Why SUDS?
Sustainable Drainage Systems (SUDS) are techniques for the management of stormwater which seek to replicate natural undeveloped catchment. SUDS are required to give a sustainable solution to the management of rainwater runoff from roofs and impermeable hard landscaped areas such as car parks, service yards and access roads. Government policy through PPS25 (Planning Policy Statement) states that it is essential for the “integration of sustainable drainage systems into the overall site concept and layout”. Furthermore, “the planning system can drive the use of sustainable drainage systems by persuading developers to adopt sustainable drainage systems wherever practicable, as part of all future development, if necessary through the use of appropriate planning conditions”.
The Permavoid Source Control System comprises a series of treatment phases which have been specifically developed to provide the ideal solution to meet the requirements of all current guidelines and legislation relating to SUDS, whilst incorporating Pervious surfacing and traditional impermeable surfacings such as macadam, asphalt, concrete and standard block paving.
The key SUDS principles:
1 Source control
Sustainable drainage systems that control surface water run-off as close to its origin as possible are termed ‘source control’ systems. This technique minimises changes in the volume and rate of surface run-off from developed sites and thereby minimises flood risk and other environmental damage. Additionally, SUDS may offer an element of pollution control as well as ‘attenuation’ - where infiltrated water is stored before its controlled release.
2 Management train
These levels of control and treatment result from a series of techniques (‘management train’) that integrate with one another to gradually reduce levels of pollution, volume and flow rate prior to discharge.
3 Water quality
Removing pollution from run-off is an important part of SUDS design. The use of SUDS to control pollution and replace oil separators is highlighted in the most recent edition of Pollution Prevention Guideline PPG 3 published by the Environment Agency (2006).
4 Amenity and biodiversity
Trees (the urban forest) are an important element in the biodiversity of urban areas and improve amenity by providing enhanced aesthetics, cooling and shading. Permavoid systems can be designed to protect and enhance the health of existing and new trees by protecting the roots systems and providing irrigation and aeration to the soil.
5 Rainwater harvesting
Rainwater harvesting involves collecting rainwater in storage tanks and reusing it for non-drinking purposes such as watering gardens or flushing toilets. Rainwater harvesting can be incorporated into SUDS using Permavoid’s components.
