Smyth County, Virginia
The most common soil here is Frederick, on about 16% of the land: a silt loam, smooth, like flour. Carbo and Lily come next.
About 97% of the land drains well; groundwater comes within two feet of the surface under 2% of it.
USDA rates 83% of the land very limited for a standard septic drain field, and 83% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 4% of the land floods occasionally or more, and bedrock lies within 40 inches under 56% of it.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The soils you're most likely standing on
The biggest named soils in Smyth County, Virginia, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
The biggest mapped areas
The dominant drainage class is Well drained and the dominant hydrologic group is B (moderate infiltration). The most common soil order is Ultisols — strongly weathered soils with clay-enriched subsoils, common in warm humid climates. 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 Smyth County, Virginia. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Weikert-Berks complex, 35 to 70 percent slopes | 21K | Well drained | D | Very limited | Very limited |
| Carbo-Rock outcrop complex, 25 to 65 percent slopes | 18K | Well drained | D | Very limited | Very limited |
| Lily sandy loam, 25 to 65 percent slopes, very stony | 14K | Well drained | B | Very limited | Very limited |
| Chiswell-Litz-Groseclose complex, 25 to 65 percent slopes | 10K | Well drained | C | Very limited | Very limited |
| Newbern-Westmoreland complex, 25 to 65 percent slopes | 10K | Somewhat excessively drained | D | Very limited | Very limited |
| Frederick silt loam, 15 to 25 percent slopes | 9K | Well drained | B | Very limited | Very limited |
| Frederick silt loam, 8 to 15 percent slopes | 8K | Well drained | B | Somewhat limited | Somewhat limited |
| Frederick gravelly silt loam, 15 to 25 percent slopes | 7K | Well drained | B | Very limited | Very limited |
| Wurno-Newbern complex, 25 to 65 percent slopes | 7K | Well drained | C | Very limited | Very limited |
| Tumbling loam, 7 to 15 percent slopes | 5K | Well drained | B | Somewhat limited | Somewhat limited |
| Carbo-Rock outcrop complex, 7 to 25 percent slopes | 4K | Well drained | D | Very limited | Very limited |
| Frederick gravelly silt loam, 7 to 15 percent slopes | 4K | Well drained | B | Somewhat limited | Somewhat limited |
| Tumbling loam, 15 to 25 percent slopes, very stony | 4K | Well drained | B | Very limited | Very limited |
| Chiswell-Litz-Groseclose complex, 15 to 25 percent slopes | 4K | Well drained | C | Very limited | Very limited |
| Frederick gravelly silt loam, 25 to 35 percent slopes | 4K | Well drained | B | Very limited | Very limited |
| Dekalb channery sandy loam, 25 to 80 percent slopes, extremely stony | 4K | Well drained | A | Very limited | Very limited |
| Frederick silt loam, 35 to 60 percent slopes | 4K | Well drained | B | Very limited | Very limited |
| Lily sandy loam, 15 to 25 percent slopes, very stony | 4K | Well drained | B | Very limited | Very limited |
| Frederick silt loam, 25 to 35 percent slopes | 3K | Well drained | B | Very limited | Very limited |
| Wyrick-Marbie complex, 7 to 15 percent slopes | 3K | Well drained | B | Somewhat limited | Somewhat limited |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
What This Means
Building & Foundations
About 83% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes. A geotechnical assessment is recommended before building.
Septic Systems
About 83% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.