For the stormwater sector

Stormwater is the water that runs off impervious (water resistant) surfaces such as roofs, roads, driveways and footpaths. In urban areas, runoff goes down drains into stormwater pipes or channels, or into green infrastructure and is carried to rivers, lakes or the sea.

We oversee the management, regulation and performance of stormwater networks in urban areas. Our role includes developing national standards and monitoring and reporting on environmental performance. Recent changes to the Water Services Act 2021 give us more ways to improve the performance and delivery of stormwater infrastructure. Our work on stormwater has just begun and our functions will be rolled out over time.  

A range of other agencies are involved in stormwater management, including:

•        regional councils, which are the primary regulators for managing stormwater, through granting, monitoring and enforcing resource consents
•        the New Zealand Transport Agency – Waka Kotahi, responsible for drainage from the state highway network  
•        Earth Sciences New Zealand (formerly NIWA and GNS Science), which undertakes research to help assess and manage the effects of stormwater and urban development on streams, estuaries and harbours
•        KiwiRail, which manages stormwater assets within the national railway corridor
•        local authorities, which regulate stormwater management on private properties through provisions in the Building Act 2004 and associated instruments.

Current and future work programmes

We can do a range of things to support improvements in infrastructure and the environmental performance of stormwater networks.

• Develop national standards such as the Stormwater Environmental Performance Standards, National Engineering Design Standards and Infrastructure Design Solutions following a consultation process.
• Set Network Environmental Performance Measures so operators must monitor and report on the performance of their services networks to better understand and manage environmental and public health risks.  Currently there are no measures for stormwater in place.
• Contribute to the development of Stormwater Network Risk Management Plans by water service providers, to be adopted within three years of the Local Government (Water Services) Act’s enactment. These plans must align with any relevant stormwater standards or targets and must be reviewed at least every 10 years. 
• Develop environmental performance targets in future, to further support improvements, once sufficient performance data becomes available.