Surface water and sustainable drainage systems (SuDS) planning

Cambridgeshire County Council is a Lead Local Flood Authority (LLFA) and as such is a statutory consultee to the planning process for surface water on all major developments. The consultation requirement and description of major development is detailed within the Town and Country Planning (Development Management Procedure Order). This applies to all new major planning applications.

New National Planning Practice Guidance and non statutory technical standards for sustainable drainage systems will aid our responses to consultations. 

Flood and Water Supplementary Planning Document

Cambridgeshire County Council, in its capacity as LLFA endorsed the Cambridgeshire Flood & Water Supplementary Planning Document (SPD) on 14 July 2016. The SPD has been adopted by the county’s five Local Planning Authorities (LPAs).

The SPD was prepared in conjunction with the LPAs and other relevant stakeholders including the Environment Agency, water companies and Internal Drainage Boards, to support the implementation of flood risk and water related policies in the Local Plans. In its role as a statutory consultee for surface water drainage, the LLFA will follow the guidance in this SPD. 

Advice to developers

In addition to the SPD, we have published more specific guidance on the preparation of surface water drainage strategies. This provides information on the level of detail we require depending on the type of planning application. This guidance document should be used by all developers and their consultants.

SWGFD FINAL - November 2019
Size: 1.49MBFile format: pdf

Pre-application advice

In order to provide additional support to developers and their consultants we offer a pre-application advice service for all scales of development. We offer several forms of advice including:

  • Free telephone advice service - free 15 minute phone call with a flood risk officer to discuss surface water drainage proposals. This is suited for all stages of application. Email FR.Planning@cambridgeshire.gov.uk to book your slot.
  • Written advice only - most suited to developers who have already advanced quite far with their drainage strategies and are looking for a review of their proposals.
  • Telecom meeting with LLFA Officer and written advice - most suited to developers who have ideas about how to approach their drainage strategy but who would like to discuss the detail with officers by telephone or video conference. Each meeting is followed up with a written summary of the meeting. 
  • Meeting with LLFA Officer and written advice – most suited to developers who have ideas about how to approach their drainage strategy but who would like to discuss the detail with officers. Each meeting is followed up with a written summary of the meeting.

The pre-application advice service is structure to provide ‘in principle’ feedback on proposals as well as more detailed discussions and negotiations on a scheme prior to formal submission of a planning application.

If you wish to take up our pre-application service please complete the online application form below (where full details of the charges are provided). For the free telephone advice service, please email FR.Planning@cambridgeshire.gov.uk to book your time slot, using the email subject header 'free telephone advice service'.

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 in order to reduce flood risk caused by development. SuDS generally replace traditional underground, piped drainage systems. The aim of SuDS is to keep water on the surface as much as possible. They can integrated into both rural and urban developments.

Benefits of SuDS

  • Provides the potential to re-connect societies with water, providing benefits for amenity, 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 straight-forwards than conventional drainage systems.

Examples of SuDS features

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

Case Study Eddington
Case study
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Case Study Fen Drayton
Case Study
Size: 679KBFile format: pdf
CLAY FARM CASE STUDY
Case study
Size: 661KBFile format: pdf
Loves Farm Case Study
Case Study
Size: 582KBFile format: pdf