As New Zealand moves toward more stringent stormwater management, it is also entering a new era of building self-certification and proportionate liability. Upcoming changes will allow more qualified plumbers and drainlayers to self-certify their work, reducing the need for council sign-off at each stage. While this streamlines the process, it also shifts greater responsibility, and risk, onto the professionals delivering the work. 

In this environment, the technical integrity of in-slab water detention systems has never been more critical. 

Aquacomb and other in-slab systems are excellent for managing stormwater discreetly, but they only work as intended if a strict ‘test and verify’ protocol is followed during installation. 

The 2026 Stormwater Conference brought together councils, engineers, consultants, contractors, and industry leaders from across New Zealand and Australia to tackle one of the sector’s biggest challenges: how we build more resilient communities in the face of increasing climate and infrastructure pressure. 

This year, the Watersmart team was proud to contribute not only through our exhibition presence, but also through two technical presentations that explored practical, real-world approaches to stormwater resilience, flood mitigation, and distributed water management. 

Our exhibition stand showcased Watersmart’s broader stormwater ecosystem, including flood mitigation, detention and retention systems, permeable infrastructure, water reuse, and resilience-focused solutions designed to support both public infrastructure and private developments. The conversations throughout the event reinforced a growing industry shift toward integrated, multi-layered stormwater responses rather than relying solely on traditional pipe networks. 

Reimagining Kerb Infrastructure Through Permeable Design 

Klaudia presented findings from the City of Merri-bek permeable kerb and channel trial, developed in collaboration with the University of Melbourne and Porous Lane. 

The presentation explored how conventional kerb and channel systems rapidly collect and concentrate runoff into underground infrastructure, increasing downstream pressure, disconnecting water from urban vegetation, and contributing to flooding risk. 

The permeable kerb and channel approach rethinks this model entirely. Instead of treating stormwater as waste to remove as quickly as possible, the system allows water to spread, slow down, infiltrate locally, and support surrounding soil and vegetation systems. 

Field study results from the Merri-bek trial showed: 

• Up to 81% runoff retention across monitored rainfall events 

• Significant peak flow reduction 

• Improved soil moisture and urban tree support 

• Strong performance despite low-permeability clay soils 

• Reduced clogging risk through distributed inflow design 

• Greater flexibility and impact resistance compared with traditional concrete kerbing 

The presentation also highlighted the role of recycled tyre materials within the system and the growing importance of designing infrastructure that works with natural water processes rather than against them. 

As councils continue looking for scalable low-impact stormwater solutions, interest is now growing around potential New Zealand pilot projects. 

Flood Resilience Beyond Infrastructure Alone 

A second presentation delivered by Julian and Elliot focused on the consenting pathway, design methodology, installation process, and testing regime behind the flood barrier systems installed in central Auckland last year. 

The presentation explored how the barriers were engineered and sized to respond to site-specific flood risk, alongside the practical realities of installation, commissioning, and long-term resilience planning. 

Importantly, the discussion extended beyond physical infrastructure alone. 

Part of the presentation focused on Watersmart’s ongoing collaboration with the insurance and finance sectors over the past 14 months, helping educate stakeholders on resilience solutions that support flood prevention, recovery, and long-term community protection. 

Key themes included: 

• Shifting focus from reactive claims toward prevention and asset protection 

• Supporting post-flood recovery through investment in resilience infrastructure 

• Educating communities around practical flood mitigation solutions 

• Encouraging sustainability and resilience lending pathways 

• Creating stronger collaboration between the stormwater, insurance, and finance sectors 

One of the strongest messages throughout the session was that stormwater resilience cannot sit within a single industry alone. Preventing flood impacts requires alignment between infrastructure, policy, finance, insurance, and community education. 

Continuing the Industry Conversation 

For Watersmart, events like the Stormwater Conference are not simply about showcasing products. They are an opportunity to contribute to the wider industry conversation around resilience, sustainability, and the future of water infrastructure. 

As climate pressures continue to increase, the industry is being challenged to think differently about how stormwater is managed, how communities are protected, and how infrastructure can work more effectively with natural systems. 

Being able to contribute practical project experience, technical research, and cross-sector collaboration discussions is an important part of helping move that conversation forward. 

Watersmart delivered a customised 5,250L Aquacomb detention system for a high-end residential build in Lower Hutt, overcoming tight under-house and under-deck space constraints. Working closely with Jason Brown Plumbing, the system was designed around structural piles and site-specific stormwater requirements to provide a discreet, compliant solution where conventional detention options were limited.

Protect your property before the next flood event. Watersmart supplies and installs engineered FloodFree flood barriers across New Zealand for residential, commercial, and council applications.

This Auckland Council project was delivered by Ventia, who are leading the way in integrating low-carbon, sustainable materials into public works. Ventia introduced Porous Lane as an alternative to a traditional timber boardwalk and tree root bridging detail to improve long-term performance, reduce environmental impact, and enhance safety for users on a steep, tree-sensitive slope. Watersmart was engaged to support the delivery of this solution. 

Over the past 12 months, 4,466,750 litres of Aquacomb water storage has been installed across New Zealand. These have managed an estimated 220 million litres of water over the year. 

This figure is based on internal system capacity calculations across approximately 3,800 installations between 1 April 2025 and 31 March 2026. It reflects a combination of both detention and retention. In simple terms, that is water being temporarily stored and released in a controlled way, or held for non-potable reuse within the property. 

On its own, each system contributes a relatively small volume. But when you step back, the scale becomes clearer. Across thousands of sites, this works out to roughly 60,000 litres per property last year. 

Read more about how Auckland Transport used prous lane to create resilient and future proofing footpaths for the Eastern Busway Project.

Learn how this homeowner included water recycling into his home with Hydraloop to fill toilets and laundry water.

Learn how a Piha family saved 37,250 litres of water (30% of total usage) in 18 months using the Hydraloop recycling system. Perfect for off-grid water security.

Around the world, leading cities are adopting a more integrated approach: designing urban environments to behave like sponges — absorbing, storing, filtering and gradually releasing rainwater rather than immediately channelling it away.

Porous Lane driveway installed on in Henderson Valley to prevent water pooling and help stormwater management.

In New Zealand’s urban centres, square metre rates have reached a threshold where every centimetre of a site plan must justify its existence. For developers and specifiers, the pressure is two-fold: construction costs continue to climb (Stats NZ reporting a 3.6% increase in residential costs in the year to September 2024), while land availability remains at a premium.

Porous Lane tree pits installed on Mayoral Drive, Auckland CBD to encourage tree growth and reduce maintenance.

The Watersmart Innovation Hub: Solving Tomorrow’s Water Challenges Today. Opening a space for the industry to learn more about how to build water resilient futures with Watersmart.

Hot, dry summers put pressure on mains water, but slimline rainwater storage makes every downpour count. This guide covers FenceTank, stormPANEL, and Silo systems that fit tight sites while supporting gardens, outdoor play, and everyday non-potable use. Learn how to plan capacity, connect plumbing compliantly, and scale storage before restrictions hit.

Plan smart water detention and rainwater reuse systems for NZ summer. Compare tanks, Aquacomb, lead times, capacities, and council compliance.