Sustainable urban drainage systems (SUDS) are structures designed to resourcefully manage the drainage of surface water within the urban environment. With sustainable urban drainage systems in addition to traditional drainage systems, water is drained directly and quickly into underground through piped drainage.

Over the years, as population increase, particularly in urban areas, and ‘soft’, permeable site has been replaced with hard surfaces, surface water runoff reaches traditional piped drainage sooner and in greater measures. This has been exacerbated by the loss of rural features which may once have slowed the passage of surface water, being replaced with large, intensively farmed fields that rapidly release surface water into piped drainage or watercourses that make their way into urban areas.

The result has been higher peak flows leading to serious flooding of urban areas, pollution, damage to habitat and contamination of groundwater sources.

Sustainable urban drainage systems aim to mimic ‘natural’ drainage by adopting techniques to house surface water runoff locally, through collection, storage, and cleaning before allowing it to be released slowly into the environment.

According to CIRIA, ‘SUDS techniques seek to capture, use, delay or absorb rainwater, instead of reject it as a nuisance or problem. Sustainable drainage delivers multiple benefits. further as delivering top quality drainage whilst supporting areas to cope better with severe rainfall, SuDS also can improve the standard of life in developments and concrete spaces by making them more vibrant, visually attractive, sustainable, and resilient to alter by improving urban air quality, regulating building temperatures, reducing noise and delivering recreation and education opportunities.’

The benefits of sustainable urban drainage systems

Sustainable urban drainage systems are likely to become even more important as population increases, as the impact of global climate change is felt. Here are a few benefits of SuDS

  • Reducing flooding.
  • Reducing the demand on existing drainage systems (potentially making a development viable in a district where it’d otherwise not be viable).
  • Enhancing water quality.
  • Reducing pollution.
  • Providing habitats for wildlife.
  • Providing local amenity.
  • Recharging groundwater and watercourses leading to a reduced risk of drought. 

Sustainable urban drainage systems should be considered during the positioning selection process. Different management strategies could also be required for various parts of a site, and flows from roofs should even be considered.