Why CIRIA's New SuDS Guidance is a Game-Changer for Developers

CIRIA has just released ground-breaking guidance that could transform how we approach drainage design in the UK. Their new publication, Enabling development: Getting SuDS right from the start (C823F), launched in September 2025, addresses a critical issue that's been costing developers time, money, and opportunities for years.

The message is clear: sustainable drainage systems (SuDS) must be considered from day one, not as an afterthought at the planning stage.

Take at the look at the video CIRIA produced to introduce the publication

 CIRIA Introduction

The Problem: Drainage as an Afterthought

Too often, drainage is only addressed when planning applications are being prepared. By this point, the masterplan is largely fixed, buildings are positioned, roads are laid out, and open spaces are defined. The opportunity to integrate SuDS effectively has already been lost.

This late-stage approach creates several problems:

• Increased flood risk that could have been mitigated

• Higher long-term costs for retrofitting solutions

• Missed opportunities for biodiversity and water quality improvements

• Reduced site value and saleability

• Delays in the approval process

Emma Cecil, Senior Civil Engineer at Arup and one of the guide's authors, explains: "We have written this guide as targeted, simple support for those involved in the very early stages of site progression to demonstrate how early consideration of sustainable drainage can maximise benefits and mitigate risks."

The Solution: Early Integration of SuDS

CIRIA's new guidance provides a practical, checklist-style resource designed specifically for stakeholders at the earliest stages of development: land acquisition and masterplanning. It's targeted at developers, planners, landowners, Lead Local Flood Authorities, and consultants working on residential, commercial, industrial, and infrastructure projects across both greenfield and brownfield sites.

The guidance demonstrates how early SuDS planning delivers tangible benefits:

Financial Benefits

• Reduced long-term costs: Integrating SuDS from the start is far more cost-effective than retrofitting solutions later

• Optimised developable land: Proper planning maximises the usable area of your site

• Aligned costs with land acquisition: Understanding drainage requirements early helps with accurate site valuation

• Improved return on investment: Enhanced environmental credentials boost property values

Planning and Approval Benefits

• Accelerated approval process: Demonstrating early consideration of SuDS can smooth the path through planning

• Greater community support: Well-designed SuDS create attractive, sustainable places that residents value

• Compliance confidence: Meeting evolving planning requirements becomes straightforward

Environmental and Social Benefits

• Reduced flood risk: Proper surface water management protects properties and infrastructure

• Improved water quality: SuDS naturally filter pollutants before water enters watercourses

• Enhanced biodiversity: Green infrastructure creates habitats for wildlife

• Climate resilience: Future-proofing developments against increasing rainfall and extreme weather

• Improved place-making: SuDS features like rain gardens and swales enhance the character and amenity of developments

From Constraint to Opportunity

Adrien Baudrimont, Senior Research Manager at CIRIA and project lead, emphasises the win-win nature of this approach: "Early consideration of SuDS represents a win-win for both land agents and masterplanners, ensuring better outcomes for new developments via sustainable drainage. Our aim is to make it easier to capture the multiple benefits of SuDS, while also unlocking the added value they can bring to a development."

The guidance reframes drainage from a technical constraint to a strategic opportunity. When considered early, SuDS can:

• Shape the overall site layout in beneficial ways

• Create attractive landscape features that enhance property values

• Provide multifunctional spaces for recreation and biodiversity

• Demonstrate environmental leadership that appeals to buyers

• Build resilience against climate change impacts

Practical Resources for Decision-Makers

CIRIA hasn't just produced another technical manual. The guidance is deliberately structured to be accessible and actionable for busy decision-makers:

• Straightforward principles: Clear, practical advice without unnecessary jargon

• Checklist-style format: Easy-to-follow guidance for each stage of early development

• Accompanying animation: A visual resource that brings the concepts to life

• Stakeholder-tested: Developed with input from a steering group of end-users to maximise usefulness

The guidance is available as a free download from CIRIA's website, making it accessible to all stakeholders involved in development.

The Bigger Picture: Climate Change and Planning Policy

This guidance arrives at a critical time. With increasing flood risk, climate change impacts, and evolving planning requirements, the pressure on developers to demonstrate sustainable surface water management has never been greater.

Recent extreme weather events have highlighted the vulnerability of developments that don't adequately manage surface water. Lead Local Flood Authorities are increasingly scrutinising drainage proposals, and planning policies across the UK are strengthening requirements for SuDS.

By getting SuDS right from the start, developers can stay ahead of these trends and create developments that are truly fit for the future.

What This Means for Your Next Project

If you're involved in land acquisition, masterplanning, or early-stage development, this guidance offers a clear roadmap for success:

1. Assess surface water management at land acquisition stage: Understand opportunities and constraints before committing to a site

2. Integrate SuDS into masterplanning: Work with drainage specialists early to shape the site layout

3. Engage with Lead Local Flood Authorities: Build relationships and understand requirements from the outset

4. Consider multifunctional benefits: Design SuDS that provide amenity, biodiversity, and drainage functions

5. Communicate the value: Use SuDS as a selling point for environmental credentials and resilience

Emma Cecil's advice is worth heeding: "I hope that a quick flick through can save your site from many headaches in the future and help you reap the multifunctional benefits that SuDS can offer."

Taking Action

The guidance represents a significant step forward in how the industry approaches sustainable drainage. By providing clear, practical advice for the earliest stages of development, CIRIA has created a resource that can genuinely transform outcomes.

For developers, the message is simple: drainage isn't just a technical requirement to be dealt with at planning stage. It's a strategic consideration that can unlock site value, reduce risk, and create better places.

The earlier you consider SuDS, the more seamlessly they can be incorporated into your site design, unlocking benefits at scale and with minimal disruption. In an era of climate change and increasing scrutiny of surface water management, getting SuDS right from the start isn't just good practice. It's essential for successful development.

Resources

The guidance document Enabling development: Getting SuDS right from the start (C823F) is available as a free download from the CIRIA website. The accompanying animation can be viewed on the CIRIA News YouTube channel here 

For specialist drainage design advice on your development projects, early engagement with qualified drainage designers can help you implement the principles outlined in this guidance and maximise the benefits for your site.