APA Group

Seaford – Aldinga Augmentation


Gas pipeline

Contract Type


Year of Completion




Advancing Energy Accessibility for Adelaide’s South

Enhancing the gas network to accommodate the increasing energy needs of Adelaide’s southern suburbs, the project plays a vital role in ensuring access to safe, reliable and sustainable energy services for residential and commercial customers.

Project Overview

APA Group engaged Diona to deliver Stage 3 of the Seaford – Aldinga augmentation, and upgrade to the high-pressure network, guaranteeing a lasting gas supply that will keep the southern suburbs of Adelaide thriving for years to come.

Project Need

The gas network in the Seaford – Aldinga regions caters to 15,000 residential and commercial customers. However, with increasing demand anticipated to surpass capacity, a need for expansion and enhancement of the network was required.

Project Solution

Diona constructed 3.3 kilometers of DN300 steel transmission pressure main and DN280 high pressure PE main, enhancing capacity for future demand. Despite the complexities of the project, Diona’s comprehensive consideration of environmental requirements, client expectations for quality, time, and budget,  and rigorous safety standards, ensured successful delivery of the project.

Operating along the Onkaparinga River bank and within the Onkaparinga Recreational Park introduced diverse technical and environmental challenges. Noteworthy was the successful installation of a 300mm steel main beneath the Onkaparinga River using horizontal directional drilling.

Value Add | Benefit
Industry Recognition

The project achieved notable success, earning recognition through the prestigious South Australia CCF Earth Awards 2017 in Category 1 (project value up to $1 million).

Efficient Construction Solutions

Challenging ground conditions, including soft soil and large cobbles, complicated the implementation of APA’s design. Collaborating closely, Diona and APA devised a new design and construction method to overcome these challenges, successfully completing the underbore using 12-meter steel pipeline segments connected through welding, sandblasting, and joint coating.

ESG Alignment

Thoughtful attention to environmental factors, especially the complexities arising from the project’s proximity to the Onkaparinga River and its location within a recreational park, underscores the significance of environmental protection in the course of infrastructure initiatives.

By upgrading the gas network to meet the growing energy demands of Adelaide’s southern suburbs, the project contributes to ensuring access to reliable, sustainable, and modern energy services for both residential and commercial customers.

The construction of the gas main, especially the technical challenge of directional drilling under the Onkaparinga River, showcases innovation in infrastructure development. This kind of innovative engineering solution is essential for building resilient infrastructure.

Enhancing the gas network capacity ensures that the rapidly growing Seaford-Aldinga regions can sustain their development while maintaining a reliable energy supply, crucial for the overall quality of life and economic growth in these communities.

The project’s careful consideration of environmental aspects, particularly the challenges posed by its location near the Onkaparinga River and in a recreational park, supports the importance of protecting and restoring terrestrial ecosystems during infrastructure projects.

The collaboration between Diona, APA Group, and other stakeholders in overcoming the technical and environmental challenges highlights the significance of partnerships in achieving infrastructure development goals sustainably and responsibly.

Industry Award

Winner: Category 1 (project value up to $1 million)