Water Detention

Aquacomb© on site detention (OSD) is New Zealand's first in-slab stormwater system to come in a pre-packaged kit form, for simple and quick installation. Our system saves days in construction time and significantly reduces building costs.

The system is used in any standalone, terrace or apartment construction requiring on-site stormwater management. It can be designed into any type of slab construction and is especially suited to waffle pod slabs used in housing. The Aquacombs© can be located in the buildings slab or under any hard ground surface like driveways or under decks, or behind retaining walls or even stacked on their edge under soffits. 

Unlike traditional solutions the entire Aquacomb© system is hidden from view meaning no over ground pipes and no big water tanks taking up space on your or your customer's property.


The Aquacombs© are installed by an approved plumber or drainlayer to ensure it conforms with council's stormwater regulations. Work with your architect or engineer to design as many Aquacombs© into your concrete slab as necessary to meet the required or desired water storage capacity.

Aquacomb© OSD is an established and accepted fully modular system, which has over 10,000 trouble free residential construction installations over the past 10 years throughout Australia, and being accepted as the problem solving solution for stormwater across Auckland and New Zealand.

Advantages of Aquacomb©

No Excavation Costs

Traditional OSD solutions need to be buried in ground. This requires excavation and trucking costs to remove and dispose of dirt, possibly craneage costs to place large tanks, and takes time, money and space.
© simply replaces the styrofoam pods in your concrete slab or can be located under any hard ground surface like a driveway or under decks, so no extra excavation is needed.

High Invert Levels

Where there is a high invert level for connection to the public stormwater system, Aquacomb© is the solution as the units are placed at grade therefore minimising any issues around achieving appropriate falls required.

Better Durability

Above ground solutions are susceptible to physical damage from outside forces, and below ground tanks, even if reinforced, can be susceptible to crushing if too much weight is placed over them at any point in their life. Underground tanks also have the issue of 'popping up' out of the ground if the groundwater level rises faster than the tank can fill up.
Rated to withstand 2 tonne external force per unit, Aquacomb
© is both protected from outside forces and is permanently embedded in your concrete foundation so does not move or shift at any stage in its life.

Combined Use System

Aquacomb© can be installed in the slab and be used for combined detention and retention. Depending on if you have a larger detention requirement or a large retention need you can customise how many aquacombs you allocate each purpose. One product, one system, can fill both needs at the same time.

What is Water Detention?

Storm water detention tanks temporarily store rainwater collected from your roof and other hard surfaces on your property after extreme rainfall events and release the water into the council stormwater system at a much slower rate.


Temporarily storing or “detaining” the water and then slowly releasing it over a period of time reduces short term peak outflows from your property and minimises the impact of the water on the local environment, reducing the risk of local flooding.

Since a city has thousands of homes discharging rainwater into the public stormwater facilities, regulations now ensure new homes do not add to this water volume and overwhelm the stormwater system. Councils require a certain volume of water detention capacity but do not require any particular method of achieving it. 

Flexibility of your Water Detention Solution

Aquacomb© has the massive advantage over other large water storage solutions in that it is modular and can be tailored to fit virtually any space and any water storage requirements. 
For industrial uses, Aquacomb
© is so much easier to install than a single large tank as they can be brought in one by one into any location and arranged in a plethora of ways to best fit your space. Much less engineering is needed when installing Aquacomb© compared to single large tanks, as they can fit into existing infrastructure such as under a floor-slab or car-park.

What material is best for detention solutions?

Concrete or Plastic?

Some people initially think that concrete, being strong and tough, would be the best material to use for water storage. However concrete has many disadvantages over a plastic like PE.

1) Concrete is porous and will lose water over time. Polyethylene plastic is not porous so water will never escape through the tank walls.

2) PE plastic is much lighter than concrete in any application, meaning a plastic tank is much easier and much cheaper to install than a concrete tank.

3) Polyethylene is extremely inert (non reactive) so it will never rust or corrode and it can never rot or degrade in place. This also means it is safe for drinking water as the plastic can never flake off or dissolve into the water.

4) PE plastic is 100% recyclable so if it is ever taken out in the future it can be reused or recycled, while a concrete tank would just be smashed and sent to hard fill.

Contact Us

Email enquiries:

Phone enquiries: Call 0800 11 0808

Chris Coulam - Subdivisions (Milldale / Paerata etc)

Matt Comber - Rest of Auckland

Munya Chitongo - Outside Auckland

Builders, Specifiers, Homeowners - want to find out more?

Give us a call today.

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