow range of 20–1000 ML/d. The weir becomes completely submerged at a flow of approximately 1500 ML/d.

Commonwealth funding is committed to the next phase of the project, with suitable flow conditions now required to move into the construction phase.

Previously Lower Darling Fish Passage Program

In February 2019, the Commonwealth and NSW Government agreed in-principle to the Commonwealth providing up to $1.1 million in funding for the Lower Darling Fish Passage Program to be managed by DPIRD Fisheries for Phase 1 delivery.  The entire funding envelope for the two-phase program was $6million. The Lower Darling Fish Passage Program was a coordinated and strategic plan to refurbish existing fishways at Burtundy, Pooncarie and Weir 32 to restore connectivity along the Lower Darling-Baaka (518 km). Importantly, the goal was for the Lower Darling Fish Passage Program to provide connected habitat between key rivers and floodplains to achieve meaningful and measurable improvements to native fish populations.

Phase 1 activities were to involve:

• Assessment of Burtundy, Pooncarie and Weir 32 fishways to identify issues impacting fish passage.
• Development of concept and detailed designs and cost estimates for refurbishment of the three (3) fishways.
• Development of a Business Case for submission to the Commonwealth Government for assessment for Phase 2 funding. DPIRD Fisheries were to manage the development and submission of the Business Case.

During the assessment of the three weirs, it was found that the existing Burtundy and Pooncarie fishways could not be modified to meet contemporary design standards and were recommended for complete replacement. It was also determined that the Weir 32 fishway could be modified for lower flows, however a new high flow fishway would be required for flows higher than 2,500 ML/d. Concept and detailed design, including costings, proceeded for a new Burtundy fishway.

The Weir 32 and Pooncarie fishway upgrades are now being investigated as part of the Menindee Fish Passage Business Case (2024-2027).