Sustainable drainage systems, often referred to as SuDS, is a drainage solution designed to control surface run off close to where it falls and mimic natural drainage as closely as possible. Sustainable drainage systems provide opportunities to reduce the causes and impacts of flooding; remove pollutants from urban run-off at source; and, combine water management with green space with benefits for amenity, recreation and wildlife.
Planning application requirements and general guidance
On 19 June 2025, the government published new non-statutory national standards for SuDS (external link).
Surrey County Council is the Lead Local Flood Authority and is consulted on all major developments (ten or more dwellings or 1,000 square metres or more). Since 6 October 2025 they assess all planning application consultations against the new national standards.
To ensure that the necessary SuDS evidence is provided with a planning application it is advisable that you engage with them. The Surrey County Council website (external link) provides details of a chargeable pre-application advice service. It also provides useful SuDS design guidance for major and non-major development proposals.