Understanding the NPPF Updates on SuDS and Flood Risk

In December 2024, the UK Government introduced significant updates to the National Planning Policy Framework (NPPF). These changes reshape the approach to Sustainable Drainage Systems (SuDS) and flood risk management, providing clearer expectations for developments of all scales. Here, we unpack the key updates and their implications for planners, developers, and local authorities.

Key Updates to the NPPF: Paragraph 182

The updated NPPF now places an enhanced focus on integrating SuDS into planning applications, emphasizing their importance not just for major developments but across a wider range of projects.

Previous Guidance (2023)

• Paragraph 175: SuDS were required only for major developments unless clear evidence indicated otherwise. Key elements included:

  • Incorporating advice from Lead Local Flood Authorities (LLFAs).

  • Meeting operational standards.

  • Ensuring maintenance agreements for the lifetime of the development.

  • Where feasible, providing multifunctional benefits such as biodiversity and amenity enhancements.

    
    

Current Guidance (2024)

• Paragraph 182: The updated policy widens SuDS application and explicitly includes smaller-scale developments where appropriate. It requires:

  • Managing runoff rates and reducing volumes proportionate to the proposal's scale and nature.

  • Delivering multifunctional benefits such as improved water quality, biodiversity, and public amenity.

  • Incorporating advice from LLFAs, operational standards, and long-term maintenance arrangements.

This shift encourages a broader and more creative approach to flood risk management in development planning.

The Expanding Role of SuDS

The new guidance reflects a growing emphasis on sustainable water management at all levels of development, with SuDS being integral to both urban and rural planning. By designing developments with sustainable drainage in mind, planners can address multiple challenges, including flood risk, water quality, and urban greening

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Implications for Local Authorities and Developers

A Shift in Focus

The updates signal that SuDS are no longer exclusive to large-scale projects. Developers are now expected to demonstrate how sustainable drainage has been incorporated even in smaller schemes, particularly in areas prone to surface water flooding. This reflects a move toward climate resilience at all scales.

Integration with Local Policies

Local Planning Authorities (LPAs) are increasingly embedding SuDS requirements into their development frameworks. For example:

• Croydon Council’s Policy DM25 emphasizes:

  • Managing surface runoff at its source.

  • Achieving better-than-greenfield runoff rates.

  • Multifunctional integration of drainage into public spaces.

  • Enhancing biodiversity and water quality.

• Arun District Council’s Policy W DM3 highlights:

  • Early incorporation of SuDS into the design process.

  • Capturing and treating surface water effectively while complementing the site’s character.

Understanding these specific local requirements is essential for developers to navigate the planning process effectively.

Practical Benefits of SuDS

Flood Risk Mitigation

By slowing and storing surface water runoff, SuDS reduce the risk of localized flooding. Features such as swales, permeable paving, and retention basins manage water naturally and help prevent overwhelmed sewer systems.

Enhanced Biodiversity and Public Spaces

Integrating SuDS into developments can create green, biodiverse areas that serve as public amenities. For example, a well-designed SuDS network might include wetlands or green roofs, offering ecological and recreational benefits.

Future-Proofing Developments

The NPPF revisions align with climate change projections, ensuring that developments remain resilient to increased rainfall intensity and rising flood risks over time.

Adapting to the New Landscape

To meet the revised requirements, developers should:

1. Engage Early with Local Authorities: Proactively consult LLFAs and LPAs to understand specific expectations and avoid delays.

2. Incorporate SuDS at the Design Stage: Ensuring sustainable drainage features are central to site planning will streamline the approval process.

3. Consider Long-Term Maintenance: Establish clear maintenance agreements to ensure SuDS functionality throughout the development’s lifespan.

   
   

Conclusion

The updated NPPF and associated SuDS policies mark a significant step forward in sustainable flood risk management. By encouraging the use of SuDS in all types of developments, these changes not only address immediate challenges like flooding but also contribute to long-term environmental and community benefits. For developers and planners, embracing these principles is not just a compliance issue—it’s an opportunity to create resilient, sustainable places to live and work.