Underground Bioretention

Trees are the best filters for our cities. Bioretention cells are designed to treat polluted stormwater runoff from adjacent pavements. Our bioretention system uses the root soil volume and does not take up the extra space that ordinary bioretention does.


Urbanisation is characterised by a high percentage of impervious surfaces, limited green areas and has altered the natural water balance leading to a much greater discharge of waste water and poor-quality runoff. Infiltration in groundwater is reduced and the quality may also be degraded due to the presence of pollutants, which in turn damage aquatic habitats. Limited tree coverage reduces water storage in root systems, the release of water into the atmosphere through transpiration and natural pollution that is filtered mainly through tree roots.

As a result, increased attention is paid to managing the water cycle in urban development. Often referred to as Water Sensitive Urban Design (WSUD) or Sustainable Drainage Systems (SuDS), these are an alternative approach to traditional rainwater management. It’s focused on compensating the effects of overly paved areas and to limit the changes in natural water management by local water reuse and temporary storage. The main principles include the integration of rainwater into the landscape, the protection of its quality and the reduction of peak loads caused by more extreme rain events.


Water sensitive urban design (WSUD) makes use of better urban planning and design to reuse stormwater and prevent it from reaching our waterways by mimicking the natural water cycle as closely as possible. Known practices are: 

Rain gardens that are specially-designed garden beds that filter stormwater runoff from surrounding areas. Rain gardens consist of a shallow planted depression designed to retain or detain stormwater before it’s infiltrated or discharged downstream. Bioretention basins serve the same purpose as rain gardens but with a more technical term that typically describes large projects in community common areas as well as non-residential applications.

Water infiltration units that are designed structural units for submerged use managing two important tasks; subsurface water retention and infiltration. The units combine high storage capacity with an enormous stability for underground use. 

Our underground bioretention system serves both functions; bioretention and underground water storage. A "submerged rain garden", existing of modular units, that uses soil to support large tree growth and provides powerful on site stormwater management through absorption, evapotranspiration, interception and filtration, while not taking up extra space in the crowded city area.

Find your urban tree solution