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Sustainable drainage systems

Sustainable drainage systems (SuDS) can reduce the impact of development on the environment by mimicking the natural process of surface water management.

East Sussex County Council encourages all developments to use SuDS to manage flood risk and improve water quality, the local environment and wildlife habitats.

The County Council, in partnership with other South East Lead Local Flood Authorities (LLFAs) has produced a guide that sets out the framework for integrating SuDS in development layouts.

Read the guide below:

More information on SuDS is available from the website of Susdrain.

SuDS and planning policy

The Secretary of State for Communities and Local Government delivered a written Ministerial Statement - UK Parliament on the implementation of SuDS in Parliament on 18 December 2014. The statement made changes to the National Planning Policy Framework (NPPF) which in turn made SuDS a material consideration while determining planning applications for major development. These changes came into effect on 6 April 2015.

Alongside the changes to NPPF the Development Management Procedure Order was amended, making East Sussex County Council as LLFA (South East Lead Local Flood Authority) a statutory consultee to the planning process on the management of surface water, starting from 15 April 2015.

Consequently, developers need to provide SuDS on major development where appropriate, while paying due regard to the following:

Pre-application advice


East Sussex County Council as the LLFA is working in partnership with the Pevensey and Cuckmere Water Level Management Board (PCWLMB), to advise planning authorities on the impact of development on local flood risk within the Board’s catchment. Developers need to liaise with both organisations for sites within the Board’s catchment. The Board’s Flood and Water Officer is contactable through the Council by emailing our Flood Risk Management Team.

The County Council encourages developers to hold pre-application discussions to reduce delays in the determination of a planning application. However, this advice is chargeable and our tariff along with an application form for pre-application advice can be accessed below.

We also provide a checking service for data which may be required as part of a Flood Risk Assessment or the development of a drainage strategy. This service is also chargeable and details are set out in the tariff.

The County Council has developed a guidance document and tools which developers are advised to refer to during the development of surface water management strategies for the website:

Surface water drainage checklist

The surface water drainage checklists list all the information the Council expects to be included in a surface water drainage strategy supporting a planning application.

More pre-application information will be published soon.

LLFA policy on deep bored soakaways

Due to their nature deep bored soakaways increase the risk of groundwater contamination as there is potential for a direct discharge to groundwater. Therefore, we recommend that they are used as a last resort where the ground conditions and the groundwater levels are known. The County Council requires that the following criteria are met when deep bored soakaways are proposed:

  • Investigations showing that there are no other alternative surface water destinations
  • The depth of the system should be no deeper than what is required for soakage – which requires understanding of the underlying geological layers
  • Adequate pollution prevention measures must be provided upstream of the soakaway – utilising at least two water treatment stages using SuDS measures
  • A sufficient unsaturated zone must be provided below the base of the structure – recommend 10m between the base of the structure and recorded groundwater level

Contact us

For more information or a pre-application discussion email the Flood Risk Management team

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