Wellington Scoop

2004 report on problems with Dixon Street sewage tunnel was archived and forgotten

Wellington Water has responded to an independent review published on Thursday that says a 2004 report identifying problems with the Dixon Street wastewater tunnel was effectively lost.

The NZ Herald reports that the review reveals the Wellington City Council commissioned a person-entry inspection of the tunnel in 2004. It identified an area of significant corrosion deterioration in the same place where the tunnel failed last December. The report recommended a further inspection on a 10-year cycle following repair work. A hard copy of the report was archived in a project file, but was misplaced when responsibility for water management changed hands to a company called Capacity and then again in 2014 with the establishment of Wellington Water.

“Few staff in key wastewater network decision-making roles from the time of that study are still within Wellington Water and that information was effectively lost,” says the review.

The Herald quotes the review as listing management of information as one of the key things that led to the tunnel collapsing and which need to be addressed to help prevent the same thing from happening again.

DomPost: Review blames a litany of failures for the collapse, most notably a lack of regular inspections and consistent underfunding.

News from Wellington Water
Wellington Water has released the results of an independent review that it commissioned into the blockage of a wastewater tunnel beneath Dixon St in December 2019. The purpose of the review was to consider the causes, response and impacts of the incident, and to identify opportunities for improvement.

Chief Executive Colin Crampton says that Wellington Water accepts the findings of the review. “The review characterises Wellington Water’s response to the incident as strong, which we are pleased to see. However, it also reinforces the critical importance of quality asset condition data for minimising risk and informing decision-making.”

Mr Crampton said that this has been a priority for Wellington Water since it was established in 2014. “We inherited a diverse mix of historical asset data from councils around the region, in a range of formats and systems, which we have been working to digitise and consolidate within a single platform, and that work is ongoing. We have also implemented continuous condition assessment programmes to improve the overall quality of the data we hold.

The review highlights that not all the condition information that existed at the time was transferred to Wellington Water on its establishment, which further underlines the importance of systematic asset data management.”

Mr Crampton says that he is delighted that Wellington Water’s shareholder councils are all increasing their investment in condition assessment.

“Our advice to councils as part of their Long Term Plan processes has been that more extensive condition assessment programmes enable better prioritisation of investment in renewals, reducing the risk of incidents like Dixon St.”

Wellington City Councillor Sean Rush, who holds the Three Waters portfolio for the city, says the December incident and the subsequent review underline the importance of this work.

“Wellington City Council has approved $400,000 in funding to accelerate Wellington Water’s asset condition assessment work, meaning the condition of all high-criticality assets in the city’s drinking water and wastewater networks will be assessed within the current financial year.”

The review has been submitted to the Regional Council and the Wellington City Council.

Read the review here.


  1. Hel, 14. July 2020, 20:30

    The DomPost report states Wellington Water weren’t even aware of the wastewater tunnel that failed. If that is the case then there is no way the failure is related to any funding shortfall, as they didn’t know it existed and had never inspected it. Lack of understanding of the network and failure to carry out proper and regular inspections look like the main issues, these are their fundamental responsibilities. This organisation feels like it is lacking the basic skills, knowledge and experience to do their job, not confidence inspiring.

  2. michael, 14. July 2020, 22:43

    Wellingtonians are paying huge costs for the loss of corporate knowledge and expertise in the rush to offload the council’s major responsibilities. WCC should take a good look overseas where, according to the Guardian in 2019, 77% of UK councils were bringing services back in-house to gain flexibility, save money and improve the quality of services. The Mayor of Hackney found that his council has “seen that at almost every step you get a more coordinated response, save money, create better services and improve terms and conditions for the workforce”

  3. groggy, 15. July 2020, 11:04

    Interesting that at the same time that the WCC were refusing to fund pipe repairs and upgrades, they were happy to throw money at pet projects like the runway extension, the convention centre and the Island Bay cycleway. Not to mention the highly paid CEOs and renamings at WREDA. Which have all cost ratepayers many millions at the same time as they wouldn’t find $400k for critical sewage repairs. Just shows how badly we have been served by successive councils

  4. michael, 15. July 2020, 11:11

    Surely, Wellington Water’s perceived lack of understanding of the network is down to the WCC. It was the council’s responsibility to ensure WW was fully briefed and had access to all reports when they took over management. Not only that, in 2017 WW warned WCC that the level of under-funding was not sustainable. Ultimately the buck stops with the WCC, as Wellington’s infrastructure is one of their main responsibilities, regardless of who they get to manage it.

  5. Morris Oxford, 15. July 2020, 17:48

    michael, why should highly-paid councillors be bothered about mundane things like water. The responsibility has been hived off into the distance and must take second place to vanities on the waterfront. These can be such fun!

  6. michael, 15. July 2020, 23:45

    Spot on Morris . . . and by the sounds of their plans for the library we will be putting up with a lot more burst pipes in the future as well.