Our Services
Wastewater treatment, water tanks, drainlaying and servicing, supplied, installed, and maintained by one family-run team. From a single home on a tricky site to large commercial and community projects, we handle the whole job and back it for the long term.
Wastewater Treatment Systems
We specialise in advanced wastewater treatment for sites that aren't connected to mains sewerage. These are the sites that need cleaner effluent, a smaller footprint, and rock-solid reliability. After years of working the hardest sites in the country, we went looking for the best technology available and brought Kubota to New Zealand through our partnership with True Water.
Residential
For homes, lifestyle blocks, and difficult or sensitive sections, we supply and install advanced secondary treatment systems including the Kubota KZII, the world's smallest modular treatment plant, built for a 50-plus year life with no internal moving parts.
Best suited to:
New builds and replacements on un-reticulated sites
Steep, tight-access, or coastal/sensitive sections
Anyone who wants a quiet, odourless, low-maintenance system that protects their family and the environment
Commercial & Community
For developments, businesses, and communities, we deliver the full Kubota commercial range: packaged, modular plants from around 5,000 litres up to 1 million litres a day, including MBR systems that produce Class A reuse-quality water. This covers the capacity band where most New Zealand packaged plants stop and bespoke civil-built plants begin: near-municipal performance, at packaged-plant speed, cost, and footprint.
Suited to:
Wineries, lodges, hotels, restaurants, and tourism venues
Subdivisions and cluster systems where reticulation isn't available
Service stations, schools, retirement villages, holiday parks, and more
On larger projects, our local delivery team is backed by the engineering depth of True Water and the manufacturing pedigree of Kubota.
Water Tank Supply & Installation
We supply and install quality water tanks for rainwater capture and storage, sized to your roof area and usage.
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Rainwater harvesting and storage
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Sizing to suit your roof and demand
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Supply and installation as a complete job
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Detention and retention tanks where councils require them
General Drainlaying
Our registered drainlaying team handles the groundwork that makes everything else work, for both residential and commercial sites.
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Stormwater and sewer drainage
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Site and subsoil drainage
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Connections and reticulation
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Retention and detention systems for council compliance
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Excavation and groundworks for treatment systems and tanks
Servicing & Maintenance
Advanced treatment systems need scheduled servicing to keep performing and stay compliant. It's part of owning one, not an optional extra. We keep your system, and your council paperwork, in good standing.
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Scheduled servicing on the right interval for your system and consent
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Performance checks and reporting
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Remote monitoring and diagnostics where available
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Proactive repairs and parts
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Servicing for the systems we install, with national reach through our network
Where we work
A Gradient Drainage is based on Waiheke Island, where we got our start, and works across the Hauraki Gulf and throughout New Zealand. Wherever your project is, our local team is backed by the True Water and Kubota network for engineering, supply, and large-project support.
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From a single home to a large development, we'll help you choose the right system and do it properly. Send us your details and plans, and we'll get straight back to you.