Fishway program

Types of fishways

There are a range of types of fish passages being considered as part of the program including:

• Rock ramps - rock ramps are nature-like fishways providing passage and aquatic habitat through a simulated natural stream environment that contains pools, runs, riffles and rapids.
• Vertical slot fishways - vertical slot fishways are concrete channels extending from the top of the weir to the base. There is vertical slot to move water to the downstream pool. This creates a series of pools and small steps to enable fish to swim through.
• Fish locks - Fish locks are used to move fish over barriers between about five to 15 metres high. They include gates at the entrance, a holding chamber and gates at the exit. Fish locks attract fish into the holding chamber and when the exit gate opens the fish move from the chamber upstream.  of the barrier.

General information on fishways in NSW.

Assessing fish passage options

Barriers to fish passage must be considered when identifying the fishway type. Barriers can prevent the migration of native fish species and can have serious impacts for fish populations.

We consider a range of other factors when identifying the best fish passage for the specific location. These include:

• Height of structure.
• Land ownership
• River flows
• Downstream customers
• Other users of the waterway
• Geotechnical constraints
• Marine biologists
• Heritage management
• Operations and maintenance requirements
• Engineering design
• Procurement.

Projects currently being progressed include:

Eden Creek Weir Removal

Originally built in the late 1960s for drought protection and as a pumping pool for stock and domestic use, the weir no longer serves its original purpose. A detailed review was conducted on the Eden Creek Weir, which determined the structure as a barrier for fish passage within the system and recommended the removal of the weir.

The Eden Creek Weir removal project is a partnership between WaterNSW and Department of Primary Industries and Regional Development (Forestry and Fisheries). This project is funded by the NSW Marine Estate Management Strategy which aims to  improve fish passage in coastal catchments. The removal of the Eden Creek Weir will build on the previous fish passage removal works of Cookes Weir in the Richmond River, ensuring an unrestricted fish passage (more than 43km) within the system, and re-establishing natural environmental processes.

WaterNSW has completed environmental and cultural heritage studies to consider the potential benefits and impacts of the removal of Eden Creek Weir.

January 2026 update

• Initial engagement with local landholders and stakeholders occurred in December 2025
• Based on feedback received, WaterNSW will engage a platypus expert to review the Platypus Management Plan and assess how changes in upstream water levels could affect the local platypus population.
• DPIRD Fisheries will undertake surveys of the creek’s fish population, including identifying where carp are present in the system, and potential impacts of carp on the upper reaches of the creek.
• The additional studies and community feedback will form part of the Review of Environmental Factors (REF).

July 2026 update

An expert review of the Platypus Management Plan found that while the weir pool currently provides platypus habitat, potential impacts from weir removal on platypus can be effectively managed through careful planning and staged implementation.

Fish surveys and environmental DNA (eDNA) testing detected no carp upstream of the weir at the time of sampling. However, as the results only provide a snapshot of time during sampling, they do not confirm the absence of carp in the upstream reaches.

DPIRD Fisheries is planning additional seasonal surveys in the upper reaches of Eden Creek to better understand fish biodiversity upstream of the weir and potential species impacts should the weir be removed.

New survey findings will inform the Review of Environmental Factors (REF) and support future decision-making by WaterNSW and DPIRD Fisheries on the project.

Timeline

While these investigations continue, construction planning has been paused.

Removing the weir aims to restore Eden Creek’s natural flow and enhance fish passage, improve creek health and water quality.

For more information, view the:

• Eden Creek Weir Removal community update July 2026 (PDF, 438.79 KB)
• Eden Creek Weir Removal Fact Sheet. (PDF, 146.76 KB)

Lake Cargelligo Inlet Regulator, Lachlan Valley

Design options development work is underway to install a fish passage at the Lake Cargelligo Inlet Regulator. Work will also include the replacement of the regulator. We are working closely with nearby property owners during this stage of works. The current works will help assess the feasibility of this project and produce a business case to approve the next stage of work.

Gunidgera Weir, Namoi Valley

Design options development work is underway to install a fish passage at Gunidgera Weir. We will work closely with nearby property owners during this stage of works. The current works will help assess the feasibility of this project and produce a business case to approve the next stage of work.

Marebone Break Regulator No.1, Macquarie Valley

Design options development work is underway to install a fish passage atMarebone Break Regulator No.1. We will work closely with nearby property owners during this stage of works. The current works will help assess the feasibility of this project and produce a business case to approve the next stage of work.

Other locations

More locations will be announced when finalised in consultation with local stakeholders and we will continue to work closely with local communities, nearby property owners and interested stakeholders as works progress.

Visit this section of the project webpage for regular updates on recently identified locations and the status of each fish passage.

For general enquiries on WaterNSW’s work, please email us or call the WaterNSW Helpdesk on 1300 662 077.