Lewis County, Tennessee
The dominant drainage class is Somewhat excessively drained and the dominant hydrologic group is B (moderate infiltration). This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in Lewis County, Tennessee.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Biffle-Sulphura-Rock outcrop association, very steep | 79K | Somewhat excessively drained | B | Very limited | Very limited |
| Lax-Ironcity complex, 5 to 12 percent slopes | 19K | Moderately well drained | D | Very limited | Very limited |
| Biffle gravelly silt loam, 5 to 15 percent slopes | 12K | Somewhat excessively drained | B | Somewhat limited | Very limited |
| Ironcity gravelly silt loam, 5 to 12 percent slopes | 11K | Well drained | B | Somewhat limited | Somewhat limited |
| Biffle gravelly silt loam, 15 to 30 percent slopes | 11K | Somewhat excessively drained | B | Very limited | Very limited |
| Riverby gravelly sandy loam, frequently flooded | 9K | Excessively drained | A | Very limited | Very limited |
| Dickson silt loam, 2 to 5 percent slopes | 7K | Moderately well drained | C/D | Very limited | Very limited |
| Biffle gravelly silt loam, 30 to 60 percent slopes | 7K | Somewhat excessively drained | B | Very limited | Very limited |
| Tarklin-Humphreys complex, 5 to 12 percent slopes, eroded | 3K | Moderately well drained | D | Very limited | Very limited |
| Humphreys gravelly silt loam, 2 to 5 percent slopes | 2K | Well drained | A | Somewhat limited | Very limited |
| Rock outcrop, very steep | 2K | D | Not rated | Not rated | |
| Trace silt loam, 0 to 2 percent slopes, occasionally flooded | 2K | Well drained | B | Very limited | Very limited |
| Humphreys gravelly silt loam, 5 to 12 percent slopes | 2K | Well drained | A | Somewhat limited | Very limited |
| Lobelville silt loam, occasionally flooded | 2K | Moderately well drained | C | Very limited | Very limited |
| Lax silt loam, 2 to 5 percent slopes | 1K | Moderately well drained | D | Very limited | Very limited |
| Paden silt loam, 2 to 5 percent slopes | 1K | Moderately well drained | C | Very limited | Very limited |
| Tarklin gravelly silt loam, 5 to 12 percent slopes, eroded | 1K | Moderately well drained | D | Very limited | Very limited |
| Urban land | 1K | Not rated | Not rated | ||
| Lee gravelly silt loam, frequently flooded | 1K | Poorly drained | B/D | Very limited | Very limited |
| Trace silt loam, 2 to 5 percent slopes, rarely flooded | 817 | Well drained | B | Very limited | Very limited |
What This Means
Building & Foundations
About 82% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, poor drainage in some areas, flood-prone areas, sandy or gravelly soils with low bearing capacity. A geotechnical assessment is recommended before building.
Septic Systems
About 92% of soils are rated "very limited" for septic absorption fields. The well-drained soils may actually drain too fast for standard leach fields, allowing effluent to reach groundwater. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Soils tend to drain very quickly, meaning nutrients and water don't stick around long. Raised beds with amended soil, drip irrigation, and heavy mulching will give the best results. Compost is your best friend here — it improves water retention dramatically.