A floodplain is an area of low-lying land next to a stream or river that is susceptible to flooding. Floodplains are beneficial to our overall ecosystem—water quality is improved through the wetlands’ ability to filter nutrients and impurities from runoff and process organic wastes. Gwinnett County has approximately 24,000 acres of floodplain. Our Floodplain Management Ordinance prohibits construction within the floodplain. A home built on a floodplain lot is required to be elevated three feet above the 100-year Base Flood Elevation (BFE).

DWR works to protect people's lives and property during extreme flooding events such as the 100-year flood. Gwinnett County is a participating community in the Federal Emergency Management Agency (FEMA) National Flood Insurance Program, which provides us with Flood Insurance Rate Maps (FIRMs) that identify the 100-year floodplain.

The National Weather Service, along with the Gwinnett County Emergency Management Agency, provides flood warning and evacuation information to local radio and television stations. Gwinnett County Police and Fire Departments will provide door to door warnings to those areas threatened by flooding. When a flood threatens, evacuations are ordered in areas expected to flood. Residents must be prepared to move to a place of safety.

Visit the Gwinnett Flood Information Portal to find specific information about flooding sources in your area. Use the links below for more general flood information and tips. For information on existing elevation certificates for some residential properties, visit the Department of Planning and Development.

Homeowner Tips

Before you commit yourself to buying property:

• Check your flood hazard. Flood maps and flood protection references are available at all Gwinnett County Public libraries.
• You can also visit the Department of Planning and Development’s Storm/Water/Sewer Plan Review page to see if you are in a mapped floodplain. Planning and Development can give you information on the depth of flooding over a building's first floor and past flood problems in the area.
• Ask the real estate agent if the property is in a floodplain, if it has ever been flooded, and if it is subject to any other hazards, such as sewer backup or subsidence.
• Ask the seller and the neighbors if the property is in a floodplain, how long they have lived there, if the property has ever been flooded, and if it is subject to any other hazards.
• If requested, Storm/Water/Sewer Plan Review staff will visit a property to review its flood problem and explain ways to mitigate the effects of flood damage. Call the Department of Planning and Development at 678.518.6000 to make this request and get more information. 

Flood Protection: A building can be protected from some flood hazards, sometimes at a relatively low cost. New buildings and additions can be elevated above flood levels. Existing buildings can be protected from shallow floodwaters by re-grading, berms, or floodwalls. There are also other retrofitting techniques that can protect a building from surface or subsurface water.

Flood Insurance: Homeowners insurance policies do not include coverage for a flood. One of the best protection measures for a building with a flood problem is National Flood Insurance, which is purchased through any property insurance agent. If the building is in a floodplain, flood insurance will be required by most mortgage lenders. Ask an insurance agent how much a flood insurance policy would cost.

More Information

• Gwinnett Flood Information Portal
• Ongoing Georgia Flood Mapping, Assessing, and Planning Program
• FEMA Flood Map Service Center
• FEMA Evacuation Safety Tips
• FloodSmart.gov – the National Flood Insurance Program Official Website
• National Flood Insurance Program Elevation Certificate and Instructions
• Processing Letters of Map Amendment Or Revision (PDF)