Watercare Making Steady Progress On Solution To Harbour Overflows

Watercare is making steady progress on its emergency work to build a bypass pumping solution that will transfer wastewater from the manholes on either side of the Ōrākei main sewer sinkhole and pipe blockage site.

The bypass is an essential component of the work to end or significantly reduce wastewater overflows into the Waitematā Harbour as soon as possible.

Watercare head of service delivery Sharon Danks says an important milestone was reached today with the installation of a ‘stoplog’ at a manhole near the sinkhole site.

“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.

“Excavation of the chamber that will house the temporary pump station is continuing. We encountered some concrete piles during this excavation, which slowed work a little. 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.

“At this stage we’re on track to have the bypass operational on October 17 but we are working to a really tight programme. Our twin priorities are reducing the overflows as soon as possible, while protecting the safety of our staff, contractors and the public.

“We’re all looking forward to having the bypass operational as soon as possible. This work is fairly disruptive for the local business community, but we’re managing to keep vehicle and pedestrian access open.

“We’d like to thank everyone for their patience while we’re doing everything we can to end the overflows into the Waitematā Harbour as soon as possible.”

When the bypass is operational, Watercare expects it will end or significantly reduce the overflows. As some of the catchments that feed into theŌrākeimain sewer are historic combined wastewater and stormwater networks, the flow in the sewer increases in wet weather and decreases in dry weather. 
 
“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,” Danks says.

Watercare incident controller Nigel Toms says Aucklanders are still urged to avoid swimming, fishing and recreational activities in the inner Waitematā Harbour.

“Please check the Safeswim website for the latest advice before venturing into the water.

“Auckland Council’s Safe Networks team is monitoring beach water quality with an extensive sampling programme in the inner harbour.

“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.”

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