National Engineering Design Standards

Currently, councils and water service providers use locally developed codes of practice to set out the requirements for the design and construction of water supply, wastewater and stormwater infrastructure. There are approximately 45 codes in use across New Zealand. As a result, water infrastructure is designed and built under a range of local standards, leading to inefficiencies and inconsistencies. 

The National Engineering Design Standards (NEDS) are intended to improve consistency by setting out nationally consistent, mandatory, performance-based standards that will apply to all networks operated by water service providers. 

The national standards will be supported by codes of practice that provide detailed technical specifications which set out how the standards could be met. If a code of practice is followed, then the infrastructure is deemed to comply with the relevant standard.  

The approach to the NEDS set out under the Water Services Act 2021 (the Act) is new. While many international jurisdictions maintain nationally consistent design codes, the mandatory performance-based standards are unique for three waters infrastructure. 

The approach is comparable to the performance-based system used under the Building Act. All building work in New Zealand must meet the performance criteria set out in the Building Code. The Code states how a building must perform its intended use rather than describing how the building must be designed and built.

The Building Code has three main compliance pathways, including acceptable solutions. These are comparable to the codes of practice which will provide a pathway for meeting the NEDS.

We are looking for feedback on the proposed framework for the NEDS and codes of practice. As a new approach for water services, we want to make sure that the framework is useable and fit for purpose. We are also seeking feedback on our approach to prioritising what is covered in the first tranche of the NEDS. 

At this early stage, we need to develop an organisational framework for the NEDS that is fit for purpose. This framework will then guide how we develop the technical content of the standards and codes of practice. Following this initial sector engagement, we will use the sector’s feedback to help us identify the areas to prioritise for the first tranche of standards and codes. 

Over the coming months, we will develop the technical detail, using existing information where it is available and meets our needs. We expect to undertake public consultation on the full detail of the NEDS and codes of practice in mid-2027.  

Under the Act, the NEDS and codes of practice cover water supply, wastewater and stormwater infrastructure operated by water service providers (including councils and water organisations). This means the NEDS capture the piped network and horizontal infrastructure within the network, such as pump stations, as well as treatment plants. 

The NEDS will also capture any infrastructure that becomes part of a water service provider’s network in the future. This means that developments that connect to the public network will need to meet the mandatory standards. 

We have made the decision to exclude drinking water and wastewater treatment plants for the first tranche of the NEDS. This decision recognises that we have other tools that may be more appropriate to address challenges, such as wastewater environmental performance standards, drinking water standards and, in time, infrastructure design solutions.

The Act sets out a requirement for the NEDS to cover the full lifecycle of three waters infrastructure. This includes design, construction, repair, renewal, replacement, operation, maintenance and decommissioning of the infrastructure. This is a change from current practice, where local codes of practice predominantly focus on design and construction. This change recognises the importance of considering the whole life of an asset and ensuring that asset has been designed and installed in a way that enables optimum operation and maintenance. 

We intend to cover all three waters within the first tranche of the NEDS. This ensures a cohesive framework that provides certainty to those who design, install and operate the infrastructure.  

Under the Act, the purpose of the NEDS is providing for national consistency in the design, construction and operational performance of water services networks, including by:

• promoting the efficient and financially sustainable operation of those networks 
• improving the networks’ reliability and resilience 
• protecting public health and safety 
• contributing to the continuous improvement of water services. 

The NEDS are expected to provide consistent standards that lift the performance of our three waters networks while supporting efficient investment. This could include reducing the water lost from our drinking water pipes, supporting water service providers to better manage wastewater overflows and providing a consistent approach to designing for extreme weather events.  

We are aware of work done under the previous government to develop nationally consistent codes.  These codes were referred to as National Engineering Design Standards; however, they were more similar to codes of practice under the current NEDS framework. Significant work was undertaken by experts across the water services sector to develop these codes using best practice from existing local codes.

We will use this previously completed work to inform development of the new NEDS. This information provides a useful starting point. However, the previous codes covered a narrower scope and are more like codes of practice as they were not designed to be used as mandatory performance-based standards.  

We expect to publish the first NEDS and associated codes of practice in 2028. This timeframe recognises that we need to work with the sector to ensure the first tranche is cohesive and fit for purpose. The NEDS and codes of practice will be set out in secondary legislation, and will require approval from Cabinet. 

We expect to publicly consult on the draft NEDS and codes of practice in mid-2027. We will work with technical experts from across the sector to develop the content of the NEDS and codes of practice. 

We will develop an implementation approach that ensures the introduction of the NEDS is phased in a way that considers the compliance burden on water service providers. We will test this approach with the sector during public consultation in 2027. 

The Act provides a pathway for alternative solutions. Water service providers can approve an alternative approach to the codes of practice if they can satisfy themselves that the alternative will still enable the NEDS to be met. 

The intent is to develop national codes of practice that replace the need for local codes. We recognise, however, that there will always be situations that require a different approach due to unique site-specific factors.   

Yes. The NEDS will capture both new and existing infrastructure. The implementation approach will consider when the NEDS should apply to existing infrastructure. For example, we may decide that the NEDS only apply above a certain scale of renewal project.  

Water service providers must ensure that any alternative solutions they approve will comply with the standards. We must be provided with a copy of alternative solutions and may issue guidance on how an alternative should be assessed. We will not review or approve alternative solutions.  

Our intention is to work closely with the sector. The NEDS and codes of practice are a new tool that will be a significant shift for the sector. There are many benefits that could be achieved with the new approach. However, it will be important that the technical detail is accurate to realise those benefits. 

We have begun engaging with sector groups such as Āpōpō and Water New Zealand. We are also establishing a technical reference group to allow for early testing of material as it is developed. Development of the technical detail will be supported by subject matter experts for the key areas of focus. If you would like to register interest in being involved in the technical workstreams, please email us at neds@taumataarowai.govt.nz.  

We believe that asset data standards will be an important part of achieving greater national consistency. Water New Zealand and its members have invested time and expertise into the development of the existing asset data standards.  We will explore opportunities for incorporating this work into the NEDS. 

A list of priority areas for the development of technical detail will be confirmed following this initial engagement.