It is not always possible to create required shallow attenuation volume due to limited space. The extra volume needs to be found elsewhere in the project. With Permavoid MD this extra volume can be created by forming big attenuation tanks deeper in the ground. 


Permavoid MD for deep applications

The tried and tested Permavoid MD range is designed to provide surface water retention, surface water attenuation or surface water infiltration at a variety of depths.

The Permavoid  range of modular cell systems are designed with a 95% void ratio to retain large volumes of water run-off. The Permavoid MD modular cells can be built up to form a structure of any shape or size making them ideal for narrow strips or restricted areas. The modular cells have unique rounded corners which enables ease of handling and reduces the likelihood of punctures to membranes. The range can be designed for both trafficked and non-trafficked areas. At the end of their life the modular cells are fully recyclable. Permavoid MD is produced from 100% recycled polypropylene.

The perfect blend of technology and sustainability.

Create volume by forming big attenuation tanks deep in the ground 


How does it work?

With the structural modular Permavoid MD cells we are able to build underground waterstorage tanks into any volume or shape, without losing the use of land above the tank due to the high pressure resistance. This underground structure will attenuate or infiltrate the rainwater depending on choice of wrapping.


Strong benefits for the city.

Integral watermanagement

The Permavoid MD units have integrated connection points for pipe and inspection points and can be incorporated in an integral water management system.

Smart design

The long and narrow design of the Permavoid MD tank aims at maximum surface area for rapid infiltration to groundwater.

Floating mat

To be sure the water quality in the deep attenuation tank is clean enough to be safely infiltrated or reused, we developed an extra cleansing step in the MD unit: the floating mat. It traps any residual hydrocarbons and oils in the water. 

No on-site assembling

The Permavoid MD units will arrive ready to install on-site, which will save expensive labour on site. 

Maximum water attenuation capacity with the Permavoid MD units.

Inspiring projects

Get inspired by these projects.

From domestic soakaway to large scale industrial development installations; we are proud of the projects we have realized with our partners throughout the years.


Have a look at a selection of the Permavoid MD projects installed globally and learn more about the technology in our civil brochure. 

View all inspiring projects

We have built a reputation

Find your local distributor nearby.

Permavoid source control ensures that no precious water goes to waste by catching, storing and reusing stormwater for irrigation, evaporation and infiltration. Find your local Permavoid distributor here to learn more about the technology and become part of the international movement.