Retrofitting sustainable drainage systems in UK schools: assessing the impacts and challenges

Sustainable Drainage Systems (SuDS) mimic natural processes to manage stormwater runoff close to its source, encouraging infiltration, attenuation, and passive treatment. SuDS can be used to mitigate flooding and provide increased climate resilience whilst simultaneously delivering amenity, biodiversity, and economic benefits to local communities. Retrofit of SuDS is a complex process requiring a detailed understanding of localised and catchment-wide drainage issues, and necessitates extensive buy-in from multiple stakeholders. Mutual understanding and recognition of the benefits of SuDS retrofit opportunities is critical to their implementation and success. This paper appraises the key benefits and challenges of SuDS retrofit within schools. A qualitative and quantitative assessment using case studies from over 50 completed SuDS retrofit projects within schools across the UK, for a variety of clients, has been conducted. Through the implementation of these solutions, hydraulic models have demonstrated a reduction in peak flow rates of up to 87%, providing flood alleviation to the schools' wider catchments and demonstration that SuDS can be used to provide reductions to Combined Sewer Overflow (CSO) spills. Barriers to implementation may be minimised by ensuring a client's aims are fully understood and achievable combined with a focus on stakeholder engagement throughout the decision-making process.