Sinkhole reopens old wounds on Auckland’s St Mary’s Bay street

A large sinkhole has opened on Hackett Street in the Auckland suburb of St Mary’s Bay, closing the road to traffic and reigniting frustration over infrastructure repairs that residents say were never properly finished.

The hole appeared on the evening of July 23, in a dip in the road that was badly damaged during the January 2023 Auckland Anniversary floods. The site had been covered with a steel plate in the years since, but that patch has now given way.

The opening measures roughly five metres long, three metres wide and more than a metre deep in places, with water visibly running through it beneath the street.

Some residents lost water supply for several hours on the night the hole formed, though services were restored by evening. The closure has forced locals to detour via Shelly Beach Road while contractors assess the damage.

One long-time St Mary’s Bay resident, who has lived in the area for more than 50 years, said the underlying pipework dates back well over a century and that further deterioration could threaten nearby properties. He said the real test would come with the next heavy rainfall, when nobody could be sure how the ground beneath the street would hold.

Contractors were on site through Monday working on repairs, and Watercare has been approached for comment.

St Mary’s Bay is no stranger to this kind of ground failure. A sinkhole opened a few streets away on College Hill in July 2023, snarling central Auckland traffic for months during repairs, and another appeared on the corner of Dunedin and New streets in January 2025, exposing old brickwork beneath the road before it was filled in.

Engineers and council officials have repeatedly pointed to a combination of ageing clay pipes and increasingly heavy rain events as the underlying cause across the older inner suburbs.

The pattern raises familiar questions about the pace of infrastructure renewal in parts of Auckland still carrying visible scars from the 2023 floods. Temporary fixes such as steel plates buy time, but as Hackett Street shows, they don’t always buy enough.

Residents in the area will be watching closely to see whether this repair holds through winter, or whether St Mary’s Bay finds itself back in the headlines the next time the rain sets in.