FEMA has a pretty good online mapping tool for flood insurance maps but if you are a fan of Google Earth, there is a nice overlay for that too. You need to have downloaded Google Earth to your computer. Then you simply add on one of FEMA’s map layers to the program through another download here.
FEMA offers two free overlays for Google Earth: “Stay Dry” is a focused application that provides basic flood hazard map information from FEMA’s National Flood Hazard Layer for an address. It allows you to view flood hazard zones, cross sections and their labels, community names and boundaries, Flood Insurance Rate Map numbers and boundaries, and Letter of Map Revision case numbers and boundaries.
“FEMA NFHL” offers multiple layers of information. It is a general application that provides for the display of flood hazard zones, floodways, Coastal Barrier Resources System and Otherwise Protected Area units, community boundaries and names, base flood elevations, cross sections and coastal transects and their labels, hydraulic and flood control structures, and Flood Insurance Rate Map and Letter of Map Revision boundaries and numbers. Additional reference layers include the status of NFHL data availability, point locations for Letters of Map Amendment (LOMAs) and Letters of Map Revision Based on Fill (LOMR–Fs), Q3 base flood, and subbasin hydrologic units. You control the information displayed by turning layers on and off. A basic knowledge of Google Earth and FEMA flood hazard information will help users of this application.