Flooding is one of the most widespread and damaging natural perils in the United States. JBA estimates that nearly one in three buildings, over 38 million properties, face some level of inland flood risk. Crucially, 78% of fluvial-risk properties lie outside FEMA’s designated flood zones, exposing a significant protection gap in the current flood insurance landscape.
This reality, coupled with increasing flood losses and climate-driven volatility, underscores the need for reliable, high-resolution flood models tailored to the insurance sector. With many events, such as Hurricanes Harvey, Helene, and Milton, causing devastating flood losses outside mapped zones, the demand for transparent, independent risk insight has never been greater.
Meeting a growing market need
The National Flood Insurance Program (NFIP) has been central to US flood coverage for decades, but its rigid framework and outdated data have created blind spots. As private insurers and reinsurers enter the market, they need better tools to price flood risk accurately, extend coverage, and complement federal efforts. JBA’s US Inland Flood Model directly meets these requirements.
Developed specifically for the US insurance market, the model offers granular, building-level insights, extensive coverage across the mainland US, and a probabilistic foundation compatible with technical pricing, portfolio accumulation, reinsurance structuring, and regulatory compliance.
Science-led and event-based
Built on JBA’s proprietary 5m resolution flood maps, the model simulates both fluvial (riverine) and pluvial (surface water) flood risk through a continuous time-series hydrological workflow. It includes over 18 million flood events across 500,000 simulation years, delivering consistent flood footprints at national scale. High-resolution terrain data, including LiDAR, allows insurers to assess risk beyond FEMA zones and tailor coverage to individual properties.
Correlated hurricane and flood risk
In partnership with Applied Research Associates (ARA), JBA has aligned its inland flood model with ARA’s HurLoss® hurricane model. This allows for fully correlated simulations of wind, surge, and flood - preserving temporal and spatial coherence of tropical storm impacts. The models are designed to be used independently or jointly, giving insurers a comprehensive view of compound risk from hurricanes, increasingly important in an era of wetter, slower-moving storms.