Audrain County, Missouri
The dominant drainage class is Poorly drained and the dominant hydrologic group is D (very slow infiltration, high 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 Audrain County, Missouri.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Mexico silt loam, 1 to 4 percent slopes, eroded | 116K | Poorly drained | D | Very limited | Very limited |
| Leonard silt loam, 1 to 6 percent slopes, eroded | 72K | Poorly drained | C/D | Very limited | Very limited |
| Mexico silt loam, 0 to 2 percent slopes | 55K | Poorly drained | D | Very limited | Very limited |
| Armstrong loam, 5 to 9 percent slopes, eroded | 54K | Somewhat poorly drained | D | Very limited | Very limited |
| Putnam silt loam, 0 to 1 percent slopes | 53K | Poorly drained | D | Very limited | Very limited |
| Keswick silt loam, 5 to 9 percent slopes, eroded | 26K | Somewhat poorly drained | D | Very limited | Very limited |
| Belknap silt loam, 0 to 2 percent slopes, frequently flooded | 17K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Twomile silt loam, 0 to 2 percent slopes, occasionally flooded | 12K | Poorly drained | C/D | Very limited | Very limited |
| Gifford silt loam, 1 to 4 percent slopes | 5K | Poorly drained | D | Very limited | Very limited |
| Chariton silt loam, 0 to 2 percent slopes, rarely flooded | 4K | Poorly drained | C/D | Very limited | Very limited |
| Belknap silt loam, 1 to 3 percent slopes, frequently flooded | 4K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Marion silt loam, 2 to 5 percent slopes | 4K | Somewhat poorly drained | D | Very limited | Very limited |
| Keswick silt loam, 9 to 14 percent slopes, eroded | 4K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Twomile silt loam, 1 to 3 percent slopes, rarely flooded | 3K | Poorly drained | C/D | Very limited | Very limited |
| Winnegan loam, bedrock substratum, 9 to 14 percent slopes, eroded | 2K | Moderately well drained | D | Very limited | Very limited |
| Water | 2K | Subaqueous | Not rated | Not rated | |
| Armstrong clay loam, 5 to 9 percent slopes, severely eroded | 2K | Somewhat poorly drained | D | Very limited | Very limited |
| Winnegan silt loam, 14 to 30 percent slopes | 2K | Moderately well drained | D | Very limited | Very limited |
| Goss cobbly silt loam, 14 to 30 percent slopes | 1K | Well drained | C | Very limited | Very limited |
| Lenzburg clay loam, 5 to 50 percent slopes | 1K | Well drained | C | Very limited | Very limited |
What This Means
Building & Foundations
About 99% 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 99% 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.