Local Focus: Inside Tauranga’s new water treatment plant

Described as a ‘once in a generation’ asset, Tauranga’s new Waiāri Water Treatment Plant has been 16 years in the making.

“Back in the late ‘90s, there was pressure on the amount of water being supplied to the city,” Tauranga City Council water services manager Peter Bahrs said.

“People were demanding more water, and the council was looking for alternative water sources.”

The plant was meant to be built by 2015, but the council halted development in 2012 blaming the global economic crisis. Four years later the project was resurrected, and construction began in 2018.

But the opening of the new plant doesn’t mean an end to Tauranga’s annual water restrictions.

“We’ve just seen the effects of climate change; we’ve had three dry years [then] an incredibly wet year, so we’ve got to manage that reality of climate change,” Bahrs said.

“We’ve also got to balance it with the reality of the environmental requirements. That’s our primary focus, in terms of getting that balance right and ensuring that we meet the community needs for the future.”

When asked about the community’s current needs, Bahrs said the plant was already supplementing the community’s needs.

“We want to keep the water conservation messaging going and have people buy into water conservation for the long-term. If we can continue to get people using water wisely, that will help this generation, as well as future generations.”

One local raised questions at the plant’s opening ceremony about the Waiāri’s sustainability.

“I challenged all the speakers,” Rosina Anne Reokore Potiki said.

“They all mentioned that this plant makes the water – it doesn’t. The water comes from the Waiāri, it’s part of the mana whenua.

“I’m really worried that although they say they acknowledge the life source of the Waiāri, I don’t believe them. They’re thinking 30 years; the Waiāri’s been there for thousands of years.”

As seen recently, severe weather events can have a devastating impact on a city’s infrastructure, even leaving residents without fresh, clean water.

Bahrs said many variables had been taken into consideration when designing this new facility.

“We know the catchment area is very steep, prone to landslips, the river levels rise very quickly during significant rain events and the water dirties up significantly as well, so all those things have been built in.

“In the event that we have a volcanic ash fallout, we’d hope that the clarification process would take a lot of that out of the mix and that the membranes would still be providing safe water for the city.”

Rodney Clark, water treatment manager at Tauranga City Council's new Waiāri treatment plant, explains how membranes work.

It’s these special membranes that stand between you and bugs in your drinking water.

“A membrane is essentially a filter. It’s made up of 9000 straws and the straws are micro-porous,” the council’s water treatment manager Rodney Clark said.

“It’s made up of tiny little holes that allow clean water to pass through, but stop the bugs from going through.”

Bahrs said the council is always looking to the future and considering where the city’s next source of water will come from.

“Our existing water take consents for the Tautau and Waiorohi, which feed our Joyce Road and Oropi treatment plants – they come up for reconsenting in 2026.

“Depending on the allocation of water that we get, through that reconsenting process, that might have a direct impact on when we look for a future source of water for the city.”