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:

Current status - Eden Creek Weir Removal

August 2026

Originally built in the late 1960s for drought protection and as a pumping pool for stock and domestic use, Eden Creek Weir no longer serves its original purpose. The weir was identified as a potential barrier to fish movement and NSW Department of Primary Industries and Regional Development (DPIRD) Fisheries requested WaterNSW’s support to investigate its potential removal.

Project planning activities for the Eden Creek Weir removal project have stopped and no construction activities will be undertaken. DPIRD Fisheries is planning further fish surveys in the upper reaches of Eden Creek to better understand fish biodiversity upstream of the weir and the potential impacts and outcomes should the weir be removed. These surveys are proposed to be undertaken across multiple seasons to provide a more comprehensive understanding of fish populations and habitat use.

The findings from these investigations, together with community feedback and other environmental studies, will inform the Review of Environmental Factors (REF) and support future decision making.

WaterNSW and DPIRD Fisheries thank local landholders and the community for their involvement and feedback to date.

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.