NPPF F8: Sustainable drainage systems and watercourses

F8: Sustainable drainage systems and watercourses 1. Development proposals which could affect drainage on or around the development site should incorporate sustainable drainage systems to control flow rates and reduce volumes of runoff, in ways which are proportionate to the nature and scale of the proposal. The systems employed should provide multifunctional benefits where possible, facilitating improvements in water quality, biodiversity and amenity. 2. Sustainable Drainage Systems should: a. Be designed in accordance with the National Standards for Sustainable Drainage Systems57; For the purpose of policy F2, when the exception test is being applied at the plan-making stage, it should be informed instead by an up-to-date strategic flood risk assessment. National Standards for Sustainable Drainage Systems published in: National standards for sustainable drainage systems (SuDS) - GOV.UK. 87 b. Have maintenance arrangements in place to ensure an acceptable standard of operation for the anticipated lifetime of the development; and c. In the case of proposals for major development, take account of advice from the Lead Local Flood Authority. 3. Development proposals should not enclose existing watercourses where this is not already the case, unless there are compelling reasons to do so; and should where possible remove existing culverts and renaturalise existing river channels, unless to do so would increase flood risk, result in other environmental harm or cause harm to heritage assets.