The collapsed sewer sinkhole on St Georges Bay Rd in Auckland's Parnell. Photo / Watercare
The collapsed sewer sinkhole on St Georges Bay Rd in Auckland's Parnell. Photo / Watercare
A huge blockage at the site of a 13-metre sinkhole which appeared in Auckland’s Parnell is now halfway cleared as raw wastewater continues to flow directly into the Waitematā Harbour.
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 13m-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.
In an update today, Watercare said contractors had removed another 10 tonnes of debris in the past 24 hours and were about halfway through the blockage.
A photograph from inside blocked sewer line beneath St Georges Bay Rd in Auckland's Parnell. Photo / Watercare
It said hydro-jetting and suction to remove grit from the blockage was continuing 24/7. However, there were many large rocks in the pipe that couldn’t be removed through this technique.
“We will be reviewing how we can safely remove these rocks,” a spokesperson said.
Watercare has also removed a brick wall that was put at risk by the sinkhole and posed a health and safety risk.
The design for a bypass solution has also been completed, and Watercare expects to start laying the pipe on Monday.
The sinkhole in Parnell is the size of a tennis court, says Ōrākei councillor and Auckland Deputy Mayor Desley Simpson.
“This bypass will transfer wastewater between the two manholes on either side of the blockage, which will significantly reduce the overflows and enable repairs to the pipe,” a spokesperson said.
The spokesperson said the blockage of the pipe was caused by the sinkhole widening, which sent ground material tumbling into the pipe.
“Wastewater was still flowing through the pipe when we were first alerted to the sinkhole.
“The cause of the sinkhole is unknown at this point,” they said.
Auckland Deputy Mayor Desley Simpson earlier described the sinkhole as being “the size of a tennis court”, saying the damage was the result of severe weather and lots of rain.
During a ceremony with the support of the Taumata Kaumātua on Thursday, local iwi Ngāti Whātua Ōrākei placed a rāhui across the Waitematā Harbour.
“Due to the contamination of the waters of the Waitematā and surrounding creeks, the rāhui placed by Ngāti Whātua supports that there be no swimming, fishing, paddling, diving or entering water. Transport across the Waitematā is allowed.”
A rāhui is a cultural and formal placement of restrictions upon a place for reasons of safety or preservation.
“We are saddened and angered by the sewage overflows contaminating the Waitematā. This incident retraumatises our iwi, who were at the receiving end of the city’s sewer scheme at Ōkahu Bay for 50 years,” Ngāti Whātua Ōrākei earlier wrote in a statement.
A spokesperson from Ngāti Whātua Ōrākei told the Herald they don’t monitor the rāhui officially.
“It is up to people to refer to their own values as to whether they observe it. All Ngāti Whātua Ōrākei and Watercare can do is our best to inform the public of the danger,” they said.
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.
24 beaches across Auckland are closed due to the ongoing wastewater overflows. Photo / Safeswim
According to Safeswim, 24 beaches across Auckland are closed due to the ongoing wastewater overflows.
Over 25m of the St Georges Bay Rd sewer line was blocked, requiring “major” excavation to unclog the pipe.
Watercare earlier said it could take at least three days to unblock the damaged Central Auckland sewer pipe.
However, Bourne now says clearing the blockage “could take several weeks and the pipe’s long-term repair is likely several months away”.
