Water recycling across New Zealand: The opportunities are here, the time is right, so what are we waiting for?

New Zealand’s precious water resources are finite, with a growing need for action to conserve and manage our water supply. By learning from international practices in recycled water use, we can develop customised standards for New Zealand’s unique needs to effectively manage our water supply into the future.  

Strengthening water supply resilience

Until recently, there has been a perception by New Zealanders that water resources are inexhaustible, and that the tap will never run dry. As climate change impacts and drought scenarios are better understood and communicated, there has been a rise in both social anxiety regarding water supplies and a drive for water resource protection. Risks to potable water supply quality and quantity are ranked as one of New Zealand’s most urgent climate risks.

Not all consumptive uses of water require potable quality water though, and diversity of water supplies is critical to protect against the uncertainties and extremes of climate change and ensure total catchment resilience in the longer term. With the global drive for more sustainable resource use, there is a growing need for energy-efficient alternatives to seawater desalination and transporting water over long distances, especially as freshwater resources become less reliable.

New Zealand has shown a keen interest in adopting alternative water sources, aligning with international strategic trends. In the 2022 Watercare Citizens’ Assembly project, it was recommended that recycled water be developed as the next source of drinking water for Auckland. Recycled water for irrigation is also being considered in the Marlborough wine region.

Supporting waterway protection

New Zealand is on the precipice of substantive change across the water sector. With the repeal of Three Waters and the transition proposed to Local Water Done Well, there are risks and potential instability across the water sector, but also vast opportunities. Water New Zealand’s Towards 2050 – Transformation vision for the sector, developed with iwi, community and the broader water industry, has established a powerful strategic foundation for regulatory and planning reform. It is underpinned by a vision for Te Mana o te Wai, community, culture and sustainability, including a holistic approach to water management and environmental and natural resource protection, to support thriving ecosystems, mahinga kai (working the natural resource) and societal wellbeing.

Stormwater reuse is an evolving alternative, but the reliability of stormwater as a secondary water source is low. Climate change and rainfall fluctuations have worsened the predictability of stormwater supply and created challenges for balancing demands without running out or causing issues like flooding. Addressing water scarcity effectively involves optimising wastewater as a dependable, predictable resource, alongside water recycling strategies to minimise discharges into and protect our waterbodies.

Sustainable investment and a thriving circular economy

Over the next 30 years, major investment in water and wastewater infrastructure is forecast to address the widespread deterioration of ageing assets and enable resilience against climate change. The cost of treating water to potable water standards is very high, and on a nation-wide scale may lead to missed cost optimisation opportunities if water asset renewal and upgrade programs are delivered independently, based on homogenous water quality standards and supplies that do not account for regional needs.

Demand is growing for a circular economy in both local and international trade markets. By adopting proactive regulations and investing today, we can mitigate future risk of industry and trade market constraints if circular economies are not embraced.

Water recycling is already happening in New Zealand, but it isn’t always simple.

There are emerging examples of recycled water being used in New Zealand, and evidence of a growth in demand for alternative, climate-resilient supplies, both quality and quantity. However, socio-economic drivers, institutional arrangements and regulatory frameworks and standards are not yet embedded across the sector, and the implementation of formalised recycled water schemes is still rudimentary.

Whilst various international guidelines are voluntarily used in New Zealand, there are disparate approaches to quality controls and management. Not only does the lack of a national standard create inconsistencies, but it also makes it more challenging for practitioners. Without well-defined guidelines for planning, design, operation, and management of recycled water schemes, both councils and customers are reliant upon their own research and discipline to establish workable arrangements for investment and operation of schemes. This takes a substantial commitment of time and resources, is inefficient and costly, and creates barriers to reuse growth, especially in small-scale settings. Further, while compliance with technical standards and consent conditions can be achieved, there is a lack of rigour in quality management systems and ongoing compliance monitoring to ensure the performance is enduring well beyond the first few months after commissioning, when more attention is being paid to careful operation.

How can water recycling become a prominent part of New Zealand’s sustainable future?

The definition, documentation, and implementation of water recycling guidelines and standards would enable a structured facilitation of alternative water supplies for a wide range of uses, through improved planning, delivery and management efficiencies, standardisation and consistency, and better cost certainties. Opportunities for water recycling across New Zealand include but are not limited to industrial (e.g. cleaning/wash-down and processes), irrigation (e.g. public spaces/green belts, agriculture, horticulture, viticulture, animal fodder, non-food crops), supplementing and balancing stormwater flows, and environmental management (e.g. salinity management, drought-proofing vulnerable waterways, aquifer injection). Advanced technologies could even enable qualities suitable for potable consumption and ultra-high purity industrial water (e.g. semi-conductor production and other demineralised water applications).

Progression towards sustainable institutional reform for recycled water planning, design and management is underpinned by several key elements:

• Learning together: Through connection, collaboration and partnership with our communities, iwi, local and international experts; we can develop recycled water standards tailored for Aotearoa, while utilising industry knowledge and standards from around the world. The consultation, communication and education strategy is vital, as well as the importance of acknowledging, understanding and responding appropriately to the risks and concerns raised by New Zealanders.

• Learning from experience: There is no need to need to ‘start from scratch’. Globally, technologies and management systems for all manner of water recycling schemes are very mature and have been operating safely and successfully for decades. Examples of successful documentation that can be drawn on are the Australian Guidelines for Water Recycling, the Victorian guideline for water recycling, the Queensland Water quality guidelines for recycled water schemes, and the California Code of Regulations. New Zealand can build on the extensive experience, research, and knowledge from other water recycling initiatives across the globe, including successes but also lessons learned, risks that materialised, and solutions developed.

• Nation-wide alignment on regulation, adaptable to local conditions: Consistency is critical for quality control and public health. National standards and guidelines would also create efficiencies, optimisation of resources, and prevent isolated approaches to a national solution. There will need to be flexibility too, however, to ensure that planning and consents can be adapted to local environmental conditions, cultural aspects and usage requirements. Strong leadership, a clear definition of roles and responsibilities, and effective nation-wide coordination will be required to ensure an aligned and united approach. A suite of documentation may also be created to supplement recycled water quality standards. These may include pricing policy and investment decision support tools (integrated with wastewater investment planning); standardised Recycled Water Management Plans for streamlining operational controls and risk management; guidelines to support capacity building in planning, design and operations; and bespoke frameworks aligned to Te Mana o te Wai, to ensure cultural values are embedded into wastewater and recycled water planning and management.