Sinkhole opens up in St Marys Bay, Auckland; street cordon erected around crater

A sinkhole has opened up on a street in one of Auckland’s oldest suburbs, with a protective cordon now in place to prevent traffic from driving near the crumbling road.

Fire and Emergency New Zealand staff are on the corner of Dunedin and New Streets in St Marys Bay to keep people safe and away from a sinkhole that opened up at lunchtime.

A firefighter told the Herald the council was responsible for fixing it, but Fire and Emergency were on the scene to put down cones and keep people away.

A sinkhole has a brick-lined crater that is around 2sq m beneath the ruptured surface of the St Marys Bay street. Photo / Michael Craig

The firefighter said it would be easy for a motorist or cyclist to hit the sinkhole if they had not put cones around the hole.

The hole is about 50cm wide, but a firefighter said there was a larger void under the surface.

There is an area of about 2sq m. He said people should not stand on, lest the ground gives way.

The chasm has revealed extensive brickwork beneath the road.

Firemen look down into a sinkhole opened up on the corner of Dunedin and New Streets in Auckland's St Marys Bay. Photo / Michael Craig

The surrounding streets are very quiet, but traffic can continue to drive around.

Auckland Council said its healthy waters team has contractors on the way to determine the cause of the hole and Auckland Transport has made the site safe by placing a plate over the hole.

“Healthy waters will be determining the best course of action for repair. An engineer will also inspect the site before remedial action is taken,” a spokesperson said.

While the cause of the sinkhole was unclear, large hollows elsewhere in the city in the past two years have been blamed on deteriorating pipes and high rainfall.

In September 2023, a 13m-deep hole on St Georges Bay Rd in Parnell opened to a 2.1m-wide collapsed brick pipe that served Central Auckland and West Auckland.

About 150 litres of sewage a second flowed into the Waitematā Harbour at the time. Calculated over 24 hours, there would be at least 8.64 million litres a day draining to the harbour.

Watercare released findings of a report six months later with the council organisation apologising profusely and promising to work on rebuilding its sewer network.

The report said the condition of the pipe, weakened concrete blocks at the sinkhole’s location, excavation for a power cable nearby and corrosion and erosion led to the chasm opening up.

Another sinkhole on College Hill appeared months earlier in July 2023 when a stormwater pipe cracked and led groundwater to seep in during heavy rain events.

Earlier still, another sinkhole occurred on the same pipe a bit further down College Hill near the corner of Victoria Park during the January 27, 2023 floods. This sinkhole, on a busy intersection, was quickly filled in.

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