From 1 July, Aucklander's water bills will go up. Photo: CRISTINA PEDRAZZINI/SCIENCE PHOT
*This article has been updated to provide additional context from Watercare.
Aucklanders will be footing the bill to upgrade water services, including a more than $1 billion treatment plant replacement.
From 1 July, Aucklander's water bills will go up to fund $13.12 billion in infrastructure upgrades across the city.
In a plan released on Wednesday, Watercare said it would embark on 1000 projects over the next ten years in an effort to make the city's water network fit for purpose.
The most costly project would be replacing the ageing Huia Water Treatment Plant in the Waitākere Ranges, increasing its capacity, and building two new reservoirs and two new water mains.
The price tag for that had increased from $420 million to $1.12 billion since construction costs were first estimated in 2018.
Infrastructure New Zealand's Michelle McCormack said upgrading assets like the Huia Plant was crucial to meet the city's future water requirements.
"Auckland is a massively growing city and this is just the investment that is required to have a world-class system.
"A new water treatment plant at Huia will be a game changer. As a country, we have high expectations for water quality and treatment and a new plant will enable Auckland to meet these standards."
But Auckland councillor Shane Henderson said it was alarming the cost of upgrading the plant had increased so much.
"Aucklanders need an explanation as to why we're looking at something over one billion dollars.
"I've asked for a briefing with Watercare officials and they've agreed to that. I expect them to appear before the council to break down this cost and justify where it's all going and what has happened.
"We avoided a 25 percent water bill that would have been huge for people. But at the same time, water bill increases directly affecting people's cost of living and their kitchen table."
But he said not replacing the roughly 100-year-old plant was not an option.
"If we run down our assets and don't stay on top of things, we create huge problems for ourselves and huge water bills down the line."
He acknowledged factors cited by Watercare including the global pandemic, high inflation, and extreme drought and flooding in the region had driven up costs in the past seven years.
Watercare chief executive Dave Chambers said costs had increased as Watercare better understood the requirements to deliver the project.
He said the $420m figure was an estimate and did not include an additional $300m for necessary tunnels, pump stations, bridges, and watermains.
He said new infrastructure needed to be resilient and built to withstand severe weather events.
"We are confident that the current estimate of $1.12 billion to deliver the programme, which includes the treatment plant, two reservoirs, and two water mains, is realistic and represents good value for Aucklanders.
"The plant will meet approximately 20 per cent of our region's water needs, making it critical infrastructure for our community. The existing plant is over 100 years old and is reaching the end of its life."
Construction at Huia was set to begin in 2028 and be completed in 2033.
