One of the largest civil engineering projects in the history of Whangārei District Council, the new Whau Valley Water Treatment Plant is designed to future-proof the urban water supply for the community in the growing Whangarei District region in northern New Zealand, which enjoys some of the best drinking water in the country.

The scope of works saw Ventia replace and fully upgrade the existing 50-year-old Water Treatment Plant in Whau Valley. The previous facility no longer met structural building code requirements and could not be brought up to current New Zealand standards at a reasonable cost.  

The new $30 million Water Treatment Plant was relocated to a large greenfield site nearby the dam on Whau Valley Road in order to accommodate growth and support the District well into the future.

The new Water Plant will increase the water supply, from 15,000 cubic metres processing to 22,000 cubic metres or 22 million litres a day from the Whau Valley Dam and the Hatea River, enabling access to an additional 7 million litres for the growing local community. 

The new plant features the latest technology including a state-of-the-art filtration system and a Hydro Generator, which utilises dam water supply to run the turbine and provide energy to run parts of the plant.

With a range of skills and expertise required onsite to complete the works, effective Teamwork was fundamental to productivity and delivery. A full Ventia project management oversaw end-to-end construction.

Whau Valley WTP

Collaboration with Whangarei District Council 

At the beginning of the Project, Whangarei District Council and Ventia invited all subcontractors to join them and unite behind a statement of intent: 

Safely delivering a healthy reliable water supply for our community through effective communication, quality construction, trust and teamwork.

This set a benchmark for open communication, trust and teamwork, receiving positive feedback from the client.

Whangarei Heads

Overcoming challenges 

When New Zealand's level 4 lockdown hit in March-April 2020 due to the COVID-19 pandemic, site access was restricted, and the project momentarily hit pause. The team continued to maximise their time to plan and prepare, so that onsite works could restart and continue smoothly as soon as possible, in line with new COVID-19 regulations.

Works were completed at the end of 2020 with commissioning taking place over several months in 2021 to ensure that all parts of the treatment process are working well together.

Community outcomes

The new Water Treatment Plant provides a reliable and resilient water treatment processing facility to support the future expansion of the Whangarei district.


Watch our video to learn more