According to Irvine- California based data company CoreLogic, 52 percent of residential and commercial properties in the Houston metro are at "High" or "Moderate" risk of flooding, but are not in a Special Flood Hazard Area (SFHA) as identified by the Federal Emergency Management Agency (FEMA).
Properties within SFHA zones, categorized as Extreme or Very High Risk, require flood insurance if the property has a federally insured mortgage. Properties outside SFHA zones are not required to carry flood insurance.
Table 1 below shows the levels of flood risk according to CoreLogic data for properties in seven metro areas likely to get severe rain and flooding as a result of Hurricane Harvey.
Table 2 shows only the total and percent of properties in the High and Moderate risk categories that are not in an SFHA and therefore not required to carry flood insurance.