Sustainable drainage systems: the future of urban resilience

Climate change and the resulting increase in urban flooding currently pose a significant challenge to the UK’s sewer infrastructure. With the UK’s drainage structure straining under the pressures of ageing and intensified rainfall, the urgency for innovative and effective drainage solutions has never been greater.

Sustainable drainage systems (SuDS) are an effective solution to prevent urban flooding;  however, they are not currently widely adopted. To unlock the potential of SuDS and ensure a flood-resilient future, architects and housebuilders must understand the key considerations regarding the environmental impact of developments, the barriers preventing adoption, and the legislative changes set to make these systems a mandatory part of new residential projects.

What are sustainable drainage systems?

Put simply, sustainable drainage systems (SuDS) offer a practical and eco-friendly solution to manage rainfall and mitigate flood risks. They work by lessening the amount of rainwater that pours into sewers when it falls by holding onto the water and letting it soak into the earth or releasing it gradually – instead of just funnelling rainwater into sewers and rivers like traditional drainage does. They also clean the water naturally, removing contaminants.

What are the benefits of SuDS?

The benefits of SuDS include mitigating urban flooding by reducing the runoff entering sewer systems during heavy rainfall, which improves water quality by naturally filtering out pollutants. Moreover, SuDS not only ease the burden on our sewer infrastructure but also help to boost city greenery and wildlife by integrating features like green roofs, rain gardens, and porous paths. These elements not only have aesthetic and environmental benefits but also help to cool cities down, offsetting the heat island effect where built-up areas are significantly warmer than their surroundings.

So, why are SuDS not being widely adopted?

Even though SuDS have been available for decades – and is a proven approach to mitigating flood risks by managing rainwater at its source – their adoption within new build developments has been surprisingly slow. To bolster the uptake of SuDS in new construction projects, Ofwat’s Code for Adoption guidance was introduced in 2021, which questions the barriers to widespread adoption.

One significant barrier to broaden SuDS implementation lies in the housebuilding community’s apprehensions and knowledge gap. These range from concerns over the complexity of SuDS installation to a lack of definitive clarity surrounding the definition and requirements of their integration into projects. Such hurdles are further compounded by a notable gap in the availability of information and resources aimed at explaining SuDS for builders and developers.

However, it looks as though uptake could be on the rise due to the forthcoming enforcement of Schedule 3 of the Flood and Water Management Act 2010 in England, which mandates the incorporation of SuDS in all new residential developments larger than 100m². This legislative shift, already in effect in Wales since 2019, signals an urgent need for the housebuilding sector to adapt swiftly. Yet, the introduction of this mandate also highlights the importance of recognising the unique characteristics of each development site to ensure the successful implementation of SuDS.

How can we overcome these barriers?

Tailoring sustainable drainage systems to suit specific site conditions – including soil type, terrain, and existing infrastructure – is crucial for maximising their effectiveness. Integrating sustainable urban drainage system planning and design early in development projects not only helps meet regulatory requirements but also boosts the resilience and sustainability of urban areas in the face of escalating flood risks.

Leading players in the drainage industry are ready to assist housebuilders in navigating the complexities of implementing SuDS. By providing educational programmes, tailored products, and expert advice, these leaders are dedicated to making the shift to sustainable drainage practices smoother for developers. Effective collaboration among all stakeholders, such as local authorities, environmental agencies, and drainage experts, is vital for successfully deploying SuDS.

Adopting sustainable drainage represents not just a compliance measure but a strategic opportunity for the UK’s housebuilding sector. By adopting SuDS, developers’ role in reshaping urban environments into resilient, sustainable and appealing living areas is crucial. However, those within the drainage industry must lead the way, providing the necessary expertise, innovative solutions, and support to ensure sustainable urban drainage becomes a reality for developers – and ultimately for residents – nationwide.

To learn more about sustainable drainage solutions, visit our dedicated page or get in touch.