Sustainable Drainage System (SuDS)

Given the recent severe flooding in parts of Europe and forecasts predicting more frequent extreme weather events, the planning and design of new interchanges and rebuilding of existing interchanges should include careful drainage planning.

Sustainable drainage (SuDS) provides a set of standards for providing a sustainable drainage system or features to follow under the following categories: surface runoff, off-site flood risks, peak flow control, volume control, flood risk within development, water quality, structural integrity, designing for economic sustainability, construction, maintenance and operation. The standards set out the requirements in a clear way so that flooding risks and water pollution can be minimised. Furthermore, careful drainage planning is a statutory requirement of all planning applications in the UK with the exception of Highways and Network Rail. Moreover one key aspect is the taking of new land out of the established flood plain, thus reducing its capacity. This either has to be avoided to keep the existing capacity or else replacement flood capacity has to be provided elsewhere that fulfils the same role.

These standards and categories aim to:

  • manage runoff volumes and flow rates, reducing the impact of urbanisation on flooding
  • preserve or enhance water quality
  • fit in with the environmental setting and the needs of the local community
  • provide a habitat for wildlife in urban watercourses
  • encourage natural groundwater recharge (where appropriate)

All measures ensure that the running of interchanges is problem-free. Thus there are solutions for possible problems caused by flooding

NODES strategic objectiveContribution
Enhance accessibility and integration 0
Enhance intermodality 0
Enhance liveability ++
Increase safety and security conditions 0
Increase economic viability and costs efficiency ++
Stimulate local economy 0
Increase environmental efficiency ++
Increase energy efficiency 0

Good practice

Cambridge Design Guide:

Essex Design Guide:

The rail station in Dülmen implements measures for flood prevention:

Application in NODES sites

Reading Station redevelopment has incorporated a number of sustainable drainage features:

  • the paving at the interchange sites adjacent to the station has been laid in sand to improve on the areas made of tarmac (immediate soaking away of rainfall)
  • a subway should have been made available for cycling and pedestrians, but it was impossible to provide the required headroom whilst at the same time ensuring that the design would not create a sump for water to collect
  • drainage was completely updated to provide much better resilience to potential flooding incidents

an artificial lake has been established in order to act as a sump

Potential interchange performance improvement

The tool allows easy assessment of sustainable drainage systems and prompts the use of various measures to improve drainage and the environment. By minimising flood and pollution risks, the interchanges should mostly or always remain functional and easy to use for both operators and passengers during severe weather conditions.

The SuDs checklist enables developers and stakeholders to assess and evaluate the measures necessary and desirable to allow the interchange to function during severe weather conditions when travel disruptions need to be kept to a minimum.

SuDs is designed to both manage the flood and pollution risks resulting from urban runoff and to contribute wherever possible to environmental enhancement and place making. With this in mind, the multi-functionality and multiple benefits of SuDS should always be considered.


  • low cost because of the self-assessment checklist
  • staff time and supporting information from architects/engineers/planners at design stage to administer an audit
  • may instigate wider consideration of SuDs measures to be designed and built into scheme
  • costs could be split between stakeholders


The key principles and benefits of SuDS are listed here:

More general information about SuDS:


Detailed information on how SuDS is being applied around the UK:

Sustainable drainage systems (SuDs) are designed to manage stormwater locally (as close to its source as possible), to mimic natural drainage and encourage its infiltration, attenuation and passive treatment. – See more at: