FAQs for NEPR 2024/25
What does the report tell us about water leaks?
Water loss (leaks) from drinking water networks is a significant issue.
- Leaks create a risk of illness: International studies estimate that up to 30% of outbreaks of waterborne diseases are associated with issues in drinking water networks (e.g. from leaking pipes, breaks in mains or low water pressure).
- Leaks impact the environment: Leaks result in more water than is necessary being taken from the environment to ensure communities have enough water to drink.
- Leaks cost communities: Water loss means additional cost for communities is required to treat additional water to make up for losses through leaks.
Concerningly, more than 32% of network operators that provided reporting had at least one network with the worst available rating for water loss according to an international index – indicating an inefficient network with poor maintenance and asset condition.
Water loss data quality varied significantly across network operators. Good data on water loss is essential for drinking water network operators to feel assured that they have sufficient and safe water available to meet demand and are not taking more water than is needed from the environment.
The Authority continues to investigate the most effective way to collate and report data on water loss to give the public transparent information about the performance of their networks.
What does the report tell us about wastewater networks?
Wastewater networks are under pressure. An example provided by the extent of overflows – where untreated wastewater is discharged to land or water creating risks for public health, recreation, food gathering and the environment. Operators reported 11,535 wastewater overflows in the past year, around 31 each day. These are commonly linked to capacity constraints, blockages, wet weather, infiltration and ingress, and poor asset condition.
In addition, wastewater asset condition is poorly understood. While only 17% of metropolitan wastewater pipe length is reported to be in poor or very poor condition, this is likely to be an underestimate, because CCTV inspection levels are well below best practice levels.
Wastewater consenting and compliance are weak points. About half of wastewater treatment plants will need a new resource consent within 10 years, and some are already operating on expired consents. Non-compliance with consent conditions appears widespread. New national wastewater environmental performance standards will bring certainty and consistency to the sector and set limits on the timeframes for re-consenting of wastewater treatment plants.
Why is it important for network operators to have a good understanding of their networks?
Good information helps network operators understand risks, plan maintenance and renewals, and target investment where it is most needed. Understanding asset condition helps operators identify where assets may need to be maintained, repaired or replaced.
Without reliable information about asset condition, water loss, overflows and network performance, it becomes harder to prioritise funding, manage environmental and public health risks, and plan for future demand, climate change and growth.
Is the quality of data that informs this report improving?
Yes. The quality and completeness of the data reported to the Authority and used in the NEPR is improving. This year's report provides New Zealand's first complete national picture of public drinking water and wastewater network performance.
All 71 network operators submitted data, and reporting completeness improved significantly across both drinking water and wastewater measures. Drinking water data completeness reached 99% for provincial councils and 96% for rural councils, while all wastewater results were above 90% completeness.
However, there is still work to do to improve the reliability of some information. The report identifies ongoing concerns with areas such as wastewater pipe condition, water loss calculations, wastewater bypass reporting and some asset condition information. In some cases, operators are relying on desktop assessments, historical information or limited physical inspections rather than direct measurement.
Overall, the trend is positive. Better information is helping operators build a more complete understanding of their networks and where improvements are needed.
What are you doing to improve stormwater reporting and oversight?
The Authority's stormwater oversight role is still developing. The 2024/25 NEPR includes information on how stormwater systems operate, the pressures and risks they face, and how they interact with wastewater and drinking water networks.
National stormwater data remains limited because there is not yet a nationally consistent set of stormwater performance measures, and stormwater systems are complex to monitor.
The Authority intends to develop stormwater performance measures, standards and guidance over time. This will support more consistent reporting and provide a more complete view of how drinking water, wastewater and stormwater networks perform together as an integrated system.
What recommendations does the Authority have for network operators?
The Authority recommends network operators:
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prioritise routine and preventative maintenance to reduce wastewater overflow risk before issues arise
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carry out public education campaigns where preventable blockages contribute to poor performance
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target investment to the areas of greatest need, including meeting regulatory requirements such as discharge quality limits under the wastewater standards
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address poor asset condition and the wet weather, capacity, infiltration and ingress issues that increase overflow risk
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continue to reduce water loss, improve metering and pressure management where appropriate, and plan for future water availability, network renewal and growing demand
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strengthen fit-for-purpose monitoring, inspection and data quality practices across drinking water and wastewater networks.
What is the Authority doing to help network operators address the issues highlighted in the report?
The Authority has a significant work programme underway to help improve water services infrastructure across New Zealand. Key areas of focus over the next few years are outlined below.
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Wastewater environmental performance standards. Four initial standards, announced in late 2025, are currently being implemented through new resource consents for treatment plants and networks and will be a step change in how wastewater services are managed and publicly reported. The Authority is also providing guidance to councils to make consenting processes more consistent. Further wastewater standards are being developed.
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Overflows standard. This will improve reporting by requiring wastewater overflows to be reported in a clear and consistent way based on their level of risk.
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National Engineering Design Standards. The development of these will improve consistency in the way new water infrastructure is designed, built, renewed and maintained across the country for drinking water, waste and stormwater networks.
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Infrastructure design solutions. The development of these will make it easier to upgrade smaller wastewater treatment plants by streamlining the consenting process through modular solutions. This work is focused on plants serving communities of 5,000 people or fewer, where consent renewals can be particularly challenging.
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Benchmark information for water meters. This will support the rollout of water meters by water service providers. Water meters can help reduce water loss and encourage more efficient water use.
W-EH12 – Number of times that wastewater overflows were caused by capacity being exceeded in the wastewater network
Since the report was published, Waitaki District Council has provided corrected data for W-EH12 – the number of wastewater overflows caused by capacity being exceeded in the wastewater network.
The original reported value was 194 wet weather overflows. Together with three blockage-related overflows, this equated to 91 overflows per 100 km of wastewater pipe.
The corrected value for capacity-related overflows is 42, which, together with the three blockage-related overflows, equates to 21 overflows per 100 km of wastewater pipe.