Montgomery County, Illinois
The dominant drainage class is Somewhat poorly drained and the dominant hydrologic group is C/D (varies with drainage). 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 Montgomery County, Illinois.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Virden silty clay loam, 0 to 2 percent slopes | 51K | Poorly drained | C/D | Very limited | Very limited |
| Herrick silt loam, 0 to 2 percent slopes | 50K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Herrick-Biddle-Piasa silt loams, 0 to 2 percent slopes | 50K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Cowden-Piasa silt loams, 0 to 2 percent slopes | 33K | Poorly drained | D | Very limited | Very limited |
| Oconee-Darmstadt-Coulterville silt loams, 2 to 5 percent slopes, eroded | 21K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Lawson silt loam, cool mesic, 0 to 2 percent slopes, frequently flooded | 21K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Hickory silt loam, 18 to 35 percent slopes | 20K | Well drained | B | Very limited | Very limited |
| Oconee silt loam, 2 to 5 percent slopes | 18K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Cowden silt loam, 0 to 2 percent slopes | 13K | Poorly drained | C/D | Very limited | Very limited |
| Keller silt loam, 2 to 5 percent slopes, eroded | 12K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Hickory silt loam, 10 to 18 percent slopes, eroded | 9K | Well drained | B | Somewhat limited | Somewhat limited |
| Oconee silt loam, 0 to 2 percent slopes | 9K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Harrison silt loam, 2 to 5 percent slopes | 9K | Moderately well drained | C | Somewhat limited | Very limited |
| Marine silt loam, 2 to 5 percent slopes | 9K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Homen silt loam, 2 to 5 percent slopes | 7K | Moderately well drained | C | Somewhat limited | Very limited |
| Atlas silt loam, 5 to 10 percent slopes, eroded | 6K | Somewhat poorly drained | D | Very limited | Very limited |
| Water | 6K | Not rated | Not rated | ||
| Hickory silt loam, 10 to 18 percent slopes | 6K | Well drained | B | Somewhat limited | Somewhat limited |
| Bunkum-Atlas silt loams, 5 to 10 percent slopes, eroded | 5K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Marine silt loam, 0 to 2 percent slopes | 5K | Somewhat poorly drained | C/D | Very limited | Very limited |
What This Means
Building & Foundations
About 89% 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 94% 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.