Project benefits


The Project will present a number of benefits, including:

  • Increasing the amount of natural gas that can be stored for times of peak demand.
  • Improved network performance and reliability.
  • Addressing potential gas shortages as forecast by the Australian Energy Market Operator in the March 2020 Victorian Gas Planning Report Update.

Natural gas is an essential source of energy for Victoria, with approximately 2 million customers using gas every day for domestic applications including cooking, heating and hot water. Gas is also a critical fuel for approximately 60,000 industrial and commercial users throughout Victoria including manufacturers, and gas-fired power generation plays a key role in ensuring a reliable electricity network. In Victoria, the Victorian Transmission System (VTS) is owned and maintained by APA and consists of over 2,200 kilometres of gas pipelines.

The Western Outer Ring Main project is a proposed high pressure, buried, gas transmission pipeline approximately 51 kilometres in length. It will address a key capacity constraint in the VTS by providing a new high pressure connection between existing sources of natural gas supply in the north and east with those in the west of the state.

Addressing this missing link will deliver improved network reliability by increasing the amount of gas that can be stored for times of peak demand and ensuring sufficient volumes of gas can be moved where it is needed most. Importantly, without the project being delivered, the Australian Energy Market Operator (AEMO) has forecast that Victoria may face natural gas shortages by mid-2022.

The Western Outer Ring Main will help to deliver sufficient gas to Victorian homes for heating and cooking on very cold days, as well as supplying gas for power generation during times of peak electricity demand. The project also provides the opportunity for new growth suburbs on Melbourne’s urban fringe to be supplied with gas as those areas are developed.

The Western Outer Ring Main project will ensure that all Victorians can continue to benefit from a reliable gas transmission system that meets the needs of the community both now and into the future.

APA has developed a project information sheet that introduces the Western Outer Ring Main project, as well as a more detailed brochure that introduces APA and provides a range of relevant information for landowners and other stakeholders.

Pipeline route

APA has identified a preliminary alignment for the pipeline based on assessment of key constraints such as environmental values, cultural heritage, terrain, existing and proposed infrastructure corridors, watercourses, and land use. Initial consultation was undertaken with relevant local governments in order to ensure that community issues were understood and taken into account.

You can download and read a map of the proposed pipeline alignment. 

The preliminary pipeline alignment has sought to minimise impacts on individual properties by following existing pipeline easements, as well as the proposed Outer Metropolitan Ring transportation corridor that has previously been identified for reservation by VicRoads / Department of Transport.

Key design parameters

The Western Outer Ring Main is proposed to be a 500-millimetre diameter high pressure gas transmission pipeline. The pipeline will be constructed from high-strength steel line pipe with an external epoxy coating and be buried for its entire length to a minimum depth of 900 millimetres.

APA will be seeking a 30-metre right of way to construct the pipeline. After the completion of construction, the pipeline will occupy a permanent 15-metre wide easement. Temporary access is required to an additional 15 metres of construction workspace so that the pipeline can be constructed safely and efficiently.

Construction 'right of way' diagram


All gas transmission pipelines in Australia are designed, constructed, tested, operated and maintained in accordance with Australian Standard (AS) 2885 – Pipelines – Gas and Liquid Petroleum. This standard puts public safety at the forefront of decision making and ensures the safety of communities, protection of the environment and security of supply to gas users.