31 raw sewage overflows a day is now a boardroom liability

The number that should worry every board

New Zealand’s water network discharged untreated wastewater into the environment 11,535 times in 2024/25, an average of 31 overflows every single day. The Water Services Authority’s third annual Network Environmental Performance Report, released on 28 July 2026, also found that about 15% of assessed drinking and wastewater pipes are in poor or very poor condition.

But the line that matters most for anyone pricing risk came from Sara McFall, the Authority’s Head of Systems, Strategy and Performance, who told Mike Hosking that “in many cases, the condition of infrastructure is unknown.” You cannot fix, insure, or plan around an asset base you have not measured.

The first honest look at the whole network

This is the first report to draw a complete national picture, covering 559 public drinking water networks with 687 treatment plants and 56,000km of pipe, plus 331 wastewater networks running 35,000km of pipe and serving 84% of the population. The stormwater and wastewater assets alone are worth more than $20 billion.

Run that infrastructure honestly and you get an uncomfortable finding: 22% of treatment plants are operating on expired resource consents, meaning they are likely not designed or run to current good-practice standards. Nearly half, 48%, are up for consent renewal within a decade, and operators take an average of 5.5 years to renew once a consent lapses. That arithmetic produces a deepening backlog, not a shrinking one.

Leaks you are already paying for

Monitoring is thin. The report recommends 30% of networks be inspected by CCTV every five years; only 10% currently are. Around 32% of councils have at least one network rated ‘very inefficient’ for leakage, and average household drinking water use has crept to 627 litres a day per connection, up from 604, a rise that partly reflects water leaking out of the pipes rather than being used. The Defence Force’s own network is a standout, with 56% in poor condition.

What failure actually costs

These are not abstractions. In February 2026, Wellington’s Moa Point plant failed catastrophically, at one point discharging roughly 70 million litres of untreated sewage to sea a day. The southern coast closed and local businesses lost thousands of dollars to access restrictions.

In Auckland, a sewage overflow into the Mahurangi River wrecked oyster farmers’ livelihoods and cost Watercare $2 million in compensation. In Christchurch, the council’s plan to pump partially treated sewage to sea drew a public rebuke from Fisheries Minister Shane Jones in March 2026, who called for proper engineering rather than a workaround.

With about 74% of wastewater discharged to coastal environments, the exposure lands squarely on aquaculture operators, coastal tourism and hospitality, and exporters whose brands trade on clean-water claims. Developers face uncertain capacity and rising contribution levies. Insurers face a claims tail that just got harder to price, because a meaningful share of the network’s condition is genuinely unknown.

The people problem behind the pipe problem

Even with money, the capacity to fix this is thin. In February 2026, Engineering New Zealand chief executive Dr Richard Templer noted “more than 2,000 roles lost across 60 engineering firms” over the past year, with construction sector employment down 12,000. He welcomed the National Infrastructure Plan’s pivot “from ribbon cutting to renewal” but warned that “the instability of the policy roundabout has real consequences”, with delays raising costs and risking quality.

The cost question nobody answers

Three Waters, Affordable Water, repeal, now Taumata Arowai as regulator with assets back in council hands. Every iteration of reform has dodged the same question: who pays, when councils are rate-capped by political reality and development contributions are contested. McFall did point to one genuine positive, noting it is “good to see the increased use of water meters, which lower water use and identify leaks”. Better data is the precondition for a fix.

But the report itself is the verdict. New Zealand has run a $20 billion-plus asset base on expired consents and unmeasured pipe for decades. The next Moa Point is not a possibility to insure against; it is a question of which region draws the short straw and whether your operation is downstream of it.

Sources

• ‘Pretty concerning picture’: New water infrastructure report shows a ‘system under pressure’ (2026-07-28)
• First complete water network report points to ‘severe’ pressures
• Moa Point inquiry must seize opportunity to improve wastewater nationally (2026-03-06)
• Fisheries Minister Shane Jones blasts Christchurch City Council’s ocean sewage plan (2026-03-06)
• Wellington business losing thousands after sewage leak restrictions
• Good Signs In Infrastructure Plan (2026-02)
• NZ water systems particularly vulnerable to climate change