Franklin 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 Franklin County, Illinois.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Belknap silt loam, 0 to 2 percent slopes, frequently flooded | 26K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Bluford silt loam, 0 to 2 percent slopes | 26K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Ava silt loam, 2 to 5 percent slopes | 20K | Moderately well drained | C | Very limited | Very limited |
| Bluford silt loam, 2 to 5 percent slopes, eroded | 16K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Water | 15K | Not rated | Not rated | ||
| Bonnie silt loam, 0 to 2 percent slopes, frequently flooded | 14K | Poorly drained | C/D | Very limited | Very limited |
| Hoyleton silt loam, 0 to 2 percent slopes | 11K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Blair silty clay loam, 5 to 10 percent slopes, severely eroded | 11K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Plumfield silty clay loam, 5 to 10 percent slopes | 10K | Moderately well drained | D | Somewhat limited | Very limited |
| Ava silt loam, 5 to 10 percent slopes, eroded | 9K | Moderately well drained | C | Very limited | Very limited |
| Wynoose silt loam, 0 to 2 percent slopes | 8K | Poorly drained | C/D | Very limited | Very limited |
| Ava silt loam, 2 to 5 percent slopes, eroded | 8K | Moderately well drained | C | Very limited | Very limited |
| Bluford silt loam, bench, 0 to 2 percent slopes | 7K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Wynoose silt loam, bench, 0 to 2 percent slopes | 7K | Poorly drained | C/D | Very limited | Very limited |
| Cisne silt loam, 0 to 2 percent slopes | 6K | Poorly drained | C/D | Very limited | Very limited |
| Rend silt loam, 2 to 5 percent slopes, eroded | 5K | Moderately well drained | C | Very limited | Very limited |
| Cape silty clay loam, 0 to 2 percent slopes, frequently flooded | 5K | Poorly drained | D | Very limited | Very limited |
| Hoyleton silt loam, 2 to 5 percent slopes, eroded | 5K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Hickory clay loam, 10 to 18 percent slopes, severely eroded | 5K | Well drained | B | Somewhat limited | Somewhat limited |
| Grantsburg silt loam, 2 to 5 percent slopes | 4K | Moderately well drained | C | Somewhat limited | Very limited |
What This Means
Building & Foundations
About 84% of soils are rated "very limited" for dwellings with basements. Specific challenges include poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 90% 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.