Lack of inspection, heavy rain led to Auckland sinkhole, says report

Heavy rain and crumbling century-old block work are among factors being blamed for the collapse of a major sewer line in Auckland, a report has revealed.

The report, released today, listed high rainfall and the deteriorating condition of a small section of sewer as reasons that led to the collapse.

Watercare has been told to improve its inspection practices.

The giant sinkhole resulted in nearly eight million litres of wastewater pouring into Waitematā Harbour every day.

Watercare released its findings, with officials apologising and promising to work on rebuilding its sewer network.

The extreme rainfall events in 2023 were the biggest of seven contributing factors, leading to accelerated erosion, the infiltration of groundwater and the formation of cavities within the pipes.

In a very pointed remark, the report also noted Watercare will spend nearly $2 billion over the next 20 years, but that is less than and later than preferred, due to Auckland Council's debt constraint.

For more on this infrastructure issue facing Auckland, watch the video at the top of this article.