If your house is in the floodplain according to the FEMA maps, you may be required by your lender to purchase flood insurance. If your house is in the floodplain but you do not have a mortgage, then it is your personal decision whether or not to buy flood insurance. There may be some advantage to purchasing flood insurance before the new maps become effective. Certain properties where the floodplain status has changed may be "grandfathered" and reduced rates may apply for insurance purchased before the new maps become effective.
Contact your insurance agent for more information.