How to Find Official Flood Maps for a Gwinnett County Property
Three official resources show whether an address sits in a mapped flood hazard area. Here is how to use them, what the terms mean, and what a map can’t tell you. Last reviewed October 31, 2026.
Understanding Flood Maps in Gwinnett County
Flood maps show where flooding from rivers and streams is expected under a defined standard, so homeowners, buyers and insurers can see mapped hazard areas. As of October 31, 2026, Gwinnett County’s flood information page reports that the county has approximately 24,000 acres of floodplain (Gwinnett County flood information).
That countywide figure is context, not a verdict on any one home. Whether a particular property is in a mapped flood hazard area depends on its exact location on the official maps below.
Start With the Gwinnett Flood Information Portal
Gwinnett County links residents to its Gwinnett Flood Information Portal for local floodplain information. Begin there to see the county’s floodplain data for an area, then confirm the official map for a specific address with FEMA.
Look Up a Property’s FEMA Flood Map
FEMA’s Flood Map Service Center holds the official flood maps used by the National Flood Insurance Program, and the county links to it directly. To use it:
- Open the Flood Map Service Center and type the property’s street address into the search box.
- Open the effective flood map shown for that address.
- Note the map panel number and its effective date.
- Check whether any map changes or amendments are listed for the area.
- Save or print a FIRMette, a printable excerpt of the official map, if you need one for your records.
Georgia’s Flood Mapping Program
The county also links to Georgia’s ongoing flood mapping, assessing and planning program at Georgia DFIRM. Use it for state mapping information; for the official map used for flood insurance, rely on FEMA’s Flood Map Service Center.
Flood Map Terms, Explained
| FIRM | Flood Insurance Rate Map: the official FEMA map of flood hazard areas for a community. |
|---|---|
| SFHA | Special Flood Hazard Area: the area expected to flood in a 1% annual chance flood. |
| 1% annual chance flood | A flood with a 1-in-100 chance of happening in any given year, often called the “100-year flood.” It can happen in back-to-back years. |
| BFE | Base Flood Elevation: the height floodwater is expected to reach in a 1% annual chance flood. |
| LOMA | Letter of Map Amendment: a FEMA letter that can remove a property or structure from the SFHA when it’s shown to sit above the base flood elevation. |
| LOMR | Letter of Map Revision: a FEMA change to the map itself, based on new data or physical changes to the land. |
Terms as used by FEMA’s National Flood Insurance Program; see FEMA flood maps.
Other Gwinnett County Flood Resources
- Elevation certificates are available for some residential properties, not all, through Gwinnett County’s Department of Planning and Development.
- The county’s flood information page also links its Flood Warning System document and its floodplain development permit requirements.
- Gwinnett County’s Floodplain Management Ordinance restricts construction within the floodplain; questions about building or map changes go to the county.
Source: Gwinnett County flood information (checked October 31, 2026).
What a Flood Map Can’t Tell You
A flood map is a planning and insurance tool. It is not:
- a home inspection;
- an assessment of an interior plumbing leak, a burst pipe or a failed water heater;
- a review of every private drainage problem on a lot;
- a guarantee that a property will or won’t flood.
Water Damage Gwinnett doesn’t determine any property’s flood risk. If water is already inside your home, from flooding or anything else, the steps on our flooded basement page apply, and we can route your call to an independent local restoration provider.
Water Damage Gwinnett Is Not the County or FEMA
We’re a referral and call-routing service. The county and FEMA maintain the maps above. For water damage cleanup inside your home, call (678) 833-0791 and we’ll route you to an independent restoration provider.
You’ll be connected with a local restoration provider.
Flood Map FAQs
Common questions about flood maps in Gwinnett County, answered plainly.
How do I find flood maps for my property in Gwinnett County?
Start with Gwinnett County's flood information page and the Gwinnett Flood Information Portal, then look up the address on FEMA's Flood Map Service Center, which holds the official maps used for flood insurance.
Where can I look up a FEMA flood zone by address?
On FEMA's Flood Map Service Center at msc.fema.gov. Enter the street address, open the effective map for that location, and note the panel number and effective date. You can save or print a FIRMette for your records.
What does a 1% annual chance flood mean?
It is a flood with a 1-in-100 chance of happening in any given year, often called the 100-year flood. The name is misleading: it can happen in back-to-back years. Special Flood Hazard Areas are mapped using this standard.
Does being outside a mapped flood zone mean a property cannot flood?
No. Maps show mapped flood hazards from rivers and streams. Heavy rain, poor drainage and plumbing failures can put water in any home. Gwinnett County also notes that standard homeowners insurance does not cover flood damage; flood coverage is a separate policy.
Where can I find an elevation certificate?
Gwinnett County says elevation certificates are available for some residential properties, not all, through its Department of Planning and Development. Check the county's flood information page for how to ask.
What should I do if I believe a FEMA flood map is incorrect?
FEMA has a map-change process. A Letter of Map Amendment can remove a property or structure from the Special Flood Hazard Area when it is shown to sit above the base flood elevation; a Letter of Map Revision changes the map based on new data. Gwinnett County's flood information page covers local map-change and floodplain development procedures.
Sources: Gwinnett County flood information · Gwinnett Flood Information Portal · FEMA Flood Map Service Center · Georgia DFIRM · Gwinnett County flood brochure (homeowners insurance and flood).