About us.

Discover what makes OneStone unique.

OneStone is a leading water system consultancy that assists clients in planning, designing, operating and testing efficient water systems.

By using a holistic approach, we positively impact our clients, communities and the environment through the development of innovative and sustainable water solutions.

Our vision, mission
and objectives.

Find out how we aim to become WA’s leading water systems consultancy and thought leaders for our industry.

Read about what drives our pursuit of more efficient and sustainable water systems.



The values that mean our culture really is dynamic.

We can prove our culture is more creative, collaborative and therefore effective than traditional water systems consultancy models. It’s in our approach, our solutions and our three core values.


We do the right thing. Always. We do what we say we will do. And we never compromise our ethics for profits.

We exceed expectations because we love what we do. We thrive on the challenge of solving problems and making a positive difference to business, communities and the environment.

We challenge the norm, constantly. We relentlessly pursue better, more efficient, more sustainable solutions and ways of working together.


Our people and culture

Meet our founder Eelko, whose passion for engaging the logical left-brain with the creative right-brain to analyse and solve complex water engineering challenges is at the heart of OneStone. 

Eelko Van Der Vaart

Master of Science in Civil Engineering, Delft University, the Netherlands (specialising in Environmental Engineering and Water Management)

Leaving the Netherlands in 2005, where he developed his expertise in water management and control systems, Eelko came to WA where he applied his highly transferable knowledge and design skills to an increasingly diverse range of water management and distribution projects. In 2010, he established OneStone with the mission to support clients in sustainably managing our state’s most precious resource by employing a creative, integrated approach to water system design.

Eelko’s passion for water management is born out of his insatiable appetite for analysing complex problems. He loves the dynamic nature of water and the inherent complexities of water systems, which give him the opportunity to combine his scientific knowledge with his creative design and engineering skills. And when he isn’t working tirelessly to find new and better ways to manage water, you’ll find him indulging his other water-based passion – surfing at Trigg Beach.