Flood Zones: Alpharetta vs Roswell
How do flood zones rules compare between Alpharetta, GA and Roswell, GA?
Alpharetta and Roswell have similar restriction levels.
Alpharetta, GA
Fulton County
Fulton County participates in the FEMA NFIP and enforces flood-damage prevention through Chapter 26 Article IV (Stormwater) and Article XXVI (Flood Damage Prevention). Construction in mapped Special Flood Hazard Areas requires elevation and permits.
View full Alpharetta rules →Roswell, GA
Fulton County
Properties along the Chattahoochee River and Big Creek in Roswell sit within FEMA Special Flood Hazard Areas (Zone AE). New construction or substantial improvement in those zones requires elevation to at least 1 foot above Base Flood Elevation (BFE), a floodplain development permit, and an Elevation Certificate.
View full Roswell rules →Key Facts Comparison
| Fact | Alpharetta | Roswell |
|---|---|---|
| Freeboard | 3 ft above BFE | 1 ft above BFE |
| Major river | Chattahoochee | - |
| Substantial improvement | 50% threshold | - |
| FEMA Zones in Roswell | - | AE (Chattahoochee, Vickery, Big Creek) |
| Substantial Improvement | - | >50% of pre-value |
| Elevation Certificate | - | Required at final |
| Permit | - | Floodplain development permit |
Highlighted rows indicate differences between cities.
Alpharetta FAQ
Is my house in an SFHA?
Check FEMA Flood Map Service Center (msc.fema.gov) using your address.
Do I need flood insurance?
Required for federally backed mortgages in AE/A zones; recommended for X zones near streams.
Roswell FAQ
Is my Roswell home in a flood zone?
Check FEMA's Flood Map Service Center (msc.fema.gov) by address. Properties along the Chattahoochee River, Vickery Creek, and Big Creek frequently fall in Zone AE with mapped BFEs.
How high do I have to build in a Roswell flood zone?
The lowest floor (including basement) must be elevated at least 1 foot above the Base Flood Elevation shown on the FIRM. That is more conservative than FEMA's federal minimum.
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