Low-carbon stormwater pipe being installed in central Auckland on 9 October 2023. Photo: RNZ / Lucy Xia
A new low-carbon stormwater pipe being installed today at the site of a sinkhole in central Auckland is the first of its kind in New Zealand.
In July, a 2.5 metres wide sinkhole appeared on College Hill Road, after a stormwater pipe burst beneath the busy thoroughfare. It is just one of a string of recent issues with Auckland's ageing water network.
The new pipes are hoped to help reduce the city's carbon footprint while also preventing future problems.
The gaping sinkhole in Freeman's Bay is among more than 30 to have appeared in the city since the weather events earlier this year.
Today Auckland Council contractors began laying low-carbon concrete pipes at the site, which create 22 percent lower emissions than traditional concrete pipes during construction.
With concrete being one of the greatest contributors to Auckland Council's carbon footprint, Healthy Waters general manager Craig Mcilroy said this could have a significant impact.
The $2.86 million College Hill project will see 300 metres of pipe laid from Beaumont Street and Victoria Street West to England Street, and is estimated to have avoided 4.4 tonnes of CO2 emissions.
Craig Mcilroy. Photo: RNZ / Lucy Xia
Pipes company Hynds manufacturing manager Josh Siataga said the emission reduction was achieved through the materials the pipes were made from and their design.
"Using cementitious products to produce a lower carbon footprint, as well as sourcing some of our materials, so the aggregate and steel, from suppliers that are on the same journey in terms of their sustainability framework," he said.
Mcilroy hoped these low-carbon pipes could be more widely used in the stormwater renewal programme that's currently under way.
He said there were about 60km of stormwater pipes in the city that were more than 100 years old and needed to be replaced within five years.
The burst pipe at College Hill had been flagged as of the highest risk category and requiring replacement, before the incident in July, he said.
Low-carbon stormwater pipe being installed 3.5 metres deep in central Auckland on 9 October 2023. Photo: RNZ / Lucy Xia
A total of 1200km of pipes in Auckland are deemed "critical" and are being evaluated for their risk, where some will be repaired and others will be replaced within the next five to ten years - estimated to cost $200 million.
Mcilroy said those pipes were in areas where any damage could affect higher numbers of people.
Meanwhile, businesses in the area that had already dealt with months of traffic controls are frustrated that the project will take until late December to finish.
Tony Chase, the owner of a motorcycle gear store on College Hill, says it had been impacted for most of the year, with some pipes bursting earlier this year following Cyclone Gabrielle.
"We're not overjoyed, because we've got more disruption in the busiest time of the year, we're a seasonable business and we rely on our summer trade, and going into Christmas," he said.
Harry Williams, the manager of a streetwear store facing the pipe construction area feels the same.
"It's been all year, it's been really slow, and I think it's kind of blocking up everything for the whole city,
"It's probably one of the main streets that people travel through," he said.
Williams said the basement was flooded in the January floods, and it lost about $100,000 worth of stock. He said they've also had to deal with the stench of a burst sewer line earlier this year.
Harry Williams pointing to the height at which the store basement got flooded in the January deluge. He estimates losing about 40 customers a day. Photo: RNZ / Lucy Xia
Meanwhile, wastewater pipes in Auckland, managed by Watercare, are also requiring significant repairs.
Watercare has started its search for businesses to partner with for a decade-long $3.5 billion programme to replace ageing wastewater pipes and upgrade pump stations and treatment plants.
