What is a Sustainable Urban Drainage System (SuDS)?

UKDN advice temporary thumbnail

Sustainable urban drainage systems (SuDs) offer a natural approach to managing drainage.

When vegetation and permeable surfaces are replaced by concrete, paving or roofed structures, less surface water is absorbed into the ground and more 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 building developments on the surface water drainage, which in turn minimises the chances of flash flooding in extreme weather conditions.

SuDS techniques include

Green roofs (covered with vegetation)

Ogden Elementary School“Ogden Elementary School” by orijinal is licensed under CC BY 2.0

Permeable surfaces

P1150699“P1150699” by avatarr8 (old) is licensed under CC BY 2.0

Infiltration trenches, filter drains and filter strips

Einstein Infiltration trench“Einstein Infiltration trench” by Montgomery County Planning Commission is licensed under CC BY-SA 2.0

Swales – shallow drainage channels

BDEER_55thSt_SwaleAndInlet_2014_05_30“BDEER_55thSt_SwaleAndInlet_2014_05_30” by Aaron Volkening is licensed under CC BY 2.0

Detention basins, purpose-built ponds and wetlands

LoomisProfessional_detpond_Oct2012“LoomisProfessional_detpond_Oct2012” by Aaron Volkening is licensed under CC BY 2.0

Benefits of SuDS

  • prevents water pollution
  • slows down surface water run-off and reducing flood risk
  • reduces the risk of sewer flooding during heavy rain
  • recharges groundwater in areas prone to drought
  • provides habitats for wildlife in urban areas
  • creates green spaces in urban areas.