New national report reveals key pressure points across New Zealand's water networks
New Zealand's first complete national picture of public drinking water and wastewater network performance shows many water networks are under pressure, and better data, maintenance and targeted investment is urgently needed.
New Zealand's first complete national picture of public drinking water and wastewater network environmental performance shows many water networks are under severe pressure, with wastewater overflows, drinking water leakage and consent compliance emerging as significant challenges.
Today, the Water Services Authority – Taumata Arowai published the Network Environmental Performance Report 2024/25 (NEPR). This is the third year the Authority has published this report, and the first based off a complete set of wastewater information.
Authority Head of Systems, Strategy and Performance, Dr Sara McFall says the report provides a crucial evidence base as the water sector enters a period of significant change.
"As new water organisations are established, improved financing tools and greater standardisation create opportunities to strengthen network performance over time.
“The Authority has an oversight role, providing an independent view of how the system is performing, where risks are emerging, and where action is needed. This enables the public to see how their water services are performing, and track improvements over time.
"The report shows that many networks are under immense pressure and better data, maintenance and targeted investment are needed to reduce risks to public health and the environment and increase long-term system resilience.
"Good information is critical. Better monitoring, inspection and data quality practices will help operators make smarter decisions and achieve better outcomes for communities,” says Dr McFall.
The report identifies several significant challenges across drinking water and wastewater networks.
Wastewater performance is a particular concern. Operators reported 11,535 wastewater overflows in 2024/25, an average of around 31 a day. Wastewater overflows discharge untreated wastewater to land or water, negatively impacting public health, recreation, food gathering and the environment.
"Capacity constraints, periods of torrential rain, poor asset condition and blockages are severely impacting the effectiveness of wastewater networks in many parts of the country," says Dr McFall.
"Blockages remain a major and preventable cause of wastewater overflows. These are caused by fats, oils, wet wipes and other unsuitable items entering wastewater systems - and New Zealanders need to understand they play a critical role in preventing blockages.
"We recommend that operators prioritise routine and preventative maintenance to reduce wastewater overflow risks before problems occur and target investment to the areas of greatest need,” says Dr McFall.
The report also highlights challenges in wastewater consenting and compliance.
Dr McFall says that close to half of existing wastewater consents will require renewal within the next 10 years.
“We are aware of considerable non-compliance with wastewater consent conditions but expect improvements through the new national wastewater environmental performance standards, which we published in late 2025, providing a clear and consistent framework for councils renewing wastewater consents. The new national standards also require consistent monitoring and public reporting for discharges and overflows improving visibility and the ability to effectively enforce non-compliance.
The report shows drinking water network performance is uneven across the country.
Loss of treated water remains a significant wastage issue, with around one-third of councils reporting at least one drinking water network with very high leakage levels by international standards.
Freshwater sources of the nation’s drinking water are also under pressure where water consumption is high or consent limits are exceeded.
Areas where most homes have water meters tend to use less water than the national average. This suggests metering can help reduce water use and loss. However, water meters are not used consistently across New Zealand. There are about 980,000 residential water meters nationwide. Nineteen councils and Crown-owned operators have meters on at least 90% of homes.
For drinking water networks, Dr McFall says reducing water loss and improving their network understanding must remain priorities.
"Operators should continue to reduce leakage, improve metering and pressure management where appropriate, and plan for future water availability, network renewal and growing demand.
“The Authority is leading a range of initiatives to help improve water services including implementation of wastewater environmental performance standards, development of National Engineering Design Standards for more consistent water infrastructure design, simpler consenting pathways for smaller wastewater treatment plants, and support for water meters through benchmarking information.
"As New Zealand's water sector evolves, insights from the NEPR can help support more resilient networks, better environmental outcomes and more reliable water services for the future."
More information