SlabTank by QPOD

Integrated Stormwater Storage Within Your Foundation

Designed to manage stormwater where space is limited, SlabTank integrates water storage directly beneath slabs, driveways, and hardstand areas, reducing the need for separate tanks and simplifying site design.

SlabTank by QPOD

CodeMark certified.

CodeMark certified, making design, approval, and specification straightforward.

What is SlabTank™?

SlabTank™ is a modular Codemark-certified stormwater attenuation system designed to sit beneath slabs, driveways, and other hardstand areas, allowing you to store and manage water within space that already exists on site.

Instead of adding separate tanks, SlabTank integrates directly into your build, helping simplify layouts while supporting compliant stormwater design.

Built for flexibility, SlabTank is a natural fit for in-slab installation, but works just as effectively under driveways, patios, and decks.

The system uses a lightweight, modular design that fits within standard formwork without requiring special footings or complex installation. With two standard sizes (630L at 220mm high and 850L at 300mm high), it adapts easily across a wide range of applications.

Its flat profile aligns with typical raft slab modules (approx. 1100mm width) and integrates cleanly with reinforcing steel and plumbing during setup.

With no interconnections required between tanks, SlabTank simplifies plumbing, reduces potential leak points, and allows flexible placement even in more challenging ground conditions.

Distribution Chamber

The spigot from each tank is connected via a flexible pipe coupling to a single pipe which leads to the distribution chamber. This chamber is designed to slowly release the water from the tanks into the stormwater system.

SlabTank™ 850L

The SlabTank™ 850L is the larger capacity option and is 3029cm long by 1090cm wide and 300cm high. These tanks provide peace of mind, with no inter-connections in the slab to mitigate the risk of leaks within the foundation.

SlabTank™ 630L

The SlabTank™ 630L is the smaller capacity option and is 3029cm long by 1090cm wide and 220cm high. These tanks have a 13mm thick wall section, making them very sturdy and robust to get around on during construction.

SlabTank came from years of conversations with builders and designers who were uneasy about what was happening inside their slabs. Interconnections, penetrations, the risk of leakage. It all added complexity and doubt. With QPOD, we had already rethought what sits within the slab. SlabTank was the natural next step. A way to simplify in-slab water attenuation and remove the uncertainty around interconnections.

Peter Crawshaw

General Manager, QPOD Earth-Friendly Foundations

Why SlabTank?

Stormwater usually ends up dictating parts of a design. Tank locations, pipe runs, lost space. SlabTank flips that around by working within the footprint you already have.

Makes use of existing space
Integrates storage beneath slabs, driveways, and hardstand areas instead of carving out room elsewhere on site.
Simplifies site planning
Reduces the need for separate tanks, helping keep layouts cleaner and easier to coordinate.
Straightforward to install
Modular units drop into standard formwork and can be set out alongside reinforcing and services.
Flexible across different projects
CodeMark cerified and suitable for residential builds, including sites where space is tight or irregular.
Built for long-term use
Designed to sit within the structure, protected from exposure and aligned with the lifespan of the build,
Confidence that lasts
Full warranty coverage for up to 50 years – find out more about the warranty coverage here.

How SlabTank Works On Site

SlabTank is designed to slot into a project without introducing additional complexity.

Each tank sits within standard formwork, aligns with reinforcing, and is enclosed as part of the concrete pour.

No Interconnections

Each SlabTank module works independently, so there’s no need to link tanks together.

That removes a common failure point and anxiety, simplifies installation, and gives you more flexibility with layout. Tanks can be positioned where they’re needed, even in tighter or irregular spaces, without redesigning the system around connections.

Less plumbing. Less risk. Easier to get right on site.

Low Profile/Large Volume

Big storage, minimal height.

SlabTank is designed to sit within standard slab depths while still delivering the volume required for stormwater attenuation — without pushing the rest of the design around it.

Two Size Solutions

Two tank depths available: 220mm (630L) and 300mm (850L).

Ready For Anything

Designed for New Zealand sites, SlabTank is suitable across TC1, TC2 and TC3 ground conditions.

It works alongside standard foundation detailing, giving you a practical way to incorporate stormwater attenuation without overcomplicating the design.

Designed for Strength

Built off the QPOD platform, SlabTank is made from MDPE uses the same structural leg design proven in slab foundations across New Zealand.

It’s engineered to carry load where it matters, so it integrates cleanly under slabs, driveways, and other load-bearing areas without introducing weak points into the system.

CodeMark Certified

SlabTank is CodeMark certified, providing a recognised pathway to compliance under the New Zealand Building Code.

It gives designers and builders confidence that the system has been independently assessed and can be specified with clarity across projects.

Download Certificate here.

Design and Technical Overview

SlabTank integrates stormwater storage directly beneath your slab, driveway, or subfloor using a modular, no-interconnection system.

Modular units placed within slab footprint
Connected to a central distribution chamber
Stores and controls stormwater at source
No separate tanks or remote systems required
Designed to work alongside QPOD or standalone

Two configurations give flexibility depending on slab height and storage requirements.

Length: 3290mm
Width: 1090mm
Height options: 220mm / 300mm
Storage: 630L / 850L per unit

Installed as part of the slab process. No separate tank install required.

SlabTank integrates directly within a standard TC2 slab, providing on-site stormwater storage without changing the way the slab is built.

SlabTank can be installed beneath driveways and hardstand areas, turning otherwise unused space into functional stormwater storage.

SlabTank can be used beneath suspended floors or pile systems, providing stormwater storage without interfering with structural elements.

Calculate Your Water Attenuation

Stormwater attenuation is simply the amount of water your site needs to temporarily store before it’s released.

Start by entering your required volume (in litres), typically provided by your engineer or council. The calculator will then work out how many SlabTank units are needed to meet that requirement, along with the total footprint under your slab.

In the SlabTank Stormwater Attenuation Calculator you can choose between 630L or 850L tanks, or a combination of both depending on your layout and depth constraints. Each tank shares the same footprint, so the system scales cleanly across your slab.

SlabTank Stormwater Attenuation Calculator

QPOD and SlabTank provided a well engineered, practical solution that integrated seamlessly into the build, particularly with the in-slab water storage in the garage. I think SlabTank™ is going to be a game changer for us at Landmark Homes.
The engineering support and flexibility from the QPOD team made the process straightforward and the Installation team seem to feel it went smoothly.
A solid system and a reliable team to work with.

Tony Lafferty

Director / Construction Manager, Landmark Homes Hawke's Bay

Rainwater, Handled On Autopilot

SlabTank manages what happens below the slab.
RainHarvester takes care of what happens next.

The SlabTank RainHarvester Auto is an optional a fully automatic system that draws rainwater from your tank and supplies it to your home or site, switching to mains when needed and back again when levels recover.

It prioritises rainwater first, using what you’ve already captured, and only brings in mains supply when it’s required to maintain consistent pressure and flow across the home.

No manual changeovers.
No monitoring tank levels.
No interruption to supply.

When tank levels drop, the system responds automatically, maintaining service without the user needing to step in or even notice. When the tank refills, it switches back, returning to rainwater as the primary source.

This removes the usual complexity around rainwater systems, where multiple components, manual switching, or uncertainty can creep into the setup.

It’s designed to pair directly with SlabTank, creating a complete solution from storage through to supply. One system that manages water where it’s stored, and how it’s used, without adding extra layers to design, installation, or operation.

Learn More About RainHarvester Auto