Flood Risk Assessment for Single-Family Home in A Zone

In the United States, the Federal Emergency Management Agency (FEMA) delineates 100-year flood zones (special flood hazard area (SFHA) in the U.S.A.) to define flood risks and insurance rates. Quantifying flood risk in the SFHA which is the area of high risk of flooding is vital for individual, communities, and decision makers to minimize flood consequences. Flood risk is assessed as the product of the probability of flooding and the consequences associated with its occurrence. The unavailability of the modeled flood depth data for 100- year return period or for all return periods in most of SFHA’s areas make quantifying flood risk is challenging. This research develops a systematic approach that generates a synthetic flood parameter to quantify flood risk in A Zone- portion of the SFHA in which the potential base flood wave height is between 0.0 and 3.0 feet. The synthetic flood hazard parameters are generated in 100-year floodplain considering different flooding scenarios, and the flood risk is quantified in terms of average annual loss (AAL) at 100-year flood elevation (E₁₀₀), and with an additional elevation above E₁₀₀ for single-family home with different attribute located in A Zone. The results reveal that the AAL for single-family home (i.e., one vs. two-plus stories, with vs. without basement), at E₁₀₀  and located in A Zone ranging of 0.27–0.98 percent of replacement cost value. The methodology and results generated in this research will benefit homeowners, engineers, surveyors, and community planners in enhancing resilience to the flood hazard in A Zone.