Taumata Arowai has released its third annual report on water networks, the first to include robust wastewater statistics from all 71 managed network operators servicing 84% of New Zealand's population. RNZ

The report covers 559 public drinking water networks with 687 treatment plants and 56,000km of piping, alongside 331 public wastewater networks with 318 treatment plants and 35,000km of pipes.

About 15 percent of pipes were in poor or very poor condition. That figure is likely an underestimate, according to the report.

The data showed 11,535 wastewater overflows in 2024/25, an average of 31 per day. Average water use across New Zealand was an estimated 678 litres per connection per day. About a third of councils had at least one drinking water network with "very high" leakage levels by international standards.

On the wastewater side, 22 percent of treatment plants were operating on expired consents. Nearly half, 48 percent, were up for consent renewal within the next 10 years. Operators took an average of five and a half years to get consents back up to date.

About 74 percent of wastewater was discharged to coastal environments. In metropolitan areas, 99.6 percent of wastewater was treated to tertiary quality using advanced processes including filtration, nutrient renewal and ultraviolet disinfection. Metropolitan areas had nearly three times as many blockages per 100 metres of pipe compared to provincial and rural areas.

Taumata Arowai was established by the then-Labour government in 2020 as part of its water reforms, following the Havelock North campylobacter outbreak. Water services were previously regulated by the Ministry of Health. The National-led government retained Taumata Arowai. Dr Sara McFall, Taumata Arowai's head of systems, strategy and performance, is associated with the report's release.

The broader regulatory context matters here. Taumata Arowai's Statement of Performance Expectations 2025/26, published in July 2025, notes that pressure problems in pipes can cause contaminated water or other liquids to be drawn into the drinking water network from user connections. The authority's Network Environmental Performance Report 2023/24 found that some operators report very high pressure that can lead to more bursts, especially in older infrastructure. Its Early Insights 2024/25 document, published in April 2026, states that some drinking water networks are operating under reference pressure.

These pressure and leakage findings take on a sharper edge against the pipe-condition data in the new report. If 15 percent of the network stock is already in poor or very poor condition, and that is a floor rather than a ceiling, then the consent-renewal backlog compounds the problem. Operators facing a five-and-a-half-year average turnaround to renew consents, with 48 percent of plants due within a decade, are working against deteriorating assets. The 22 percent already on expired consents are operating in a regulatory grey zone in the interim.

The metropolitan-provincial divide is worth noting. Tertiary treatment coverage at 99.6 percent in metropolitan areas is a strong baseline, but metropolitan networks also carry nearly three times the blockage rate per 100 metres of pipe. Higher density, older reticulation and higher connection counts all bear on that figure. The report does not disaggregate blockage causes, but the infrastructure age profile and pressure data from prior Taumata Arowai publications are consistent with what the new pipe-condition numbers show.

Taumata Arowai has been building toward this dataset across three reporting cycles. Its Environmental Performance Performance Measures Record Keeping Requirements for Drinking Water Network Operators Notice 2023, now archived, set the data-collection framework. The authority published updated drinking water rules and standards in August 2025 that include Drinking Water Network Environmental Performance Measures for council-operated networks. The Network Level Data spreadsheet tracks metric RE1, estimated total drinking water network water loss in cubic metres per year. A Statement of Intent 2022–2026 covers environmental performance measures and source water risk management guidance.

For those working in local government water management, the report crystallises what has been an emerging picture across Taumata Arowai's publications. The authority now has a national dataset covering the bulk of the population, and the numbers on overflows, pipe condition, leakage and consent status provide a baseline against which future annual reports will be measured. The political significance is that this dataset exists at all. The water reforms that created Taumata Arowai were contested, and the National-led government's decision to retain the regulator while scrapping the Three Waters model means the monitoring function continues under a different delivery structure. The data collection obligations on network operators remain.

What the report does not yet provide is trend data. As the third annual report and the first with comprehensive wastewater coverage, it establishes a starting point. Year-on-year comparisons on pipe condition, overflow frequency and consent compliance will become possible in subsequent reporting cycles. For now, the figures stand as a snapshot of a system under measurable stress.