Sustainable Drainage Systems (SuDS)
Following the significant flooding in 2007, the independent Pitt Review identified that Sustainable Drainage Systems (SuDS) offer an effective means of reducing the risk of surface water flooding, particularly ‘flash flooding’ caused when rainfall rapidly enters the sewerage system, leading to overloading and surface water backup.
The review also highlighted that traditional drainage approaches often treat surface water as a waste product, rather than managing it as a natural resource. In contrast, SuDS are designed to manage surface water in a more sustainable and environmentally responsible way.
What are SuDS?
SuDS are drainage solutions that aim to manage the quantity, quality, and flow pathways of surface water, especially where these are affected or altered by new developments. They work by replicating natural drainage processes such as infiltration, attenuation, filtration, and evapotranspiration.
The CIRIA SuDS Manual (C753) identifies four key design considerations, often referred to as the four pillars of SuDS:
- Water Quantity – focuses on controlling the volume and rate of surface water runoff to reduce flood risk
- Water Quality – manages pollutants in surface water to reduce environmental harm and protect water bodies
- Amenity – enhances the design of developments by creating attractive, accessible, and usable spaces for people, integrating natural features where possible
- Biodiversity – supports the creation of habitats and ecosystems that encourage wildlife and enhance ecological value through site-specific SuDS features.
This has further been expanded under the National Standards for SuDS which was released by DEFRA on 17 June 2025 and places requirements on the standards that should be adhered to within SuDS developments. By incorporating SuDS into development proposals, we can reduce the negative impacts of urbanisation on the natural water cycle, promote flood resilience, and deliver multi-functional spaces that benefit both people and the environment.
Policy and Planning Context
Section 14 of the National Planning Policy Framework (NPPF) states that developments which affect surface water drainage should incorporate SuDS to control runoff rates and volumes. These systems should be proportionate to the scale and nature of the development and provide multiple benefits including improvements in water quality, biodiversity, and public amenity where possible.
Local Planning Authorities (LPAs), when determining planning applications, must consider flood risk and ensure that developments do not increase flood risk to people or property. Reducing the residual risk of flooding contributes to better public safety and environmental resilience.
In line with the Flood and Water Management Act 2010, the Lead Local Flood Authority (LLFA) is a statutory consultee on relevant major planning applications. Developers are expected to consult the LLFA and consider their recommendations when designing drainage strategies.
For further information on SuDS and how they should be implemented in North Lincolnshire:
- Refer to our SuDS guidance document, Surface Water Drainage Checklist and Ordinary watercourse consent application form, which together offers practical advice to developers and designers on incorporating sustainable drainage systems appropriate to the site’s location and scale
- Refer to the National Standards for SuDS requirements document.
- Visit our planning policy page or consult the National Planning Practice Guidance website for more details.