County soil summary
Soil types in Iredell County, North Carolina
The most widespread soils are Tomlin, Fairview and Cecil; the most common drainage class is well drained (88% of the land), and typical topsoil pH is 5.7.
- Well or moderately well drained
- 89% of land · state 68%
- Typical topsoil pH
- 5.7 moderately acidic · state 5.2
- Septic fields very limited
- 50% of land · state 76%
- Subject to flooding
- 9% of land, any frequency · state 18%
Most common soils in Iredell County
Share of mapped land
A county is a patchwork of many soils. These 8 cover 70% of the mapped land; 74 named soil series are mapped here in all.
| Soil | Share of land | Drainage | Topsoil pH |
|---|---|---|---|
| Tomlin | 13.7% | Well drained | 5.5 |
| Fairview | 13.6% | Well drained | 5.7 |
| Cecil | 10.7% | Well drained | 5.5 |
| Pacolet | 9.9% | Well drained | 5.5 |
| Clifford | 9.2% | Well drained | 5.5 |
| Lloyd | 5.0% | Well drained | 5.5 |
| Urban landLand type, not a soil series | 4.5% | — | — |
| UdorthentsGeneral soil group, not a named series | 3.6% | — | — |
What this means
What the soils in Iredell County mean for gardens, lawns and septic systems
For your garden
Typical topsoil in Iredell County is moderately acidic: pH 5.7 (most land between 5.4 and 6.3). 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 94% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is sandy clay loam (58% of the land).
89% of the land is moderately well to excessively drained, which suits most garden plants.
For your lawn and yard
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 50% of the land in Iredell County very limited, 46% somewhat limited and 0% not limited (5% not rated, such as urban land, pits or water).
Statewide, 76% of the land is very limited, so Iredell County is less restrictive than typical.
Flooding is mapped on 9% of the land (2% occasional, 6% frequent).
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Drainage
How long the soil stays wet
The most common drainage class is well drained (88%). 89% of the land is moderately well drained or better, compared with 68% across North Carolina.
Show as a table
| Category | Iredell County | North Carolina |
|---|---|---|
| Excessively drained | 0.4% | 1.0% |
| Somewhat excessively drained | 0.0% | 2.8% |
| Well drained | 87.9% | 54.2% |
| Moderately well drained | 1.1% | 10.4% |
| Somewhat poorly drained | 5.4% | 5.4% |
| Poorly drained | 0.6% | 12.4% |
| Very poorly drained | 0.1% | 11.6% |
| Not rated | 4.5% | 2.3% |
Septic absorption fields
NRCS rating for conventional drain fields
The rating looks at the soil from 24 to 60 inches deep: permeability, depth to a seasonal water table or bedrock, flooding and slope. “Very limited” means at least one feature is unfavorable enough that a conventional field is hard to make work.
Show as a table
| Category | Iredell County | North Carolina |
|---|---|---|
| Not limited | 0.0% | 0.0% |
| Somewhat limited | 45.9% | 21.4% |
| Very limited | 49.5% | 76.4% |
| Not rated | 4.6% | 2.2% |
Rain, runoff and water table
Hydrologic soil group, flooding, seasonal water table
Hydrologic soil group
How fast rain soaks in when the soil is already wet. Group A soaks in fastest, D slowest.
Show as a table
| Category | Iredell County | North Carolina |
|---|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 2.5% | 11.8% |
| B: moderate infiltration | 64.2% | 35.7% |
| C: slow infiltration | 21.9% | 14.5% |
| D: very slow infiltration (clayey, shallow or wet) | 0.4% | 7.4% |
| A/D: D as is, A if drained | 0.2% | 10.6% |
| B/D: D as is, B if drained | 5.3% | 11.1% |
| C/D: D as is, C if drained | 0.7% | 7.1% |
| Not rated | 4.7% | 1.8% |
Flooding
Show as a table
| Category | Iredell County | North Carolina |
|---|---|---|
| No flooding | 91.0% | 81.9% |
| Rare or very rare | 1.1% | 7.5% |
| Occasional | 1.9% | 1.5% |
| Frequent or very frequent | 5.8% | 8.9% |
| Not reported | 0.1% | 0.2% |
Seasonal high water table
Show as a table
| Category | Iredell County | North Carolina |
|---|---|---|
| Within 18 inches at some time of year | 6.4% | 29.5% |
| 18 inches to 3.3 feet | 1.9% | 11.3% |
| Deeper than 3.3 feet or none reported | 91.6% | 59.0% |
| Not reported | 0.1% | 0.2% |
Topsoil pH and texture
First mineral layer of each soil
Typical topsoil pH is 5.7 (moderately acidic); 80% of rated land falls between 5.4 and 6.3. Median topsoil organic matter is 1%.
Show as a table
| Category | Iredell County | North Carolina |
|---|---|---|
| Strongly acidic (below 5.5) | 10.4% | 61.7% |
| Moderately to slightly acidic (5.5–6.4) | 83.8% | 33.5% |
| Near neutral (6.5–7.3) | 1.2% | 2.3% |
| Alkaline (7.4 and up) | 0.0% | 0.2% |
| Not reported | 4.7% | 2.3% |
Texture
Show as a table
| Category | Iredell County | North Carolina |
|---|---|---|
| Sandy | 0.9% | 24.0% |
| Loamy (loam, silt loam and similar) | 94.4% | 69.0% |
| Clayey (40%+ clay) | 0.0% | 0.0% |
| Organic (muck or peat) | 0.0% | 5.1% |
| Not reported (rock, urban land, etc.) | 4.7% | 1.8% |
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
- Iredell County, North Carolina (FIPS 37097): 350,922 acres of mapped land, 14,746 acres of open water excluded. State comparisons pool all mapped land in North Carolina.
- Method
- Shares are by mapped land area: each map unit’s acres in the county times each soil component’s percentage. Open water is excluded. Topsoil values use the first mineral horizon of each component. Full methodology.