A main Auckland sewer line has collapsed, causing a massive sinkhole to open up, with wastewater overflow pouring into the harbour and closing the city’s beaches.
Video / Desley Simpson
Auckland’s water authority says it is making progress on a temporary solution to a blocked sewer main, aiming to complete a bypass in a week’s time. Meanwhile, sewage continues to pour into the harbour.
The 13-metre-deep hole descended to a 2.1m-wide collapsed brick pipe below a private property on St Georges Bay Rd in Parnell that served Central Auckland and West Auckland.
However, even after the bypass is built, sewage could continue to pour into the harbour during wet weather because wastewater flows increase when it rains.
A diagram showing the impact of the Parnell sinkhole on the Ōrākei main sewer. Photo / Watercare
An important milestone was reached today with the installation of a “stoplog”, Watercare head of service delivery Sharon Danks said.
“The stoplog is basically a steel fabricated door that seals the sewer and prevents wastewater from entering the blockage site.
“It’s an essential component of the bypass project but it also means that, when we are in a position to finish clearing the blockage, we can do so safely – without a wall of wastewater on the other side.
“The crews on site have also been working incredibly hard on the other parts of the project. We’ve laid about two-thirds of the pipe now, up St Georges Bay Rd and through Alberon Reserve.”
She said the underground area where the pumping station would go was still being excavated, with concrete piles slowing work.
The sinkhole on St Georges Bay Rd in Parnell. The broken sewer pipe served central and west Auckland. Photo / Supplied by Watercare
“It’s a big job – we’re effectively making space for a two-storey house underground, with the added complication of other services that need to be relocated.”
She said Watercare should finish the bypass by October 17, “but we are working to a really tight programme”.
Danks acknowledged the work was disruptive, but said vehicle and pedestrian access on St Georges Bay Rd remained and she thanked the public for its patience.
“It is likely that, in wet weather, there will be some overflows even after the bypass is in place – but the volume of these would be much smaller than we’re seeing now”.
Watercare chief operations officer Mark Bourne told the Herald hundreds of litres of wastewater were flowing into the harbour every second. Photo / Dean Purcell
Watercare incident controller Nigel Toms said Aucklanders still shouldn’t go swimming, fishing, or engage in any recreational activities in the inner Waitematā.
He said Auckland Council’s Swimsafe was monitoring beach water quality with an “extensive” sampling programme.
“We’ve also engaged a team of marine environmental experts to develop a monitoring programme so they can fully assess any impacts on the Waitematā Harbour once the overflows have stopped.”
All beaches south of Cheltenham and west of St Heliers remain closed.
