Paragraph 18 Flood risk and surface water drainageI1

No component of the authorised development on the main site (excluding archaeological investigation, ecological mitigation works and geotechnical or ground contamination investigation) must commence until a surface water drainage scheme for that component based on sustainable drainage principles has been submitted to and approved in writing by the lead local flood authority. The scheme must be in accordance with the sustainable drainage statement and must be informed by additional infiltration testing in accordance with BRE standard 365 “Soakaway design”, the extent of which is to be approved in advance by the lead local flood authority, the aim of which is to identify the maximum extent of reliance upon infiltration in accordance with the drainage hierarchy set out in the sustainable drainage strategy.

The surface water drainage scheme must be implemented in accordance with the details approved by the lead local flood authority or in accordance with any variations to those details agreed in writing by the lead local flood authority.