Sustainable Drainage Systems (SuDS) manage rainfall in a way that works with nature. Rather than moving water quickly through pipes, SuDS slow, store, filter and re-use rainwater close to where it falls.

Why SuDS Matter

Well-designed SuDS deliver benefits beyond drainage and flood management. They can:

• Reduce flood risk and improve climate resilience.

• Improve water quality by filtering pollutants.

• Support biodiversity and create wildlife habitats.

• Enhance public spaces and contribute to wellbeing.

• Increase urban greening, shade and cooling.

• Create attractive, distinctive and multifunctional places.

Integrating SuDS from the outset can help create an efficient drainage strategy while supporting long-term landscape quality and resilience.

Benefits for house builders and developers

Considering SuDS early can help developers create a more efficient and coordinated drainage strategy. Using surface-based features may reduce reliance on extensive underground pipework and large end-of-system attenuation, while avoiding the cost and duplicated effort that can arise when SuDS are added late in the design process.

When designed as part of the landscape, SuDS can also support attractive streets and open spaces, strengthen placemaking and contribute to the long-term value and marketability of a development. Early coordination between drainage, landscape, ecology and design teams helps identify the right measures for each part of a site and supports a clearer route through planning, construction and handover.

The Four Pillars of Sustainable Drainage

SuDS should be designed to deliver four connected outcomes:

Water quantity - Manage surface water runoff to reduce flood risk and erosion by slowing, storing, re-using and infiltrating rainwater.

Water quality - Filter pollutants before water returns to the environment.

Amenity - Create attractive, multifunctional spaces for residents and visitors.

Biodiversity - Provide habitats and strengthen ecological resilience across a development.

Four pillars of sustainable drainage

The four pillars show how SuDS manage water while supporting water quality, amenity and biodiversity.

A SuDS-first approach

Ebbsfleet promotes a SuDS-first, pipes-last approach. Sustainable drainage should be integrated into masterplanning, landscape design and engineering from the earliest stages of a project, rather than added after a conventional drainage system has been designed.

The most successful schemes use a series of linked features throughout the site. Managing rainfall close to where it falls reduces pressure on downstream infrastructure and makes better use of opportunities within buildings, plots, streets and open spaces.

The SuDS train

Soil and ground conditions 

Healthy, uncompacted soil is essential to the long-term performance of many SuDS features. Compaction caused by construction activity reduces the soil’s ability to absorb, store and filter water and can also restrict healthy planting. 

Soils should therefore be specified, protected and managed throughout design and construction. Where compaction cannot be avoided, suitable remediation may be needed so that SuDS can perform as intended. 

Uncompacted and compacted soil

Uncompacted soil contains pore spaces that allow water, air and roots to move through it; compaction restricts these pathways.

How EDC will use this guidance 

This guidance forms part of the wider Design for Ebbsfleet framework and supports the delivery of high-quality Sustainable Drainage Systems (SuDS) across Ebbsfleet Garden City.

The SuDS Selector supports EDC’s Sustainability Assessment System and provides a consistent methodology for applicants and planning officers when considering site-level SuDS provision. EDC will use it to inform pre-application discussions and assist with the assessment and scoring of SuDS within planning applications.

The SuDS Selector is non-statutory design guidance. It should be read alongside the Development Plan, relevant planning permissions and conditions, approved design codes and drainage strategies, and Lead Local Flood Authority requirements. It does not replace planning policy or statutory drainage requirements.

Applicants submitting Outline, Full or Reserved Matters applications should use this guidance to help identify appropriate SuDS features, develop a SuDS-first approach and demonstrate how surface water management has been integrated into the design of the development. Detailed specifications and technical information may be confirmed through planning conditions where appropriate.

Where proposals are brought forward under an existing outline permission, approved masterplan or design code, this guidance should be used as supporting guidance to help refine and enhance drainage proposals where appropriate. Existing approved principles will continue to apply unless superseded through a formal planning process.

Applicants are expected to comply with relevant planning policy and LLFA requirements and should engage with the LLFA at an early stage to agree the drainage approach, supporting information and verification requirements. This guidance complements those requirements and provides practical design advice on how SuDS can be successfully integrated at building, plot, street and neighbourhood scale.

A connected SuDS train manages rainfall in stages, from source control through conveyance and storage to controlled discharge.