New water treatment plant near Tuakau about to go live

Aerial view of Watercare's new water treatment plant in Tuakau

Our new water treatment plant by the Waikato River will go into service this afternoon, providing up to 50 million litres a day and marking a critical milestone in our drought response.

The ‘Waikato 50’ plant has been designed and built in under a year in response to Auckland’s drought. The new plant sits alongside Watercare’s existing plant near Tuakau.

Auckland Mayor Phil Goff welcomes the additional water supply: “The extra 50 million litres a day provided by this facility is the latest in a series of measures introduced over the past year which together will give us an extra 106 million litres a day by the end of next summer. That’s enough to supply an additional 330,000 people - equivalent to around twice the population of Hamilton city,” he says.
“The Waikato 50 facility was built in record time and is one of the most sophisticated water treatment plants in the country. It significantly increases Auckland’s water resilience, which is critical as we continue to experience lower-than-normal rainfall.
“Three drier-than-normal years in a row and the need to be climate-change resilient means that as well as increasing supply it is also important that Aucklanders keep up their water-saving efforts, which have saved more than 20 billion litres of water since restrictions began in May 2020.”

Chief executive Jon Lamonte says the new plant will provide a welcome safety net if the weather turns out to be drier than forecasters expect.

“At the moment, forecasters are predicting a normally-wet winter and a slightly drier-than-normal spring. Our Waikato 50 plant provides a bit of extra security in the event the weather turns out to be much drier than predicted over a prolonged period.

“Building another Waikato plant has been on our agenda for more than a decade as part of our plan to meet Auckland’s growing population – but we’ve built this Waikato 50 plant in response to drought. Our plan, if we obtain the necessary consents, is for this plant to be adapted and expanded to become our Waikato A Water Treatment Plant.
“It would be expanded in stages – timed to meet population growth – until it can ultimately treat up to 150 million litres a day. To put that into perspective, it’s significantly more water than we get from our five dams in the Waitākere Ranges combined.”

The completion of the Waikato 50 plant takes our peak production from the Waikato River to 225 million litres a day.

A new pump station in Papakura has also been built to enable the pipeline to deliver that amount to Auckland, via the Redoubt Rd storage reservoirs.

The treatment plant uses ultra-filtration and membrane technology to turn the river water into top-quality drinking water.

Lamonte says the Waikato River is the best option to meet Auckland’s water needs over the next two decades as the city’s population and economy grows.

“Before we applied for resource consent, we assessed more than 150 other potential water sources that could be developed to meet Auckland’s demand requirements over the next 35 years. Through this process the Waikato River became our preferred option.

“One of the clear benefits is it is more resilient to drought, which is very important given our climate is changing. The Waikato River has a catchment area spanning more than 14,000 square kilometres, whereas our dams in the Hūnua and Waitākere Ranges have a combined catchment of just 158 square kilometres. This means the river is a lot less reliant on rain falling in specific locations.”