CTGM replacement Brookfield Tunnel to Burmi Creek

We're planning to replace the Chichester Trunk Gravity Main (CTGM) between Brookfield Tunnel and Burmi Creek. Condition assessments of the CTGM over the past few years have revealed the main, originally built in 1923, needs to be replaced.

Replacing the 12km section of the CTGM between Brookfield and Burmi Creek will:

• reduce leaks, which will help conserve precious drinking water
• improve safety for workers and the community
• help maintain a consistent supply of drinking water to the region.

Two possible alignments have been considered for the replacement main:

• The first runs next to the existing main, through the Columbey National Park.
• The second alignment would divert southwest after Woerdens Road and follow an existing powerline easement towards Clarence Town Road in the south.

Preferred route for the replacement CTGM

Over the past year, we’ve carried out a range of investigations on both alignments to help inform route selection including aerial surveys, environmental assessments, flood surveys, and geotechnical studies to better understand ground conditions.

Taking into account environmental and community impacts, constructability, cost, and relevant legislative requirements, the alternate alignment has been selected as the preferred route for the replacement CTGM.

One of the key reasons for selection of the alternate route is that it has less of an impact on threatened ecological communities than constructing the replacement CTGM through the Columbey National Park.

The preferred route for the replacement CTGM follows the existing CTGM corridor from Brookfield towards Woerdens Road, as indicated by the blue line on the map. This section will be an aboveground pipe.

The route diverts to the southwest just after Woerdens Road and then, for the most part, follows an existing powerline easement on the boundary to several private properties, as indicated by the orange line on the map. It will pass through several private properties at the northern and southern ends where the new route ties back into the existing route.

Based on feedback from landowners, this new section (orange line on map) will be underground, and within the powerline easement (where possible).

We are now starting the concept design and detailed environmental assessment for the replacement CTGM, which will take about a year to complete. This will involve additional site investigations to better understand sit conditions from mid-February 2024.

We expect the concept design and review of environmental factors will be placed on public exhibition for community feedback from early 2025.