As appeared in the Winter edition of the Royal Town Planning Institute plaNIt newsletter.
Water does not recognise the boundaries between local authority areas, development sites, highways, sewer networks and river catchments. Yet our decisions about managing it often follow those divisions and vary across all four nations within the UK. As development and climate pressures increase, sustainable drainage systems (SuDS) provide an opportunity to connect those decisions and deliver benefits beyond individual site boundaries.
Wales and Northern Ireland offer complementary lessons about how to achieve this. One through a statutory framework, the other through an integrated approach to drainage and wastewater planning.
In Wales, statutory SuDS requirements have been operating since 2019 through local authority SuDS Approving Bodies (SABs). The framework requires qualifying developments to obtain drainage approval against statutory standards, separately from planning permission, and provides for adoption and maintenance, subject to conditions and exemptions.
The value of this approach is the clear responsibility it establishes and the emphasis it places on blue-green infrastructure. Drainage needs a clear route through design, approval and long-term management. For developers, this is encouraging earlier conversations and more holistic thinking towards layouts and land allocation, reducing late design changes. For communities, it provides a more nature-first approach to drainage and leaves a greener legacy.
In Northern Ireland, the multi-agency Stormwater Management Group has brought DfI and environmental colleagues together to explore practical arrangements for approving and maintaining nature-based SuDS, including through pilot developments. Alongside this work, the Living With Water programme illustrates the value of integrated planning across the wider water system. It brings together organisations responsible for drainage, wastewater, flood risk and the environment, combining conventional infrastructure investment with blue-green measures to address shared catchment pressures.
In practice, managing water at the asset means we can often miss opportunities to manage rainfall at source or along its route. Looking upstream at a park, public space or development could help hold back rainfall, reducing pressure on downstream drainage. Northern Ireland’s approach to catchment thinking is creating huge opportunities for environmental and amenity enhancements and importantly, identifying opportunities for organisations to look beyond their individual responsibilities.
Wales’ experience raises a question about proportionality. Statutory approval provides a clear framework, but how do we ensure that technical requirements, approval processes and maintenance contributions remain proportionate to the scale and risk of a development? Greater certainty over costs and decisions would help developers plan viable schemes while retaining the safeguards communities need.
Catchment planning offers an opportunity to consider where investment would achieve most and who should contribute. Managing rainfall in one location may reduce pressure on sewers, protect roads and benefit homes elsewhere. Where several organisations benefit, investment should reflect those shared benefits, with clear responsibilities for delivery and maintenance.
For further discussion on how to make SuDS work through clear responsibilities and integrated water management, please reach out to Robert Bramwell-Carr, our Director and Head of Flood Risk and Drainage.