Pipeline construction in southern NSW, Jan 2017

APA Group is progressing plans to build a 461 kilometre pipeline - the Western Slopes Pipeline - to connect a new supply of natural gas from Santos’ proposed Narrabri Gas Project to the New South Wales gas transmission network, via the Moomba Sydney Pipeline. The Project has the potential to play a key role in helping NSW achieve greater energy security into the future, which is ultimately good for consumers.

The Western Slopes Pipeline will have the capacity to transport up to 200 terajoules of natural gas per day. That is the equivalent of around 50 per cent of the current daily natural gas needs of NSW homes, small businesses, major industries and electricity generators. NSW currently produces just 5 per cent of its daily gas demand, a figure that will soon be reduced to zero with the planned closure of the Camden gas project.

Key design parameters

The pipeline will be constructed from high-strength steel line pipe with an external epoxy coating. The diameter of the pipeline will be selected during detailed design but based on the required capacity is likely to be in the range of 400-450mm (16-18”). The EIS for the project will be assessing a 508mm (20”) pipeline in order to build conservatism into the assessment. 

The pipeline will be buried for its full length to a minimum depth of cover of 900 millimetres. Additional depth, 1200mm or greater, will be required at infrastructure and watercourse crossings.

A small number of surface facilities will be required at 5 or 6 locations along the pipeline. These facilities, known as Main Line Valves and Scraper Stations will allow us to operate and maintain the pipeline safely. An offtake station and delivery station, at the start and end of the pipeline respectively, will also be required. No compressor stations are proposed along the pipeline.

A 30-metre wide easement will be sought to provide adequate space for topsoil management, vehicle movements and stringing of the pipeline during construction. After construction, normal agricultural operations can resume within the easement.

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.