Why infrastructure debt is dragging us down — and who ends up paying for it

Somewhere in your council's area, there is a water main that was laid in the 1960s. It has exceeded its design life. It will leak, or burst, or quietly contaminate supply at some point in the not-too-distant future. The council knows it's there. Replacing it is expensive. So is not replacing it.

That pipe — and hundreds of thousands like it across the country — is the physical form of New Zealand's infrastructure debt. It is not a metaphor. It is a real object with a real cost attached to it, and the question is not whether that cost will be paid, but when and by whom.

How a $200 billion deficit accumulates quietly

Infrastructure debt doesn't announce itself. It builds up in the gap between what councils spend on maintenance and renewals, and what they'd need to spend to keep their assets in good working order.

Local Government New Zealand and Infrastructure New Zealand estimate that gap has grown to at least $200 billion nationally. That figure represents the cost of work that has been deferred — often for years, sometimes for decades — across water, wastewater, stormwater, roads, and community facilities.

The structural cause goes back further than most people realise. New Zealand councils were not legally required to fund depreciation — to set aside money to replace ageing assets — until 1996. Before that rule change, there was no formal obligation to account for the future cost of replacing what was being used up. Rates were kept low. Infrastructure wore out. The obligation to replace it accumulated invisibly.

Pipes and roads: a coincidence of timing

Much of New Zealand's core infrastructure was built within a compressed period — post-war, through the 1950s, 60s, and into the 70s. Water mains, wastewater pipes, roads, bridges. Most of it was designed to last 50 to 80 years.

Fifty years after 1970 is 2020. Eighty years after 1960 is 2040. The country is now in the middle of the window when a significant proportion of that infrastructure reaches end of life — not gradually, across a century, but clustered, because it was all built at roughly the same time.

That concentration of demand is part of why current long-term plans look so expensive. It's not entirely that councils have suddenly become bad at their jobs. It's that the replacement cycle for an entire generation of infrastructure is landing at once.

A pipe that costs $1 to fix today will cost $4 to $6 to fix once it fails. Deferred maintenance is never free — it is always just deferred payment, with interest.

Water infrastructure and the Three Waters saga

Water — drinking water, wastewater, and stormwater — is where the infrastructure deficit is most acute. Councils spend around 36% of their capital expenditure on water. Much of that spending is catch-up: replacing infrastructure that should have been replaced already.

The previous government's Three Waters reform attempted to solve the problem by taking water infrastructure off council books entirely. Water services would be consolidated into a small number of large national entities with the scale to borrow and invest more efficiently than individual councils.

Councils and communities resisted. The reforms were scrapped by the incoming government in 2023, replaced by Local Water Done Well — a model that keeps water ownership with councils but encourages them to set up separate financing structures. As of 2026, 38 of the 68 councils responsible for water services have opted to transfer to new council-controlled organisations. The rest are retaining direct ownership.

The governance debate is now largely settled. The infrastructure problem it was meant to solve is not. Whether water services are run by a council unit or a separate entity, the pipes are the same age. The replacement cost is the same. The ratepayer is still the ultimate funder.

The renewals gap — still there, just narrowing

One way to measure whether councils are keeping up with their infrastructure is to compare renewals expenditure to depreciation. Depreciation is an estimate of how much of an asset is "used up" in a given year. If renewals spending equals depreciation, councils are replacing assets at roughly the same rate they wear out.

For most of the past decade, councils have been spending well below that threshold. The Auditor-General found that in 2024, maintenance spending was only meeting 84% of annual depreciation across the sector.

The 2024-34 long-term plans project an improvement — renewals expenditure is forecast to average around 85% of depreciation over the decade. Better than before, but still a gap. Councils are still not planning to fully replace infrastructure at the rate it degrades.

The reason is straightforward: fully funding renewals, on top of addressing the existing backlog, would require rates increases that councils — and ratepayers — aren't willing to absorb all at once. So the plan is to close the gap gradually, over many years, while carrying the backlog forward.

Rate caps and the risk of making it worse

The government has proposed capping general rates increases at 2–4% per year from 2027. The political logic is clear — rates have risen 35% cumulatively in three years, and that's genuinely difficult for households.

The infrastructure logic is concerning. S&P Global Ratings, which rates 24 New Zealand councils, found that 18 of them projected rates increases above 4% in every year from 2025 to 2029. Not a single one of the 78 councils managed a sub-4% increase in 2024/25.

If councils cannot raise enough revenue through rates, the options narrow: cut services, borrow more, or defer maintenance again. Two of those three options push the infrastructure problem further into the future — exactly how the current $200 billion backlog accumulated.

S&P warned that the caps could "drive interest expenses higher, meaning a larger proportion of rates will go directly toward servicing borrowings" — and that this path "would limit councils' future debt headroom," reducing their ability to respond to natural disasters or emergencies.

The intergenerational problem at the heart of it

Infrastructure debt is fundamentally a question of intergenerational equity. The communities that built water systems in the 1960s received decades of service from assets they didn't fully fund the replacement of. Today's ratepayers are being asked to fund both current services and the cost of replacing those earlier assets.

There's no clean answer to that. You can't send a rates bill to 1975. What you can do is be honest about the scale of the liability, fund it as steadily as possible, and avoid decisions — like sustained underinvestment — that pass an even larger bill to the next generation.

The current long-term plans represent, on the whole, a genuine attempt to start addressing the backlog. They're expensive because the problem is expensive. The question for ratepayers isn't really whether to pay — it's whether to pay now, or pay more later.