Watercare chief operating officer Mark Bourne told the Herald this evening hundreds of litres of wastewater was flowing into the harbour a second. Photo / Dean Purcell
Watercare chief operating officer Mark Bourne told the Herald this evening hundreds of litres of wastewater was flowing into the harbour a second. Photo / Dean Purcell
More than 8 million litres of sewage is pouring into Auckland’s Waitematā Harbour a day because of a collapsed sewer drain.
Watercare’s chief operations officer, Mark Bourne, said they were doing “everything in their power to put an end to the overflows as soon as possible” with an interim solution target of 10 days time.
One infrastructure and utilities expert, meanwhile, says the overflows could have been avoided if proactive checks of the city’s sewerage network had been done and any possibilities of a collapse were spotted earlier.
Luke Herlihy, with geophysical mapping company Reveal, told the Herald ground-penetrating radar technology can spot defects in underground infrastructure like pipes and alert authorities to issues before they become worse.
New photo of collapsed sewer sinkhole on St George's Bay Rd in Auckland's Parnell. Photo / Watercare
The Herald first reported the sewer line had collapsed and caused a massive sinkhole to open up, leading wastewater to pour into the harbour and close the city’s beaches on Wednesday.
The 13-metre-deep sinkhole descends to a 2.1m-wide collapsed brick pipe below a private property on St Georges Bay Rd in Parnell that serves Central Auckland and West Auckland.
Deputy Mayor Desley Simpson described the sinkhole as “the size of a tennis court”, saying the damage was the result of severe weather and lots of rain.
Bourne told the Herald this evening hundreds of litres of wastewater was flowing into the harbour a second.
Watercare chief operations manager Mark Bourne. Photo / Simon Runting
A Watercare spokeswoman clarified it was about 150 litres of sewage a second.
Calculated over 24 hours, there would be at least 8.64m litres a day draining to the harbour.
“Like everyone else in Auckland – we are saddened by this unfortunate event,” Bourne said.
“Our beautiful Waitematā Harbour is a tāonga.”
A sign at Judges Bay warns of spilling sewage after a pipe burst in Parnell. Photo / Dean Purcell
Herlihy said ground-penetrating radar be deployed from a unit driven on the street and could identify “anomalies” like missing sections or blockages in pipes.
“Then [contractors] proactively go and remediate [those issues] before things like the sinkhole happens.
“These things [faults] take time to develop over kind of two or three years. Proactive mapping and capture of Auckland’s streets would be valid for a couple of years,” Herlihy said.
“It’s not like a small void would appear under the road and then a day or two later a sinkhole appears,” he said.
Inside the blocked sewer line beneath St George's Bay Rd in Auckland's Parnell. Photo / Watercare
“You’d be able to identify quite small anomalies, as small as half a foot [about 15cm], and then a year or two later you might scan streets to do the same thing again.”
While Herlihy admitted some infrastructure failures couldn’t be avoided, he said: “We shouldn’t have to deal with disruption like this.
