Earlwood to Summer Hill cable project

Earlwood to Summer Hill cable project - a similar cable project 
Ausgrid is planning to replace underground electricity cables that run between our substations at Earlwood and Summer Hill. The existing 33,000 volt cables are nearing the end of their service life and need to be replaced so Ausgrid can maintain a safe and reliable power supply to the area in the future.

Project need

The existing 33,000 volt underground cables are nearing the end of their service life and are to be replaced.  The cables are connected to a substation at Summer Hill (known as Dulwich Hill zone substation) which Ausgrid is also planning to replace with a new facility next door.

The existing substation and cables have been in service since 1966 and are a key part of the electricity network supplying power to Summer Hill and surrounding suburbs. Ausgrid constantly monitors its infrastructure and has identified the need to replace the cables and substation in the coming years before they become unreliable.

Planning cable projects

As Ausgrid plans this project, there area number of factors to consider, including:

  • community impacts
  • availability of space around existing utility services
  • environmental and heritage impacts
  • cost (minimising the impact on electricity bills)
  • technical feasibility
  • traffic impacts
  • crossing Cooks River and the Bankstown railway line.

Project status

Initially Ausgrid's planning focused on potential ways to cross the Cooks River and the Bankstown Line railway as this would have a significant influence on the potential cable routes.

Potential options for these crossings included boring underneath the river or attaching the cables to existing bridge structures. A range of initial route options were developed for further investigation and Ausgrid began consultation with the then Canterbury Council (now Canterbury-Bankstown Council).

Ausgrid investigated these routes with consideration of a range of factors (see the 'Planning cable projects' section above) and further consulted with Council. Following this process, Ausgrid refined the potential routes to a number of feasible options for community feedback.

Community information sessions were held on 21 June and 23 June 2016  to let people find out more about the project and to provide feedback on the potential route options. All feedback has been considered by the project team as part of the process to prepare a proposed route for environmental assessment and for further consultation. A summary of the feedback from the sessions and from direct contact with Ausgrid can be viewed via the link at top right.

Following this process, Ausgrid now has a preferred cable route - see community newsletter at top right for more information. An indicative timeline of key dates can be viewed via the link the right of this page.

Project approval process and environmental assessment

Under the Environmental Planning and Assessment Act 1979, Ausgrid is the determining authority for this project. An environmental assessment (known as a Review of Environmental Factors or REF) would be prepared on the preferred cable route option in accordance with Part 5 of the Environmental Planning and Assessment Act 1979 and Clause 228 of the Environmental Planning and Assessment Regulation 2000.

The REF will include a range of specialist studies and input from the community, councils and other authorities. The REF investigates the potential environmental impacts associated with the construction, operation and maintenance of the proposed cable route. It also recommends mitigation measures as required to ensure any impacts are at acceptable levels.

The REF will go on public exhibition to provide an opportunity for interested community members to make a submission. After consideration of community comments, Ausgrid will then assess the project for construction approval.

Community engagement

On 21 June and 23 June, 2016, Ausgrid held two information sessions, one at the Canterbury Hurlstone Park RSL Club and the other at the Ashfield Civic Centre, to seek local information and community feedback on potential cable routes. Interested community members were invited to the workshop directly through newsletters, social media and advertisements in local newspapers. 

At the community information sessions, members of the project team gave two presentations -  on project need and what to expect during construction of a typical underground 33,000 Volt cable project.  These presentations can be viewed via the link at the top right hand side of this page. 

A summary of feedback from the community information sessions can be viewed by the link at right. This report is a summary of feedback received at the information sessions and via direct feedback to Ausgrid after the sessions. Community feedback has been considered by the project team as part of the process to refine the options to a proposed route and to plan the project to minimise impacts during construction.

To find out more or to provide feedback to Ausgrid, please get in touch via the contacts on the right of this page. Ausgrid welcomes feedback throughout all stages of the project.

What to expect during construction

Like any construction work, the project would involve noise and dust, and temporary traffic and parking disruptions, which we would work to reduce as much as possible. Any potential impacts are assessed as part of an environmental assessment (known as a Review of Environmental Factors or REF) and measures would  be put in place to minimise impacts on the local environment.Click here to view an information graphic showing the stages of cable laying. Construction would include:

  • digging trenches, typically 800mm wide, to lay conduits (plastic pipes) to hold the new cables
  • filling trenches and resurfacing the area temporarily
  • trenching and temporary restoration of affected areas takes about three days outside each property depending on ground and weather conditions
  • excavating underground joint bays every approximately 900 metres along the route in the road to feed in and join sections of cables together
  • feeding in and joining the sections of cables takes two to four months to complete at the joint bays
  • work on the joint bays usually occurs in distinct stages
  • final restoration of affected roads and other areas in consultation with council.