The Government Says

Review of property level flood protection measures

Review of property level flood protection measures
Local copy of Post-Installation_Effectiveness_of_Property_Level_Flood_Protection__final_report.pdf

https://www.gov.uk/flood-and-coastal-erosion-risk-management-research-reports/review-of-property-level-flood-protection-measures

seen at 11:16, 23 February in Search.