Fixing the pipes – and spending $2.7 billion

Shortly after being elected Mayor, just before Christmas 2019, I received a call telling me a major wastewater pipe had broken on Dixon Street. I promptly headed to the site to meet Wellington Water management and contractors. It was the first of several well reported pipe failures in rapid succession. Some were old pipes, some like the Mount Albert sludge tunnel were only 25 years old.

The state of our city’s pipes had not really been an issue until then, not in the media, not in submissions, not raised by Wellington Water to the Council governance table. Indeed the Council had never said ‘no’ to any request for water related funding.

There was always investment in maintaining and renewing pipes. However, like most of the country the renewals investment was below the depreciation level. That meant that in theory they were ageing faster than they were being replaced.

There was however very significant investment in other parts of the system. We built sewage treatment plants at Karori and the city’s main plant at Moa Point. Until then our city’s sewage was discharged directly off the beach, every day, and successive Councils had failed to address it.

We fixed it.

There was also significant investment in a pollution elimination strategy (upgrading pipes) to cut discharges into our harbour and streams. There was a long term investment in resilient water reservoirs to ensure we have access to clean drinking water if an earthquake cut supplies from our water sources in the Hutt Valley.

Chief Executives are now required by law to write a publicly available pre-election report. The state of our pipes was not even mentioned in Kevin Lavery’s 2019 report. What it did focus on was resilience and access to water in event of an earthquake. It also talked about localized stormwater improvements especially in Tawa around the Porirua stream and tributaries. Less than six months later, the pipes started breaking.

Rapid response to pipe failures

My response, fully supported by the Council, was immediate. In the 2020/1 budget we invested in roving crews and in condition assessment, focusing first on very high and high criticality assets.

It is important that we don’t just dig up and replace pipes just because of their age. Some older pipes have decades of life in them, others fail prematurely. Condition assessment also gives us a better handle on what the expected lifespan of any given type of pipe is in any given ground conditions, and therefore what the depreciation rate on it should be, and the amount of investment we should make in replacements. Interestingly information to date suggests those most critical assets are in better condition than we might have expected.

Mayoral Taskforce

The Mayoral Taskforce on 3 Waters was established in March 2020, reporting back to the Council that December. I chaired the Taskforce and it included Councillors Rush and Condie, Wellington Water, independent experts, mana whenua, and very well informed community members.

We made 48 recommendations. Key recommendations included condition assessment, funding, metering, community involvement, vesting the assets in Wellington Water or an entity that came out of Government water reform which was emerging at the time.

Importantly the recommendations also include being governed in accordance with a statement of intent determined by shareholding Councils, and enabling direct democratic input. That local responsiveness is something not provided for adequately in Government’s three waters reform model, which I don’t support as it currently stands.

My 2021-31 Long Term Plan increased investment in the Council’s 3 Waters to record levels. The 2015-25 LTP planned on investing $1.6 billion over 10 years (inflation adjusted), the 2018-28 LTP raised that to $1.85 billion, and my 2021 LTP to $2.7 billion with sludge being separately funded. I am in no doubt there will need to be further increases in investment.

Great delivery and hard mahi

On the ground – the Willis Street – Dixon Street adit was fixed. Contractors worked long hours over Christmas, and often had to be driven home to ensure they made it safely. Thank you all so much! We brought in specialists from the UK and Germany during lockdown to help fix the Mount Albert tunnel. Part of the main interceptor was relined near Moa Point. A major stormwater pipe under Jervois Quay was fixed, a superb piece of preparation. Instead of a project taking weeks, working off peak only, constantly opening and closing the road, the team carefully planned the operation, did a great job with traffic management, fully closed the road, and finished the job over Queen’s Birthday weekend, even completing it many hours ahead of schedule. That’s also a potential model for the upcoming transformational programme of infrastructure and transport investments.

Reservoir, Sludge Treatment and Landfill

In June 2020. my Council approved the Omaroro Reservoir, a project that had been around for 20 years, and you can now see it nearing completion if you look up Taranaki Street. At 35 million litres it is the biggest single reservoir our city has ever built and doubles the supply of water to the CBD and lower lying suburbs, crucial in the event of an earthquake. It will be operational in November, with landscaping and earthworks completed next year.

We’ve also made big decisions on Sludge Treatment. Sludge is the nasty stuff left over after treatment at Moa Point. Currently it is pumped to the Southern landfill through the Mount Albert tunnel mentioned above, and then partially dewatered and mixed 1 part sludge to 4 parts rubbish. That mixing is to make sure the landfill remains stable. The tunnel’s failure was what required those ‘poo trucks’ to transport the sludge for a while in 2020.

The fatal problem with the 1 part to 4 is that it means we cannot reduce rubbish levels until we fix the sludge. We are at about 1 to 4 now, with 15,000 tonnes of sludge a year, and not dealing with sludge differently would mean keeping filling our landfill far too quickly.

Following extensive options analysis, we have settled on a Lysis Digestion – Thermal Drying plant, to be located beside the Moa Point plant. The sludge plant will reduce the sludge to small dry pellets. All this also means we have also been able to agree on a much reduced landfill extension, and will be able to drive waste minimization. Both sludge treatment and landfill extensions need to be in place by 2026 when the existing landfill reaches capacity and its consent expires. We are currently seeking consent for the sludge plant, with the landfill consent to be lodged pre-Christmas.


Following the Willis Street pipe failure, I tasked Wellington Water with developing a plan to prevent further wastewater overflows into the harbour should any further pipe breaks occur. I announced that plan last year, and Wellington Water are well and truly getting on with delivering it.

The diagram shows the Interceptor. Think of that as the main highway transporting wastewater to Moa Point. Side roads – pipes – join it. Central City wastewater is collected and is pumped up through ‘rising mains’ (big pipes) to join the interceptor. The orange and green mains on the map are existing rising mains. The blue and purple mains do not yet exist. Problem is that if the existing rising mains fail, the wastewater cannot get to the interceptor. There is a certain amount of storage in the system but if that is filled and an overflow pipe is not able to be joined up in time, wastewater ultimately ends up going into the harbour as happened at Christmas 2019.

The plan is to build alternative pathways. One has already been completed up Whitmore and Bowen Street in the north of the central city. The blue pipe up Taranaki Street and the associated pump station are now well underway, a $24 million investment, to be completed around the end of next year. The purple pipe will follow, and the old orange and green pipes will need replacement.

I have told Wellington Water that the pipes outside Takina and the Library need to be completed before the buildings open/reopen, and that is being done. When completed we will then have a resilient downtown wastewater network, keeping our harbour clean. Importantly it will also provide for population growth in the area.

ww renewals

Water Pipes

There is no question that there are more water pipe leaks across the city and across the region. This is from both public (council owned) and private pipes. There is an issue with age, but as the graph shows there has been a dramatic turnaround in water use per capita following the Kaikoura earthquake. Water use per capita was reducing steadily over many years until Kaikoura, and since then it has started to rise, from slightly under 350 litres per person per day to 380 plus. That is significant.

It is inconceivable that the earthquake that has caused a significant number of buildings to be demolished, would not have also caused damage underground.


graph water demand


Wellington Water has a significant backlog of jobs across the region which it is working to resolve. Much of the water lost is lost into the ground rather than being visible, so there has been investment in more fine-grained metering to better locate leaks, along with other acoustic and non-acoustic techniques.

Wellington Water is also investing in training more staff to get the jobs done, with a first intake some 17 earlier this year and a further intake planned shortly. A proposal for a training programme was proposed to and declined by the Government as part of its Covid Response and Recovery and New Zealand Upgrade packages in 2020. I am advised that approximately 50 people would have been graduating from that programme about now had it been funded.

One frustration I hear from time to time is about how long it can take to fix a leak.

Sometimes it is a prioritization issue, sometimes it may be that there are other services (power, gas etc) that need to be worked around, but regardless I have said to Wellington Water that there needs to be more consistency in providing feedback to members of the public who alert WWL to leaks about progress and how long a job will take (and why). Radio silence is not helpful. The WWL website now includes useful information on the status of all the many hundreds of jobs across the region, and a text service to keep in touch. I expect further improvements will be made.

Having just recently joined the Wellington Water Committee, I have also asked for a clear timetable to deliver a comprehensive asset management plan. That AMP will also include ensuring we have a clear picture of growth-related infrastructure costs related to our key targeted growth areas, Tawa (railway line), Johnsonville (mall redevelopment), Central City and Mass Transit corridor.

We have a live proposal for support for infrastructure upgrades to the Government’s Infrastructure Acceleration Fund, to support housing intensification and commercial re-development in the heart of Johnsonville.