Sustainable drainage system statement validation guidance

From 6 April 2015, the Government expects all decisions on planning applications relating to major development to ensure that sustainable drainage systems for the management of run-off (also known as SUDS) are put in place, unless demonstrated to be inappropriate.

We have amended our local validation requirements to take into account this national policy.

When do I need to provide sustainable drainage system details?

The provision of sustainable drainage systems in major developments is a national planning policy requirement. In order to assess your proposal against national policy we need sufficient details to be provided before we validate your application.

A sustainable drainage system statement is required to accompany any planning application proposing:

  • Development of a building or buildings where the total floor space to be created is 1,000 square metres or more; or
  • Development of 10 or more houses; or
  • Outline applications for housing development on a site of 0.5 hectares or more; or
  • Other developments on a site of one hectare or more; or
  • Waste developments; or
  • The winning and working of minerals or the use of land for mineral-working deposits

What details do I need to provide?

National planning policy requires sustainable drainage systems to be provided in all major developments, unless they are shown to be inappropriate. Applications for major development must therefore include evidence to show:

  • The national standards for sustainable drainage systems can be met by the development; or
  • Sustainable drainage systems are demonstrably inappropriate for the development in question, having regard to the national standards for sustainable drainage.

What format should I submit my sustainable drainage system details in?

We recommend that the application presents sustainable drainage system details in a standalone statement which considers and addresses the Government's sustainable drainage technical standards one by one and in order. This approach will clearly show that the compliance of the proposal with national drainage standards has been fully considered.

The nature of the standards means a combination of plans, drawings, specifications and discussion will be required in your submission. Brief bullet points are usually a good way to present written information.

What will we take into account in assessing the measures proposed?

We will have regard to a number of factors in forming judgments on the suitability or otherwise of sustainable drainage system details and information, including:

  • Technical evidence of compliance that has been submitted with the application
  • Local and national policies
  • Local geographical, geological and hydrological factors which have been demonstrated
  • Costs which have been demonstrated

When we receive a major planning application we will consult the Lead Local Flood Authority (Cumbria County Council) with details and evidence provided by the applicant.

We will have regard to the views of the Lead Local Flood Authority in our decision making.

What if I believe sustainable drainage systems are inappropriate for my application?

The normal presumption is that sustainable drainage systems must be provided for major developments in line with national standards. Where an applicant feels that the provision of sustainable drainage systems would be inappropriate, the onus is on the application to evidence why sustainable drainage systems should not be provided, having regard to the national drainage standards.

Can sustainable drainage system requirements be dealt with by condition?

It is Government policy that all major developments should incorporate sustainable drainage systems unless they are demonstrated to be inappropriate, having regard to the national standards. Providing sustainable drainage systems can impact on a development's layout and design (for example if attenuation areas are required), and so should be considered from the earliest stages.

We can only impose planning conditions where there is a reasonable prospect that the requirements of the condition can be met. Therefore, even if we were to condition final details of a sustainable drainage scheme, an application would still need to contain enough information for us to be confident that the requirements of the condition and the national drainage standards could be met.