Flood insurance is based on a number of factors. These factors include: the amount and type of coverage being purchased, the location and flood zone, and the design and age of your structure. For homes in high-risk areas (e.g., Special Flood Hazard Areas or AE, VE Zones) built after the first Flood Insurance Rate Maps were drawn for that community, the elevation of the building in relation to the base flood elevation is also required. The elevation is called a BFE (base flood elevation). If you have a property in mind, contact a local insurance agent for a quote.
Keep in mind too that because of recent reforms to the Flood Insurance Program implemented by Congress, the current flood insurance rates are subject to potential increases each year until the rates reach market rates (many older homes have been benefiting from subsidized rates for years).