Most stormwater treatment devices operate out of sight. Whether it’s a catchpit filter, cartridge filter or treatment system, their role is the same: to help prevent contaminants from entering our waterways.

Without regular maintenance, these devices gradually lose their effectiveness. Sediment, metals and hydrocarbons can bypass treatment systems and make their way into nearby streams, rivers, harbours and beaches. The impacts are often difficult to see immediately, but they can have lasting environmental consequences.

That’s why we’re proud to award Calder Stewart our tenth Responsible Stormwater badge.

Why the badge exists

We created the Responsible Stormwater badge to recognise businesses that demonstrate a genuine commitment to maintaining their stormwater assets and protecting New Zealand’s waterways.

We also want to raise awareness of an often-overlooked issue. Stormwater systems only work as intended when they are maintained. Regular servicing is an important part of protecting the environment and meeting compliance obligations.

To qualify, a customer must have regularly maintained their stormwater systems with Dutton Stormwater for at least two years, or have committed to a long-term scheduled maintenance programme across all devices.

Many sites maintain their devices because they are required to do so under a resource consent. That’s important. The customers we recognise take an additional step by treating stormwater maintenance as an ongoing responsibility, not simply a compliance requirement.

The badge gives recipients a way to demonstrate that commitment to their customers, stakeholders and communities. It reflects a proactive approach to protecting waterways and managing stormwater assets responsibly.

You can’t apply for it

There is no application process. Dutton Stormwater awards the badge when a customer has demonstrated a sustained commitment to stormwater maintenance and environmental protection. That approach helps ensure the badge remains meaningful and reflects genuine action over time.

Meet Calder Stewart

Calder Stewart is one of New Zealand’s leading property and construction groups, specialising in industrial and commercial developments. The business began in Milton, Otago, in 1955, when Lance Calder and Bruce Stewart established what would become a family-owned organisation operating across land development, design-build, manufacturing and construction, across the breadth of NZ.

Calder Stewart has been a Dutton Stormwater customer for several years and during that time, we have serviced their sites nationwide.

Why Calder Stewart, and why now

Calder Stewart’s commitment to responsible stormwater management has been demonstrated through:

• Years of regular maintenance, significantly exceeding our two-year qualification requirement.
• An ongoing commitment to scheduled maintenance across its stormwater assets.
• Maintaining devices beyond minimum compliance requirements.
• A proactive approach to recommendations and asset management that helps keep systems performing effectively.

“The best stormwater systems in the world can’t protect our waterways if they’re not maintained. What stands out about Calder Stewart is the consistency of its commitment. For years, they have taken a proactive approach to maintaining their stormwater assets and ensuring their systems continue to perform as designed. This recognition reflects a genuine commitment to environmental responsibility and long-term stewardship.” Says Grant Buckingham, Business Development Manager, Dutton Stormwater.

Compliance is the floor

The badge was presented on 21 October 2026, by Grant Buckingham, Business Development Manager from Dutton Stormwater to Chris Roche, National Facilities Manager and Phoebe Pope, Facilities Manager. Calder Stewart can now display the Responsible Stormwater badge across its communications, including its website, tenders and marketing materials.

A resource consent establishes the minimum standard expected of a site. Protecting our waterways requires organisations that view that standard as the starting point, not the finish line.

Calder Stewart has consistently demonstrated that approach through its commitment to maintaining the performance of its stormwater assets and taking ownership of its environmental responsibilities.

By recognising organisations that lead in this area, we hope to encourage greater awareness of the role stormwater maintenance plays in protecting the streams, rivers and harbours that connect our communities.

Congratulations to the Calder Stewart team.