Wellington Water warning: 1000 more leaks a year, pipes under airport could collapse

Wellington Water has briefed councillors on different investment options for its ageing infrastructure. Photo / Mark Mitchell

Wellington City Council’s budget for water infrastructure is “insufficient to meet some of the most basic needs for the city”, and there will be 1000 more leaks a year without more money.

The current budget does not include money for upgrades like corroding pipes in the vicinity of Wellington Airport that are at high risk of collapse and could result in sewage spilling out through the airport and Kilbirnie in wet weather.

Wellington Water has briefed councillors on different investment options for the city’s ageing pipes as the council puts together its 10-year budget, known as a Long Term Plan.

The water company warned the current budget is insufficient, and even if the council increased this financial year’s operating budget of $50.5 million to include unavoidable cost increases, it would not cut the mustard in Wellington.

It’s estimated there would be a backlog of 3500 leaks by the end of the financial year, and this number would increase by 1000 leaks a year if the budget stays as it is.

“The number of service failures, sewage overflows, leaks and flooding events will increase,” Wellington Water documents said.

Wellington Water recommended the budget be increased to $66.2m instead.

Meanwhile, the company advised the council would need to double its capital expenditure budget over the next 10 years to almost $1.8 billion to deliver all the projects it possibly could.

This includes wastewater pipes in the vicinity of the airport which are corroding and at a high risk of collapsing.

Sewage could ‘spill out’ through Wellington Airport

The Eastern Trunk Main, on the Miramar side of the airport, is in very poor condition, and raw sewage could spill into the airport’s logistic centre if it collapsed.

“The airport has started redeveloping the logistics centre, and the risk [of] collapse through construction is expected to increase,” Wellington Water documents said.

There is a contingency plan in place to pump sewage around the site, but this would hit the council’s operational spending budget.

Wellington Airport infrastructure general manager Nick Petkov said the pipes were of sufficient depth that their condition does not pose a threat to aircraft operations.

“We conduct regular inspections of all our airfield areas to ensure their integrity and safety for aircraft operations.

“Wellington Water is responsible for managing and maintaining this infrastructure on behalf of Wellington City Council. We are working closely with them to enable any future remedial works that may be required.”

Councillor and Long Term Plan, Finance, and Performance Committee chairwoman Rebecca Matthews said it seemed like the council had agreed to put a lot of extra money towards water in recent years, but has still been told not even basic work could be done.

Wellington Water network strategy and planning general manager Julie Alexander said the council was coming off a low base after not keeping up with renewals across the network in the past.

“You are dealing with a legacy issue, I’m afraid.”

Council officials will use the Wellington Water advice to form their own investment recommendations for councillors to consider next month.

Georgina Campbell is a Wellington-based reporter who has a particular interest in local government, transport, and seismic issues. She joined the Herald in 2019 after working as a broadcast journalist.