Project benefits

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 high pressure, buried, gas transmission pipeline approximately 51 kilometres in length. It addressed 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 delivers 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) forecast that Victoria may have faced natural gas shortages by 2023.

The Western Outer Ring Main helps 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.

Pipeline route

APA refined the pipeline alignment in consultation with relevant government authorities and affected landowners.

Minimising environmental and community impacts associated with the construction and ongoing operation of the pipeline were key considerations in determining the alignment.

Wherever possible, the pipeline was co-located with existing or proposed infrastructure corridors to minimise impact on current and future land use.

The alignment also maximised the use of APA’s existing pipeline easements.

Key design parameters

The Western Outer Ring Main will be constructed as 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 occupy 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.


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.