CTGM replacement - Brookfield Tunnel to Burmi Creek
We're planning to replace a 12-kilometre section of the Chichester Trunk Gravity Main (CTGM) between Brookfield Tunnel and Burmi Creek. The concept design plans and Review of Environmental Factors (REF) documents for this project are now on public exhibition and open to feedback.
Project overview
We're planning to replace a 12-kilometre section of the Chichester Trunk Gravity Main (CTGM) between Brookfield Tunnel and Burmi Creek.
The CTGM is a critical part of our water network, supplying around 40 per cent of the Lower Hunter's drinking water. This section of the pipeline was originally built in 1923 and is showing signs of deterioration.
Replacing the pipeline will help us continue to deliver a safe, reliable and resilient water supply for our region by:
- reducing leaks and conserving drinking water
- improving safety for workers and the community
- reducing the risk of unplanned water supply interruptions
- strengthening the network for future generations.
What we're planning
As part of planning for the replacement pipeline, we investigated different route options and assessed potential environmental, community and construction impacts.
Two main alignments were considered:
- a route alongside the existing pipeline through Columbey National Park
- an alternative route that diverts south-west after Woerdens Road and follows an existing powerline easement for much of its length.
Following detailed investigations, the alternative alignment was selected as the preferred route (pictured below). This option reduces impacts on native vegetation, threatened species habitat and environmentally sensitive areas compared with a route through Columbey National Park.
Where the route diverts around Columbey National Park, south-west of Woerdens Road, the new pipeline will be installed underground, primarily within an existing powerline easement. This approach was informed by landowner feedback and helps minimise impacts on surrounding properties and the environment. At the northern and southern ends, the route crosses several private properties before reconnecting with the existing alignment.
The replacement pipeline will also be slightly larger than the existing pipeline, increasing from 900mm to 1050mm in diameter. This will improve network capacity and help support water security into the future.
The existing CTGM will be removed once the replacement CTGM is built and connected in to the network.
Have your say
We've completed extensive investigations and environmental assessments to inform the project's concept design plans and Review of Environmental Factors (REF).
The concept design plans and REF are on public exhibition from 9am Monday 7 September to 5pm Sunday 4 October 2026.
We value local knowledge and encourage community members to review the documents and share their feedback. Your input will help us better understand local considerations and inform future planning and decision-making.
During the public exhibition you can:
- view the concept design plans and REF in the resource library below
- inspect hard copies at Dungog Shire Council - 198 Dowling Street, Dungog
- read our REF Overview brochure, which provides a summary of key information and links to relevant sections of the REF.
Public exhibition resource library
Some documents may not comply with accessibility requirements (WCAG) or may have a large file size (up to 50MB). If you are having trouble accessing information in these documents, display copies are also available to view at Dungog Shire Council or at Hunter Water's head office in Honeysuckle. Please contact CTGM@hunterwater.com.au for assistance.
Got questions?
We're available to answer your questions and discuss the CTGM replacement project. The project team will in Glen Oak for appointments on:
- Friday 18 September 2026
- Thursday 24 September 2026
Bookings are essential. To arrange a meeting, please call our project support officer on 0458 052 448 or email CTGM@hunterwater.com.au.
Make a submission
You can provide feedback by:
- completing the online feedback form below
- emailing your submission to CTGM@hunterwater.com.au
Submissions close at 5pm on Sunday 4 October 2026.
Hunter Water collects your personal information for the purpose of receiving and responding to submissions on the CTGM replacement public exhibition, and to provide updates about the project where you choose to receive them. Your information will be managed in accordance with our Privacy Statement.
What happens next?
After the exhibition period closes:
- Community feedback will be reviewed and key themes summarised in an outcomes report.
- The REF will be finalised, taking community feedback into consideration.
- A determination will be made on the proposed project.
- The community will be informed of the outcome.
Subject to approvals, detailed design and construction planning will continue.
Frequently asked questions
What is the CTGM?
The Chichester Trunk Gravity Main (CTGM) is a major water pipeline that supplies around 40 per cent of the Lower Hunter's drinking water. It transports water from Chichester Dam to water treatment and distribution facilities across the region.
Why does the CTGM need to be replaced?
The remaining 12-kilometre section of the pipeline between Brookfield Tunnel and Burmi Creek was built in 1923 and is deteriorating. Replacing it will help maintain a safe, reliable and resilient water supply while reducing the risk of leaks, failures and unplanned interruptions.
What are the benefits of replacing this section of CTGM?
Replacing the CTGM between Brookfield Tunnel and Burmi Creek will:
- reduce leaks and conserve drinking water
- maintain a reliable water supply for the region
- improve safety for workers and the community
- replace ageing infrastructure with a more resilient pipeline
- help strengthen water security for the future.
What is a Review of Environmental Factors (REF)?
A Review of Environmental Factors (REF) is an environmental assessment that identifies and evaluates potential impacts of a proposed project before work begins.
The assessment considers matters such as biodiversity, heritage, traffic, noise, water quality and property impacts, and outlines measures to avoid, minimise or manage potential impacts.
Why are you seeking feedback?
Community members and landowners have valuable local knowledge that can help inform project planning. Feedback received during the public exhibition period will be considered as we finalise the REF and continue project planning.
How was the preferred route selected?
The route was selected following environmental, engineering and operational investigations. It was chosen because it reduces impacts on native vegetation, threatened species habitat and environmentally sensitive areas while also considering construction requirements.
When will construction start?
Subject to approvals, construction is expected to commence from 2029 and will be completed over several years.
Will my water supply be affected?
The replacement pipeline is being carefully planned to maintain a reliable water supply throughout construction. Once completed, the new pipeline will help reduce the risk of future supply interruptions.
Will construction create noise or traffic disruptions?
Some temporary impacts are expected during construction, including increased vehicle movements, noise and vibration near work areas. Management plans will be developed to minimise impacts and maintain safety for residents, businesses and road users.
Will private land be affected?
Some land acquisition and new easements will be required along sections of the route. We will continue working closely with affected landowners throughout the planning and delivery of the project and will seek to minimise disruption wherever possible.
How will environmental impacts be managed?
The project has been designed to reduce environmental impacts wherever possible. This includes avoiding significant clearing in and near Columbey National Park, using existing cleared corridors where practical, protecting waterways through specialised construction methods and rehabilitating disturbed areas after construction.
How can I make a submission?
You can provide feedback by completing the online feedback form on this webpage, emailing CTGM@hunterwater.com.au, or writing to:
Hunter Water
Attention: CTGM Project Team
PO Box 5171
HRMC NSW 2310
Can I speak directly with the project team?
Yes. The project team will be in Glen Oak for meetings by appointment only on Friday 18 September and Thursday 24 September 2026. You can book a meeting with the project team by calling 0458 052 448 or emailing CTGM@hunterwater.com.au. Bookings are essential.
What happens after the public exhibition closes?
We'll review all feedback received during the exhibition period, finalise the REF, determine the project's next steps and keep the community informed throughout the process.
Other project materials
View previous project updates and information