Winnebago County, Illinois
The dominant drainage class is Well drained and the dominant hydrologic group is B (moderate infiltration). 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 Winnebago County, Illinois.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Griswold loam, 6 to 12 percent slopes, eroded | 22K | Well drained | B | Somewhat limited | Very limited |
| Comfrey loam, 0 to 2 percent slopes, frequently flooded | 15K | Poorly drained | B/D | Very limited | Very limited |
| Osco silt loam, 2 to 5 percent slopes | 15K | Well drained | B | Somewhat limited | Somewhat limited |
| Ogle silt loam, 2 to 5 percent slopes | 13K | Well drained | B | Somewhat limited | Somewhat limited |
| Greenbush silt loam, 2 to 5 percent slopes | 9K | Well drained | B | Somewhat limited | Somewhat limited |
| Winnebago silt loam, 2 to 5 percent slopes | 9K | Well drained | B | Somewhat limited | Somewhat limited |
| Plano silt loam, 2 to 5 percent slopes | 9K | Well drained | B | Somewhat limited | Very limited |
| Flagler sandy loam, 0 to 2 percent slopes | 9K | Somewhat excessively drained | A | Not limited | Very limited |
| Jasper silt loam, 2 to 5 percent slopes | 7K | Well drained | B | Somewhat limited | Very limited |
| Selmass loam, 0 to 2 percent slopes | 7K | Poorly drained | B/D | Very limited | Very limited |
| Warsaw loam, 0 to 2 percent slopes | 7K | Well drained | B | Not limited | Very limited |
| Hononegah loamy coarse sand, 0 to 2 percent slopes | 6K | Excessively drained | A | Not limited | Very limited |
| Kidder loam, 6 to 12 percent slopes, eroded | 6K | Well drained | B | Somewhat limited | Very limited |
| Water | 5K | Not rated | Not rated | ||
| Lahoguess loam, 0 to 2 percent slopes | 5K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Rockton and Dodgeville soils, 5 to 10 percent slopes, eroded | 5K | Well drained | C | Very limited | Very limited |
| Griswold loam, 2 to 4 percent slopes | 5K | Well drained | B | Not limited | Very limited |
| Drummer silty clay loam, 0 to 2 percent slopes | 5K | Poorly drained | B/D | Very limited | Very limited |
| Jasper silt loam, 0 to 2 percent slopes | 5K | Well drained | B | Not limited | Very limited |
| Lawson silt loam, cool mesic, 0 to 2 percent slopes, occasionally flooded | 4K | Somewhat poorly drained | B/D | Very limited | Very limited |
What This Means
Building & Foundations
About 24% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 69% 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
Drainage is generally favorable for gardening. Adding compost and mulch will improve fertility and water retention. Test your soil's pH before planting — most vegetables prefer 6.0-7.0.