Why Diona?

Enabling Communities to Thrive

John In Excavator Bw 2
Dsc 0181 3 Group Photo
Vince Barry July 2002 Cropped

From humble beginnings

John and Margaret O’Connor founded Diona in 1980. Since then the company has grown to become one of the most respected engineering companies in Australia with over 500 employees.

Our specialty is technically complex urban projects. We have a proven track record of developing equipment and innovative solutions to meet challenging client requirements.

We've got you covered

Diona is set apart by our comprehensive ‘one-stop’ service offering and single point of accountability for all of your utility and infrastructure needs.

We offer a true turn-key solution covering all aspects of design and construction encompassing trenching, drilling and pipeline installation for water, drainage, sewer, gas, electricity and transport infrastructure.

We are accredited service providers to Energy Australia, Energex, TransGrid, Sydney Water, Queensland Urban Utilities, Brisbane Water, APA, Jemena, and Telstra, as well as many other asset owners. We’ve also worked on many projects for local councils in the greater Brisbane, Sydney and Adelaide regions.

A hands-on approach

In the complex (and potentially expensive) world of infrastructure delivery – the price of an on-time, hassle-free project delivery is hard to put a figure on. For us (and our clients), it equates to value.

At Diona, we pride ourselves on our ability to self-perform. With a range of skilled personnel and specialised plant, we have the flexibility and depth to deliver complex infrastructure projects and react quickly to changes in scope.

We approach every project collaboratively engaging with our clients, stakeholders and the community from start to finish. We feel that an open dialogue and complete transparency does, in fact, translate to fewer headaches, less room for error and much smoother project scheduling. In turn, this means lower costs and fewer delays.

Moreover, we believe our approach translates to a safer project and every single Diona employee, from Excavator Operator to Executive General Manager, live and breathe a safety-first culture. Our workforce is well-trained in workplace health, safety and environment management.

Constantly evolving through innovation

We know our clients are under pressure to complete projects on time and within budget. That is why we are constantly evolving our design techniques, delivery methods and technology offering to complete projects quicker, more cost effectively and with less environmental and community impact.

Experience you can rely on

There is no substitute for experience, and Diona has it. After more than 41 years in operation, our depth of knowledge and experience is extensive. Furthermore, many of our people on site and in the management team have been with us for ten years or more and are highly skilled in their field of expertise.

Enabling Communities to Thrive


Despite these works being carried out under difficult conditions and at night, your team worked closely with SWC and WCG to complete these works safely with minimal disruption and inconvenience to the surrounding businesses and the general public.
C. Heath, Program Director, Stage One Project Team on the Sydney Water Trenching Works, George Street Liverpool
Well controlled project, the company displayed ability to co-ordinate multiple worksites and address unforeseen conditions or variations with minimal program effect.
Phil Stone, Project Engineer, Wallacia Priority Sewerage Program - Wallacia on the Energy Australia Merewether Substation to Newcastle CBD 33kV Feeder Project
I would not hesitate in considering Diona for future works. Their performance was consistent and they were committed to complete the project as required.
S.Davin, Project Engineer, Priority Sewerage Program Team on the Trenching and Installation of approx 3.5km 150-225mm dia pvc gravity sewer mains works.
On behalf of Water Operations Treatment, we wish to thank the Sydney Water Team and Agility Team for managing the environmental impacts of the project with absolute commitment and dedication. We have not received a single complaint from our customers and stakeholders since we commenced construction. We also wish to thank SCA and National Parks for their contribution in the development and management of the REF. Thanks to Rebecca Irvine (Diona Environmental Manager) for your close supervision of the project.
Sri Srianandarajah, A/Team Leader Water Operations Treatment, Water Filtration on the Cascade Water Filtration Plant to Greeves Creek System, Katoomba Project