Johnson County, Missouri
The most common soil here is Sampsel, on about 19% of the land: a silty clay loam, smooth and slightly sticky. Deepwater and Snead come next.
About 20% of the land drains well, and 52% stays wet for long stretches; groundwater comes within two feet of the surface under 42% of it.
USDA rates all of the land very limited for a standard septic drain field, and 76% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 15% of the land floods occasionally or more, and bedrock lies within 40 inches under 23% 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 Johnson County, Missouri, 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 Somewhat poorly drained and the dominant hydrologic group is C (slow infiltration, moderate runoff). The most common soil order is Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter. 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 Johnson County, Missouri. 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 |
|---|---|---|---|---|---|
| Sampsel silty clay loam, 5 to 9 percent slopes, severely eroded | 79K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Deepwater silt loam, 5 to 9 percent slopes, eroded | 35K | Moderately well drained | C | Somewhat limited | Very limited |
| Mandeville silt loam, 5 to 9 percent slopes | 32K | Well drained | C | Somewhat limited | Very limited |
| Haig silt loam, 0 to 2 percent slopes | 29K | Poorly drained | D | Very limited | Very limited |
| Sampsel silty clay loam, 2 to 5 percent slopes | 27K | Poorly drained | C/D | Very limited | Very limited |
| Arisburg silt loam, 1 to 5 percent slopes | 24K | Somewhat poorly drained | C | Very limited | Very limited |
| Snead silty clay loam, warm, 5 to 14 percent slopes, eroded | 23K | Moderately well drained | D | Very limited | Very limited |
| Deepwater silt loam, 2 to 5 percent slopes | 23K | Moderately well drained | C | Somewhat limited | Very limited |
| Polo silt loam, 2 to 5 percent slopes | 18K | Well drained | C | Very limited | Very limited |
| Norris channery silt loam, 5 to 14 percent slopes | 16K | Well drained | D | Very limited | Very limited |
| Nodaway silt loam, heavy till, 0 to 2 percent slopes, occasionally flooded | 16K | Moderately well drained | B | Very limited | Very limited |
| Gorin silt loam, 5 to 9 percent slopes, eroded | 14K | Somewhat poorly drained | C | Very limited | Very limited |
| Zook silty clay loam, 0 to 2 percent slopes, frequently flooded | 14K | Poorly drained | C/D | Very limited | Very limited |
| Hartwell silt loam, 1 to 3 percent slopes, eroded | 13K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Hartwell silt loam, 0 to 1 percent slopes | 12K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Nodaway silt loam, 1 to 3 percent slopes, occasionally flooded | 11K | Moderately well drained | B | Very limited | Very limited |
| Dockery silty clay loam, 0 to 2 percent slopes, frequently flooded | 11K | Somewhat poorly drained | C | Very limited | Very limited |
| Snead-Rock outcrop complex, warm, 5 to 14 percent slopes | 11K | Moderately well drained | D | Very limited | Very limited |
| Weller silt loam, 2 to 5 percent slopes | 10K | Moderately well drained | D | Very limited | Very limited |
| Snead-Rock outcrop complex, warm, 14 to 30 percent slopes | 9K | Moderately well drained | D | Very limited | Very 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 76% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 100% of soils are rated "very limited" for septic absorption fields. Poorly drained soils can't absorb septic effluent effectively. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Many soils hold water for extended periods. Raised beds are highly recommended to improve drainage for vegetables. Well-adapted native plants and water-loving species will do best in natural conditions.