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.

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. 

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.

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.

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