Understanding flood vulnerability of buildings in US: A perspective through claims data

Abstract

The National Flood Insurance Program (NFIP) is the largest provider of flood insurance to residential homes and small businesses in the United States for the last 50 years. This study leverages 40 years of data from the NFIP claims dataset to understand which flood hazard and building features influence flood losses. While understanding the importance of building features such as type of occupancy, presence of basement, height or age etc. on flood resistance, the NFIP dataset also allowed us to explore additional characteristics such as the impact of NFIP guidelines and mitigation practices in newer buildings as well as regional variation due to code enforcement. Apart from building vulnerability, the claims also enable a look at which hazard and building features impact contents loss due to flooding. The occupancy of a building, type of flood hazard (surge, riverine, rainfall driven), flood zone and flood regulations compliance are the main drivers of flood vulnerability of both building and contents coverage. Additionally, this claims analysis also highlights the effectiveness of building code enforcement and the need to expand this mitigation and enforcement practices even outside the 100-year flood plain extent.