Soil series profile
Gwinnett soil series
Gwinnett is a well drained soil with a clay loam surface, mapped on 435,394 acres in 42 counties across 3 states. Hydrologic group B.
- Drainage class
- Well drained 100% of mapped acres
- Hydrologic group
- B 91% of mapped acres
- Typical topsoil pH
- 5.8 moderately acidic · range 5.8–5.8
- Mapped area
- 435k acres in 42 counties, 3 states
Typical Gwinnett profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–8 in (H1) | Clay loam | 5.8 | 30% | 34% | 2% |
| 8–35 in (H2) | Clay | 5.8 | 48% | 23% | 0.25% |
| 35–50 in (H3) | Clay loam | 5.8 | 32% | 35% | 0.25% |
| 50–53 in (Cr) | Weathered bedrock | Not reported | Not reported | Not reported | Not reported |
What this means
What Gwinnett soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Gwinnett soils is moderately acidic: pH 5.8. Many vegetables grow well here, and some gardens benefit from a little lime. Test before adding any.
Loamy topsoil (loam, silt loam and similar) covers 100% of mapped Gwinnett acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is clay loam (30% of mapped Gwinnett acres).
100% of mapped Gwinnett acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
Most land is in hydrologic groups B and C, where rain soaks in at a moderate pace.
For a septic system
For conventional septic absorption fields, NRCS rates 36% of the acres in mapped Gwinnett soils very limited, 64% somewhat limited and 0% not limited.
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Where Gwinnett soil is found
Mapped acres
Gwinnett is mapped in Georgia, Alabama and South Carolina.
| County | Acres | Share of county land |
|---|---|---|
| Cobb County, GA | 39,386 | 18.2% |
| Gwinnett County, GA | 36,340 | 13.6% |
| Carroll County, GA | 32,655 | 10.3% |
| Walton County, GA | 30,496 | 14.6% |
| Franklin County, GA | 28,275 | 17.0% |
| Tallapoosa County, AL | 28,201 | 6.9% |
| Henry County, GA | 22,204 | 10.9% |
| Newton County, GA | 21,260 | 12.1% |
| Cherokee County, GA | 19,215 | 7.3% |
| Hall County, GA | 18,485 | 7.4% |
| Jasper County, GA | 18,265 | 7.8% |
| Lee County, AL | 18,048 | 5.3% |
| Troup County, GA | 15,075 | 5.7% |
| DeKalb County, GA | 10,265 | 6.0% |
| Jackson County, GA | 8,345 | 3.9% |
| Barrow County, GA | 7,600 | 7.4% |
| Fayette County, GA | 7,420 | 5.9% |
| Banks County, GA | 7,212 | 4.9% |
| Clayton County, GA | 6,907 | 7.3% |
| Stephens County, GA | 6,069 | 5.3% |
| Madison County, GA | 5,775 | 3.2% |
| Putnam County, GA | 4,870 | 2.2% |
| Anderson County, SC | 4,826 | 1.1% |
| Douglas County, GA | 4,660 | 3.7% |
| Jones County, GA | 4,530 | 1.8% |
| Habersham County, GA | 4,295 | 2.4% |
| Haralson County, GA | 4,240 | 2.4% |
| Oconee County, GA | 3,640 | 3.1% |
| Clay County, AL | 3,609 | 1.0% |
| Rockdale County, GA | 2,972 | 3.5% |
| Hart County, GA | 2,920 | 2.0% |
| Clarke County, GA | 2,000 | 2.6% |
| Cleburne County, AL | 1,193 | 0.4% |
| Coweta County, GA | 975 | 0.4% |
| Heard County, GA | 675 | 0.4% |
| Morgan County, GA | 655 | 0.3% |
| Pickens County, GA | 585 | 0.4% |
| Abbeville County, SC | 277 | 0.1% |
| Baldwin County, GA | 275 | 0.2% |
| Fulton County, GA | 268 | 0.1% |
| Gilmer County, GA | 260 | 0.1% |
| Elbert County, GA | 170 | 0.1% |
Septic absorption fields
NRCS rating, share of Gwinnett acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 63.6% |
| Very limited | 36.4% |
Drainage, water table and flooding
Share of Gwinnett acres
- Depth to seasonal high water table
- None reported within about 6.5 feet (median where reported).
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 4–20% (median 8%).
- Topsoil organic matter
- Median 2%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 100.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| Very poorly drained | 0.0% |
Hydrologic soil group
Show as a table
| Category | Share of acres |
|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 0.0% |
| B: moderate infiltration | 90.5% |
| C: slow infiltration | 1.0% |
| D: very slow infiltration (clayey, shallow or wet) | 8.5% |
| A/D: D as is, A if drained | 0.0% |
| B/D: D as is, B if drained | 0.0% |
| C/D: D as is, C if drained | 0.0% |
Sources & data dates
- Source
- USDA NRCS Soil Survey Geographic Database (SSURGO), queried through Soil Data Access. Public domain.
- Data date
- SSURGO as published on November 3, 2026 (most recent survey area update October 26, 2026). NRCS refreshes SSURGO each October.
- Scope
- All map unit components named Gwinnett (component kind "Series") in SSURGO: 435,394 acres.
- Method
- Shares are by mapped acres of Gwinnett components. The profile comes from the single largest Gwinnett component. Full methodology.