What is a Sustainable Urban drainage system (SuDS)?

UKDN advice temporary thumbnail

Sustainable urban drainage systems (SuDs) aim to take a natural (and therefore sustainable) approach to managing drainage.

With more and more vegetation and permeable surfaces being replaced by concrete, paving or roofed structures, less surface water is absorbed into the ground and is directed to the surface water drains.

Instead of channelling surface water through a network of pipes to a watercourse, sustainable systems slow and hold back the water, allowing natural processes to break down pollutants, and release it in a more controlled way.

This reduces the impact of new and existing developments on surface water drainage, and in turn minimises the chances of flash flooding in extreme weather conditions.

SuDS techniques include:

  • green roofs (covered with vegetation)
  • permeable surfaces
  • infiltration trenches, filter drains and filter strips
  • swales – shallow drainage channels
  • detention basins, purpose-built ponds and wetlands

Benefits of SuDS

  • preventing water pollution
  • slowing down surface water run-off and reducing flood risk
  • reducing the risk of sewer flooding during heavy rain
  • recharging groundwater in areas prone to drought
  • providing habitats for wildlife in urban areas
  • creating green spaces in urban areas.