Sustainable drainage systems (SuDS)

Sustainable Drainage Systems (SuDS) mimic natural drainage to manage surface water run-off from a development. SuDS allow for the collection, storage and treatment of surface water to reduce flood risk caused by development. SuDS generally replace traditional underground, piped drainage systems. They can integrate into both rural and urban developments.

Benefits of SuDS

  • Provide the potential to re-connect communities with water, providing benefits for comfort, health and well-being.
  • SuDS can provide new natural habitats, connecting nature and wildlife with urban environments
  • Keeping water on the surface allows any problems to be identified and managed quickly. Management of SuDS features can generally be cheaper, less time consuming and more straightforward than conventional drainage systems.
  • SuDS can be used for the natural treatment of surface water runoff

Examples of SuDS features

Soakaways

Soakaways
Soakaways

Below-surface features are designed to encourage water to soak into the ground. They are shallow depression areas which can be used for public open space for most of the time, only filling up during intense rainfall events when they can be used to provide storage

Green roof

Green roof
Green roof

A roof with plants growing on its surface allowing rainwater to be stored and treated. Green roofs can also promote evapotranspiration, allowing rainwater to be removed at the source. Green roofs can increase biodiversity and the aesthetic value of the site.

Permeable paving

Permeable paving
Permeable paving

Paved areas that allow water from the surface to soak into the ground through voids between solid parts of the pavement. Water can then soak straight into the soil beneath or can be stored underneath the paving and conveyed from the site in a controlled way. Permeable paving can also filter water as it flows through it, improving water quality.

Swales

Swales
Swales

Swales are shallow vegetated channels designed to convey or store surface water from the land. They can also be used to encourage water to soak into the ground. Vegetation within the swale can also filter water, improving water quality.

Attenuation Basins / Ponds

Attenuation basins/ ponds
Attenuation basins/ ponds

A pond or basin designed to store water during a storm and release it slowly in a controlled way. Attenuation basins can hold water permanently in a pond or wetland or can act as temporary storage features, remaining dry for most of the time but filling up during extreme rainfall events. Permanent storage features can promote biodiversity through creation of natural habitat such as reed beds. These reed beds also filter water, improving water quality.

We have created a number of SuDS case studies of sites across Cambridgeshire that can be viewed below: