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Wilcannia Weir Replacement Project

The new weir will provide long-term town water security for Wilcannia.

New site for Wilcannia Weir

About the project

The largest investment in water infrastructure along the Darling-Baaka River in decades, the $76 million Wilcannia Weir Replacement Project seeks to improve water security for the township of Wilcannia, enhance cultural connection to the river for local communities and deliver improved native fish migration along the river system. It will achieve this by constructing a new weir and fishway downstream of the existing failed weir.

The new weir will boost water storage by 20 percent, providing long-term town water supplies to preserve and enhance the social, economic and environmental benefits for Wilcannia, its people and its surrounds.

The project is jointly funded by the NSW and Australian Governments.

Project need

The existing Wilcannia Weir was built in 1942 for the purpose of providing a more reliable town water supply for Wilcannia. The existing weir has now failed and there is a need to support long-term town water security for the community by providing suitable water infrastructure, including a new weir.

Integrated approach to improving water security and quality

The NSW Government is taking a new integrated, system-wide approach to improving water security and quality for the Wilcannia community.

This approach will include both new water infrastructure as well as works to improve the supply of potable/drinking water and management of water and wastewater infrastructure.

The Water Group in the Department of Climate Change, Energy, the Environment and Water will lead this approach by:

  • constructing a new weir and fishway to replace the failed existing weir
  • supporting Central Darling Shire Council to build a new water treatment plant for the town
  • investigating a potential new groundwater bore with a reticulation network to supplement the town’s existing water infrastructure
  • improving the town’s existing water network to reduce leakage and losses
  • protecting the town’s stormwater systems to reduce public health risks.

This will ensure better water security and quality outcomes are delivered for the community.

Project status

The Australian and NSW Governments remain committed to constructing a new weir and fishway ~5 km downstream of the existing failed weir in Wilcannia.

While both governments remain committed to delivering this key piece of infrastructure, the design of the new weir and fishway has changed.

The new weir will be a fixed crest type and the crest height will be approximately 4.2m with the highest points on the outer edges being approximately 5.5 metres.

It will provide an additional 400 ML of water security for the town. This will boost water storage by 20 percent and is a significant step change in water security for Wilcannia. The new weir design has been developed to allow for future modification if required, including being raised, subject to additional funding being sourced and planning approvals being granted.

Unlike the old weir, the new design includes a fishway allowing fish to migrate upstream past the weir. It will be a vertical-slot type fishway and will be constructed next to the northern bank of the river.

The new design improves water security for Wilcannia while also being safer and more affordable, with less impact on the environment and culturally significant sites.

The decision to move to a new design was shaped by the responses to the Environmental Impact Statement public exhibition in 2022, and extensive stakeholder consultation and feedback since scoping studies for the new weir began in 2016. The Environmental Impact Statement documents are available on the NSW Planning Portal website.

The NSW Government has an ongoing commitment to local employment into the construction phase of the project and to date has invested $4.63 million in the community through training programs, local procurement and cross-agency support.

Wilcannia weir aerial map.
Weir and fishway detailed concept design (aerial view).

Image

A high resolution version of the weir and fishway detailed concept design (aerial view) is available.

Download the images (PDF. 1,023KB)
NSW environmental planning approval process for projects over $30m
A diagram showing where we are in the environmental planning approval process as of April 2024

Diagram

A diagram outlining the environmental planning approval process for the project is available.

Download the diagram (PDF. 268KB)
Project benefits

The project, combined with the new approach, will deliver a range of benefits including:

  • improved water security and quality for Wilcannia
  • additional sources of potable water in times of drought
  • enhanced cultural connection to the river
  • improved water management of the weir pool
  • increased tourism and investment opportunities
  • better recreational amenity to walk, swim, picnic and fish
  • improved native fish migration.

While the design of the weir has changed, other key components of the project remain the same and are complete or well underway.

These include:

  • conducting geosurvey activities to inform the final design of the weir
  • upgrading Wilcannia’s sewerage system to prevent sewage from getting into the stormwater drains and ending up in the Darling-Baaka River
  • developing a Community River Place for recreational use in collaboration with community representatives

View more information about these activities below.

Geotechnical and geophysical studies

In June to August 2023, the Water Group completed a series of geotechnical and geophysical assessments at the new weir site. The soil samples and data collected have been assessed to help inform the detailed design of the project.

The assessments involved drilling boreholes on the northern and southern bank of the Darling-Baaka River to analyse ground conditions, as well as on-water assessments to determine the riverbed and sedimentary profile in-and-around the new weir location. These on-water assessments were conducted by boat using non-intrusive acoustic and seismic technology.

Further site investigations were also undertaken to support access during the project’s construction phase and to analyse materials that could potentially be used to help build the weir.

These studies used aerial drones and terrestrial scanning technology to investigate in greater detail the current weir site (for decommissioning), the new weir site (to inform the final design) and some elements of Union Bend Rd. They were completed in August 2023.

A local Wilcannia community member attended the works to provide cultural monitoring.

Sewerage upgrade (stormwater mitigation) works

The Water Group has completed stormwater (sewerage) mitigation works in Wilcannia, providing a low-maintenance, affordable and reliable solution to protect against effluent overflows.

The upgrades to the Hood and Martin Street sewage pump stations will prevent instances of raw sewage flowing into the stormwater system and then into the Darling-Baaka River system.

New pipework and two high-powered diesel pumps have been installed to provide a back-up in the event of a power failure or blockage. The pumps will automatically spring into action if the underground effluent reaches a high level, preventing untreated waste from spilling out.

The works provide vital protection for the local environment in the short-term and the new downstream weir pool in the long-term by ensuring sewage does not get into the stormwater drains and end up in the river.

Community River Place (Ngatji Hole)

The Water Group is currently working on the final design of the Community River Place.

The need for a Community River Place was raised during our discussions with the Wilcannia community. The site will provide an important recreational area for locals, a place where the community can gather to share stories, fish and swim.

The Water Group held a collaborative workshop with community representatives in December 2023 to discuss the concept design for the site.

The aim of the workshop was to get community feedback on the concept design, which will provide vital inputs for the final design.

The feedback provided is currently being incorporated into the final design, which we will take back to the community in the coming months.

Community consultation

The Water Group understands the importance of the river to the community and wants to design and construct a weir meeting community needs and expectations and maintaining the strong connection people have to the river.

Engagement on the project is ongoing and we will continue to provide opportunities for local communities and stakeholders, including Traditional Owners and First Nations communities, to have their say on the project as it progresses.

How the project is creating local employment opportunities

Learn about the Union Bend Road upgrade and how it is supporting employment in the Wilcannia region.
March 2022

The training initiatives as part of the project

The Water Group continues to work closely with key stakeholders to provide the local community with employment training opportunities. Hear from some of the Wilcannia locals who have completed training and development programs as part of the new weir project.
April 2021

Fact sheet

The department is designing and constructing a new weir and fishway for Wilcannia to replace the existing failed weir. A printable fact sheet about the project is available.

Download the fact sheet (PDF. 832KB)

Project updates

Related news

Contact us

For more information about the project, email us at wilcanniaweir@dpie.nsw.gov.au or call 1300 081 047.