Crate Stormwater Storage Systems – Aquavoid-Metro


The Naylor Aquavoid-Metro range of storage crates and attenuation crates provides an economic, versatile storage system for most Water Management Attenuation uses. Aquavoid- Metro (400kN/m2) is ideal for general use. The Metro crate is 1.2m x 0.6m x 0.3m and sits on a purpose designed base plate so open crates can then be stacked on top to form a larger void. The units have eight access points per crate making them very versatile and offering multiple options for connections, silt channels and inspection/maintenance possibilities. The Aquavoid is supported by Vortex Flow Controls, geotextiles and geomembranes.

Aquavoid-Metro has been designed specifically to meet the needs of sustainable construction as advocated by the UK Government and provides the means for rainwater, collected from roofs and pavements, to be infiltrated into the soil. The sewage system is relieved of additional loads and drying out of the sub-surface can be prevented.

Aquavoid-Metro systems can be used as a soakaway: the rainwater collected through pipes from the roof and/or road can be slowly infiltrated into the soil. By infiltrating relatively clean water into the soil, the drainage system is relieved and drying out of the sub-surface can be prevented. Infiltration of rainwater is part of sustainable construction as advocated by the UK Government.

Aquavoid-Metro can also be used as an attenuation system: when the normal drainage systems cannot cope with the volume of surface water this is diverted into the Naylor Aquavoid-Metro storage system and released slowly after the storm has passed avoiding localised flooding.

When creating a soakaway, these underground storage units are wrapped in a heavy duty non-woven, needle punched geotextile to allow water discharge to the subsurface, but prevent any soil or sand particles to go through.

The construction of an attenuated structure is almost identical to that of a soakaway with the exception of the structure being wrapped within a geomembrane as well as a geotextile to create a sealed system allowing temporary storage of the stormwater until the storm has passed.

CIRIA C737 Guidance: The new CIRIA C737 guidance for the structural design of such systems was published in 2016 and details far more stringent testing regimes for the crates compared to its predecessor.

Advantages & Benefits of Naylor Aquavoid-Metro:

  • High Bearing Capacity, sufficient for pedestrian use
  • Large Storage Capacity, 95.5% voids
  • Economic to install & maintain
  • Prevents extreme peak flows to main drainage and water purification systems
  • Rainwater is “cleaned” by geotextile surround
  • Decreases flooding during heavy rain fall
  • Promotes the balance in the groundwater position
  • Decreases environmental problems caused by development
  • Flexible – can easily be expanded in all directions
  • Suitable for high and low groundwater situations
  • Inlets/Outlets: 110 160 & 200mm as standard, other diameters require our adapter unit

Typical Applications:

  • Typical Applications:
  • Car Parks
  • Landscaped Areas
  • Recreational Areas
  • Amenity Areas
  • Caravan Sites
  • Commercial Sites

Additional Information:

Crate Volume (Metro) is 0.216m3, effective capacity @ 95.5% is 206 litres (4.629/m3)

Base Plate Volume is 0.014m3, effective capacity @ 95.5% is 13.7 litres

Additional Information

Crate Volume 0.216m3, effective capacity @ 95.5% is 206 litres (4.629/m3)

Base Volume 0.014m3, effective capacity @ 95.5% is 13.7 litres