Sustainable Drainage Systems (SuDS)

DCC are a statutory consultee for all major planning applications in Devon.  To help improve our service we are now offering pre-application advice to help improve the outcome for all parties.  Please see below for further information including charging.  We have also introduced a Ground Water Monitoring Policy to highlight the need for monitoring when infiltration devices are proposed.

Allowance for Urban Creep

As part of our ongoing review of standards and to adhere to current best practice, we now expect 10% urban creep to be included in surface water drainage calculations submitted in support of any new planning application after the 1st December 2020.

We have reviewed the latest update to the EA Flood Risk Assessments: Climate Change Allowances dated July 2020 and for our area 40% allowance for rainfall intensity is still applicable and should be incorporated within the surface water drainage calculations.

FEH Rainfall

As of 1st June 2020, any new planning application should use FEH rainfall data within the design of the surface water management strategy.  Any applications submitted prior to this or applications at a later stage of planning can still use other methods.

SuDS Adoption

The Sewerage Sector Guidance was approved by Ofwat, under its Code for Adoption Agreements, and contains new rules on surface water sewers. Since 1st April 2020, South West Water (SWW) have the ability to adopt certain sustainable drainage systems provided they comply with the criteria outlined in the new Design & Construction Guidance.   The decision whether or not to adopt a sustainable drainage feature will lie with SWW.  We recommend early consultation with both SWW and ourselves where an application proposes the adoption of sustainable drainage systems by SWW.

Sustainable Drainage Systems Workshop

On Friday 11th October 2019 we hosted a free informative workshop to provide an update on our SuDS role, at the Kenn Centre.

Public Representations

Devon County Council, as the Lead Local Flood Authority for its area, are a statutory consultee to the Local Planning Authority (LPA) regarding the provision of surface water management for new ‘major’ development applications. These are defined within Part 1(2) of The Town and Country Planning (Development Management Procedure) (England) Order 2015. We are resourced only to provide this service and as such are unable to respond directly to all public representations that we receive. Any representations that you wish to make should be sent directly to the relevant planning authority, which are listed below, as they are the determining body for any planning application.

Within our statutory consultee role we ensure that we consider all information available to us before providing an unbiased and properly informed decision as to the appropriateness of the surface water management proposed for any new development. Any information sent direct to us will be taken into account when providing our response, however it should be noted that it is not always possible to provide the sender of such information with any direct acknowledgement or specific comment.

The Local Planning Authorities in Devon are – East Devon District Council, Exeter City Council, Teignbridge District Council, South Hams District Council, West Devon Borough Council, Mid Devon District Council, Torridge District Council, North Devon Council, Dartmoor National Park, Exmoor National Park and Devon County Council, (as the planning authority for minerals and waste development and development undertaken by DCC)

SuDS Principles

Approaches to managing surface water which take account of water quantity, water quality, public amenity and biodiversity issues are collectively referred to as Sustainable Drainage Systems (SuDS).

Conventional drainage systems employ underground pipe networks which prevent localised flooding by conveying water away as quickly as possible; they are only effective at managing water quantity (flows and volumes). SuDS are able to manage surface water flows and volumes in open features on the ground surface, whilst also providing benefits to water quality, public amenity and biodiversity. These systems are more sustainable than conventional drainage methods because they:

  • Manage runoff volumes and flow rates, reducing the Picture of a Swaleimpact of urbanisation on flooding;
  • Protect or enhance water quality;
  • Are sympathetic to the environmental setting and the needs of the local community;
  • Provide a habitat for wildlife in urban watercourses.

More information regarding SuDS can be found on the Susdrain website.

Legislation Changes and Implications

Under Schedule 3 of the Flood and Water management Act (2010), Lead Local Flood Authorities (LLFAs) were to be required to establish a SuDS Approval Body (SAB) which would have required Devon County Council (DCC) to approve, adopt and maintain SuDS features in new developments. However, in December 2014, the Government announced that Schedule 3 would not be enacted because SuDS would be dealt with by strengthening existing planning policy instead. This change, which took effect on 6th April 2015, requires Local Planning Authorities to make the final decision about the suitability of the SuDS provision on new developments and whether it is proportionate to the level of flood risk affecting the site.

Whilst DCC will no longer be required to establish a SAB, we are now a statutory consultee for major developments which have surface water implications. This new responsibility requires us to provide comments in relation to surface water drainage aspects of planning applications, usually within 21 days.

Last updated: June 2020