Polk County, Missouri
The dominant drainage class is Moderately well drained and the dominant hydrologic group is C (slow infiltration, moderate runoff). 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 Polk County, Missouri.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Viraton silt loam, 2 to 5 percent slopes | 43K | Moderately well drained | D | Very limited | Very limited |
| Ocie-Gatewood complex, 3 to 15 percent slopes, stony | 31K | Moderately well drained | C | Very limited | Very limited |
| Mano-Ocie complex, 8 to 15 percent slopes, stony | 25K | Moderately well drained | C | Very limited | Very limited |
| Goss gravelly silt loam, 8 to 15 percent slopes | 23K | Well drained | C | Somewhat limited | Very limited |
| Pomme silt loam, 3 to 8 percent slopes | 23K | Well drained | B | Not limited | Somewhat limited |
| Goss gravelly silt loam, 3 to 8 percent slopes | 21K | Well drained | C | Not limited | Very limited |
| Hoberg silt loam, 2 to 5 percent slopes | 17K | Moderately well drained | C | Very limited | Very limited |
| Bona gravelly silt loam, 3 to 8 percent slopes | 17K | Well drained | C | Somewhat limited | Very limited |
| Barden silt loam, 1 to 3 percent slopes | 13K | Moderately well drained | D | Very limited | Very limited |
| Creldon silt loam, 1 to 3 percent slopes | 12K | Moderately well drained | C | Very limited | Very limited |
| Alsup silt loam, 15 to 35 percent slopes, very stony | 11K | Moderately well drained | D | Very limited | Very limited |
| Bolivar loam, 3 to 8 percent slopes | 11K | Well drained | C | Somewhat limited | Very limited |
| Sturkie silt loam, 0 to 2 percent slopes, frequently flooded | 11K | Well drained | B | Very limited | Very limited |
| Hartville silt loam, 3 to 8 percent slopes | 10K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Sacville silty clay loam, 1 to 3 percent slopes | 8K | Poorly drained | C/D | Very limited | Very limited |
| Cedargap gravelly silt loam, 1 to 3 percent slopes, frequently flooded | 8K | Well drained | B | Very limited | Very limited |
| Moko-Rock outcrop complex, 15 to 35 percent slopes, extremely flaggy | 8K | Somewhat excessively drained | D | Very limited | Very limited |
| Alsup gravelly silt loam, 8 to 15 percent slopes | 7K | Moderately well drained | D | Somewhat limited | Very limited |
| Goodson gravelly silt loam, 3 to 8 percent slopes | 7K | Moderately well drained | C | Somewhat limited | Very limited |
| Alsup gravelly silt loam, 3 to 8 percent slopes | 7K | Moderately well drained | C | Somewhat limited | Very limited |
What This Means
Building & Foundations
About 63% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 92% 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.