What if the biggest stormwater challenge facing New Zealand isn't flooding itself—but the way we think about managing it? 
 
That was one of the key themes explored at a recent Engineering New Zealand event hosted at the WaterSmart Innovation Hub, where engineers, urban designers, planners, and infrastructure professionals came together to discuss the future of stormwater management in Aotearoa. 

Delivering a durable footpath while protecting mature trees 

Elliott Reserve presented a common challenge for urban infrastructure projects: how to construct a new footpath through an area with established tree root systems without compromising either the asset or the trees. 

Recent changes to New Zealand's plumbing and drainlaying legislation mark an important shift in how compliance is managed across the construction industry. 

With self-certification expected to become available for a wider range of low-risk plumbing and drainlaying work, responsibility for verifying compliance is moving closer to the people who design, install and commission these systems. 

Recent headlines around rising water charges and major infrastructure investment programmes have reignited discussion about the future of water in New Zealand. But beyond the cost of infrastructure lies a bigger question: what role can buildings themselves play in supporting the performance and resilience of our water networks? We explore how rainwater harvesting, water recycling, and on-site stormwater management are changing the way we think about the relationship between buildings and water infrastructure.

Following previous flooding events that impacted a residential basement carpark in Takapuna, the homeowner engaged Frontline Projects to deliver a permanent flood mitigation solution capable of protecting the property from future stormwater ingress. 

Watersmart was engaged to supply, install, commission, and test a FloodFree Concealed Flood Barrier system, providing automatic flood protection while maintaining the appearance and functionality of the existing driveway. 

El Niño is almost certain. Scientists put the probability at 95%, with modelling suggesting this event could rival or exceed anything previously on record. For New Zealand, that means compounding pressure across drought, intense rainfall, and water quality, often in the same season. Here is what that means for the buildings and developments we are responsible for, and what good water management looks like in response.

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. 

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.