Federally-Overlooked Flood Risk Inequities in the Conterminous United States

Keywords: Flooding, Environmental Justice
Abstract Type: Paper Abstract

Abstract

Climate change is exacerbating flood risks globally. In the United States, Federal Emergency Management Agency (FEMA) Flood Insurance Rate Maps (FIRMs) delineate areas at high flood risk (i.e., 100-year flood zones), however, FIRMs are outdated, incomplete, and subject to political maneuvering. We utilize state-of-the-art flood hazard modeling and sociodemographic data at the census tract level to examine federally-overlooked 100-year flood risk (100-year flood zones delineated by the flood hazard model that are outside of FEMA 100-year flood zones) inequities in the conterminous United States (CONUS). We examine inequities based on flood type (coastal, pluvial, and fluvial), as well as along the urban-rural continuum. Results indicate that nearly 28 million CONUS residents live in federally-overlooked 100-year flood zones. Lower income was associated with increased federally-overlooked 100-year flood risk for all flood types and across the urban-rural continuum. Results for racial/ethnic composition were mixed, but higher Black neighborhood composition was associated with increased risk to federally-overlooked 100-year pluvial flooding in metropolitan core areas, contexts which include 47 percent of the total CONUS population at federally-overlooked 100-year flood risk. In small town/rural contexts, higher Hispanic/Latinx neighborhood composition was associated with increased risk to federally-overlooked 100-year fluvial flooding. These inequities in federally-overlooked 100-year flood risk represent major public policy and environmental justice dilemmas that demand flood protection interventions.