Flood Risk on Your Property

Check Your Location


The first thing you should do is check the flood hazard at your location. By entering your address in the appropriate fields on the official National Flood Insurance Program website, you can immediately learn about the predicted risk of flooding at your location.

In addition, flood maps as well as information on local flood hazard are available at the County Public Library.

Also, you can determine if your property is located in a mapped floodplain by requesting assistance from a planner through DCD's Customer Assistance Service.

Understanding Floodplain Maps


If your property lies within a mapped floodplain, the planner will give you more information, such as the base elevation above which flooding is estimated to have a 1% chance of occurring in any given year (i.e., "a 100-year event"). This elevation is used to determine the minimum elevation of the lowest floor for the structures you plan to construct on your property (Jefferson County Code or "JCC" 15.15.70), as well as the minimum elevation of a structure that will be substantially improved (see Definition of Substantially improved in JCC 15.15.030). If your house is already built and you know the elevation of your house, you will be able to determine the estimated level of flooding that you may expect in your house.

Finally, you can check the baseline elevations of the newly constructed buildings in your area. These are noted on the Elevation Certificates that are required since June 2006 for every new structure or substantially improved structure in the floodplain in Jefferson County. You can view scanned copies of the elevation certificates online.

Dangers of Floodwaters


Remember that floods generate serious risks to people and property. Flood waters are contaminated with human, animal and industrial waste and are a breeding ground for bacteria. A flood 6 inches deep can knock people off their feet. It could take only 2 feet of water to float a car away or cause the car to flip, trapping persons inside. Keep in mind that during a typical 30-year mortgage period, a home in a mapped flood plain has about a 26 percent chance of being damaged by a 100-year flood event. The same structure only has about a one-percent chance of being damaged by fire (source: U.S. Geological Survey [USGS]).