Rainwater Interception System

Rainwater Interception System for Commercial and Public Buildings roofs and podiums

As space becomes even more limited in the urban environment we need to look to more sustainable ways of managing the flow of rainwater. By using Polypipe rainwater management and source control systems for commercial properties and public buildings roofs and podiums, in conjunction with trusted Terrain drainage pipe systems, building services designers can utilise these areas to integrate effective rainwater management and harvesting at source and control the flow of water at a designated rate into the below ground drainage system.


Dealing with Rainwater run-off


Reducing rainwater run-off adds significant value to Sustainable Urban Drainage Systems (SUDS). By intercepting rainwater at source, it can be used as a resource. The majority of rainfall events in the UK may be less than 5mm in depth, however on the occasions when the depth is much higher, existing commercial and public building systems can struggle. In order to cope with heavier rainfall, you’ll need surface-based systems to provide rainwater storage, treatment, flow control, evaporation and passive irrigation. Each of these systems is critical to the performance of source control drainage systems.


The Rainwater Interception System comprises of the following components:


  • High strength modular cells
  • Robust geotextiles (to provide treatment)
  • Geomembranes
  • Rainwater outlets incorporating flow control devices and engineered Terrain Soil and Waste PVCu and HDPE systems


It can enhance the effectiveness of both ‘green’ and ‘brown’ roof applications, and can even provide a ‘blue’ roof attenuation system. Due to the inherent strength of permavoid modular geocellular units, this system can be incorporated into a wide range of SUDS solutions.


To find out how our Rainwater Interception System could benefit your commercial building please call our Technical Team on 01509 615100.

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For further information please see our Applications & Benefits and Roof Applications pages.

  • Permavoid (85 and 150mm)

    Permavoid has modular cells that link together to form an interlocking raft of exceptional high compressive and tensile strength for rainwater infiltration or storage / attenuation.

  • Geomembrane

    An impermeable membrane for wrapping around Permavoid structures to form watertight tanks.

  • Rainwater Interception Outlets

    We’ve an extensive range of rainwater outlets for flat roof and balcony applications for commercial, industrial and public sector bulding developments.

  • Terrain Soil and Waste Systems

    Terrain pioneered the development of solvent-weld pipe systems and fittings over 50 years ago and we are recognised worldwide for our premium product range and knowledge.