Who owns the flood plain? A parcel-level analysis of organizational form and flood risk

Regulatory flood maps define the geography of hazard but obscure the organizational structure of exposure. This study examines how regulatory flood exposure is distributed across owner-of-record forms and local portfolio footprints using the complete 2022 inventory of single-family residential parcels in Douglas County, Nebraska (N = 183,313). We classify owners into five organizational forms (including Individuals, LLCs, and Corporations) and distinguish between single-parcel and multi-parcel local portfolios. While only 1.10% of parcels fall within FEMA Special Flood Hazard Areas (SFHAs) in aggregate, prevalence varies sharply by ownership structure. Unadjusted SFHA rates are highest among single-parcel Limited Liability Companies (4.83%) and single-parcel corporations (4.07%), compared to 0.81% for single-parcel individuals. In modified Poisson models with neighborhood fixed effects, LLC-owned parcels retain elevated exposure relative to individuals (adjusted Risk Ratio for single-parcel LLCs = 1.67; 95% CI: 1.31–2.13). Multi-parcel individuals and trusts also exhibit elevated prevalence. These findings demonstrate that flood exposure is not just a spatial attribute but an organizational one, concentrated within specific legal structures. Consequently, effective flood governance requires implementation strategies capable of navigating diverse legal forms and portfolio scales for mitigation and compliance.